PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 1994-05-11 NOTE = "Software Interface Specification for the Magellan Global Vector Data Record. Formatted for display or printing at 58 lines per page with up to 80 constant- width characters per line." END_OBJECT = TEXT END Stanford Center for Radar Astronomy Software Interface Specification SU-MGN-GVDR Magellan Global Vector Data Record prepared by Richard A. Simpson Center for Radar Astronomy Stanford University Stanford, CA 94305-4055 415-723-3525 Version 1.0 11 May 1994 PREFACE |================================================================| | | | DOCUMENT CHANGE LOG | | | |================================================================| |REVISION|REVISION| SECTION | REMARKS | | NUMBER | DATE | AFFECTED | | |--------+--------+------------+---------------------------------| | | | | | |================================================================| |================================================================| | | | ITEMS TO BE DETERMINED | | | |================================================================| | REVISION | SECTION | ITEM DESCRIPTION | RESOLUTION | | NUMBER | AFFECTED | | | |----------+----------+------------------------+-----------------| | | | | | |================================================================| Distribution JPL/Magellan T.W. Thompson..........230-260 twthompson@nasamail.nasa.gov R.S. Saunders..........230-260 ssaunders@nasamail.nasa.gov D.L. Conner............230-260 dlc343@mipl3.jpl.nasa.gov D. Senske............230-260 dzf342@ipl.jpl.nasa.gov J.J. Plaut.............230-260 jjp342@mipl3.dnet.nasa.gov JPL/SFDU Control Authority J. Grimes............301-345 jimg@binky.jpl.nasa.gov J. Khatchadourian....301-345 jacob@binky.jpl.nasa.gov PDS/JPL R. Joyner............525/3610 rjoyner@jplpds.jpl.nasa.gov PDS/Washington University R.E. Arvidson...Campus Box 1169 arvidson@wuddy.wustl.edu PDS/MIT P.G. Ford................37-601 pgf@space.mit.edu Stanford University R. Simpson.........Durand 232 rsimpson@nova.stanford.edu M.J. Maurer .........Durand 232 maurer@nova.stanford.edu L. Tyler...........Durand 232 len@nova.stanford.edu Cornell University D.B. Campbell..............NAIC campbell@astrosun.tn.cornell.edu USGS L. Soderblom........Flagstaff lsoderblom@astrog.span.nasa.gov Contents Preface..........................................................i Document Change Log..............................................i Items to be Determined..........................................ii Distribution...................................................iii Contents........................................................iv Acronyms and Abbreviations.....................................vii 1 Introduction..................................................1 1.1 Overview....................................................1 1.2 Scope.......................................................1 1.3 Applicable Documents........................................1 1.4 System Siting...............................................2 1.4.1 Interface Location and Medium.............................2 1.4.2 Data Sources, Destinations, and Transfer Methods..........2 1.4.3 Generation Method and Frequency...........................2 1.5 Assumptions and Constraints.................................2 1.5.1 Usage Constraints.........................................2 1.5.2 Documentation Conventions.................................3 1.5.2.1 Data Format Descriptions................................3 1.5.2.2 Limits of This Document.................................3 1.5.2.3 Typographic Conventions.................................3 1.5.3 Time Standards............................................3 2 Interface Characteristics.....................................4 2.1 Hardware Characteristics and Limitations....................4 2.1.1 Special Equipment and Device Interfaces...................4 2.1.2 Special Set-Up Requirements...............................4 2.2 Volume and Size ............................................4 2.3 Labeling and Identification.................................4 2.3.1 External Labels...........................................4 2.3.2 Internal Labels...........................................4 2.4 Interface Medium Characteristics............................4 2.5 Backup and Duplicates.......................................4 3 Structure and Organization Overview...........................5 3.1 Disc Organization...........................................5 3.1.1 Root Directory............................................6 3.1.2 CATALOG Directory.........................................6 3.1.3 DOCUMENT Directory........................................6 3.1.4 INDEX Directory...........................................6 3.1.5 SOFTWARE Directory........................................7 3.1.6 GVDR Directory............................................7 3.2 Formats.....................................................7 3.3 File Naming Conventions.....................................7 3.3.1 PDS Labels................................................7 3.3.2 Document Files............................................8 3.3.3 Tabular Files.............................................8 3.3.4 Catalog Files.............................................9 3.3.5 Software Files............................................9 4 Detailed Interface Specifications............................11 4.1 Root Files.................................................11 4.1.1 AAREADME.TXT File........................................11 4.1.2 ERRATA.TXT File..........................................11 4.1.3 VOLDESC.CAT File.........................................11 4.1.3.1 Keywords and Values....................................13 4.2 Static Directories.........................................15 4.2.1 CATALOG Directory........................................15 4.2.1.1 CATINFO.TXT File.......................................15 4.2.1.2 *.CAT Files............................................15 4.2.1.3 Image Map Projection Files.............................15 4.2.1.4 Data Set Map Projection File...........................16 4.2.2 DOCUMENT Directory.......................................16 4.2.2.1 DOCINFO.TXT File.......................................16 4.2.2.2 GVDRSIS.TXT File.......................................16 4.2.2.3 TILING.TXT File........................................16 4.2.3 INDEX Directory..........................................17 4.2.3.1 INDXINFO.TXT File......................................17 4.2.3.2 INDEX.LBL File.........................................17 4.2.3.3 INDEX.TAB File.........................................17 4.2.3.4 CUMINDEX.LBL File......................................17 4.2.3.5 CUMINDEX.TAB File......................................17 4.2.3.6 INDEX.FMT File.........................................17 4.2.4 SOFTWARE Directory.......................................18 4.2.4.1 SOFTINFO.TXT File......................................18 4.2.4.2 SOURCE Directory.......................................18 4.2.4.3 SUN4 Directory.........................................18 4.2.4.4 DECMIPS Directory......................................18 4.3 GVDR Directory (Data Directories)..........................18 5 Support Staff and Cognizant Personnel........................21 A Example PDS Labels and Structure Definitions................A-1 A.1 GVADF.FMT Example File...................................A-1 A.2 GVADF.LBL Example File...................................A-3 A.3 GVANF.FMT Example File...................................A-5 A.4 GVANF.LBL Example File...................................A-9 A.5 GVGEO.FMT Example File..................................A-10 A.6 GVGEO.LBL Example File..................................A-22 A.7 GVHDR.FMT Example File..................................A-23 A.8 GVHDR.LBL Example File..................................A-34 A.9 GVNFF.FMT Example File..................................A-35 A.10 GVORB.FMT Example File..................................A-38 A.11 GVORB.LBL Example File..................................A-39 A.12 GVPIDX.FMT Example File.................................A-40 A.13 GVPIDX.LBL Example File.................................A-42 A.14 GVRDF.FMT Example File..................................A-43 A.15 GVRDF.LBL Example File..................................A-47 A.16 GVTGEOM.FMT Example File................................A-48 A.17 GVTGEOM.LBL Example File................................A-50 A.18 GVTIDX.FMT Example File.................................A-51 A.19 GVTIDX.LBL Example File.................................A-53 A.20 GVXIF.FMT Example File..................................A-56 A.21 GVXIF.LBL Example File..................................A-60 A.22 INDEX.FMT Example File..................................A-62 A.23 INDEX.LBL Example File..................................A-63 Tables 4-2-1-2 *.CAT Files in the GVDR CATALOG Directory.............15 4-2-1-3 Image Map Projection Files............................16 4-3 GVDR Data Files.......................................20 Figures 3-1 Example Top-Level GVDR Directory Structure.............5 4-1-1 Example Label for GVDR TXT Files......................11 4-1-3 Example VOLDESC.CAT File..............................12 4-3 Example GVDR Data Directory Structure.................19 Acronyms and Abbreviations ADC Archival Data Collection AMMOS Advanced Multi-Mission Operations System ANSI American National Standards Institute ARCDR Altimetry and Radiometry Composite Data Record ASCII American Standard Code for Information Interchange ATDF Archival Tracking Data File CCSDS Consultative Committee for Space Data Systems CD Compact Disc CD-WO Compact Disc - Write Once CNES Centre National d'Etudes Spatiales DAT Data Administration Team DARWG Data and Archiving Working Group DOS Disk Operating System DSN Deep Space Network EOF End of File GDS Ground Data System GSFC Goddard Space Flight Center GVDR Global Vector Data Record ISO International Standards Organization JPL Jet Propulsion Laboratory K Degrees Kelvin kB Kilobytes MB Megabytes MIT Massachusetts Institute of Technology MO Mars Observer MSB Most Significant Byte NAIF Navigation and Ancillary Information Facility NASA National Aeronautics and Space Administration NAV Navigation Subsystem/Team NERT Near Real Time ODF Orbit Data File OIDR Original and Intermediate Data Records PDB Project Data Base PDS Planetary Data System PSG Project Science Group ROM Read-Only Memory RS Radio Science RST Radio Science Team SCVDR Surface Characteristics Data Vector SDP Science Data Products SDVT Science Data Validation Team SFDU Standard Formatted Data Unit SIS Software Interface Specification SOPC Science Operations Planning Computer TBD To Be Determined 1 Introduction 1.1 Overview This Software Interface Specification (SIS) describes the format and content of the Magellan Global Vector Data Record (GVDR). The GVDR is derived primarily from the Surface Characteristics Vector Data Record (SCVDR) produced at Stanford University [5] and the Altimetry and Radiometry Composite Data Record (ARCDR) produced at the Massachusetts Institute of Technology (MIT) [4]. Each is an orbit-by-orbit compilation of Magellan scattering and radiometry results. Data from the SCVDR and ARCDR are averaged and binned in cells with dimensions of 18.225 km for the GVDR. Each bin contains an average nadir backscattering function from Magellan altimetry data, a subset of altimetry results from the ARCDR, composite oblique backscatter functions from the Magellan SAR, and estimates of emissivity from the radiometer. Each multi-dimensional "pixel" of scattering and radiometry data is ordered within a "tile" of other contiguous pixels in one of four global map projections. The GVDR consists of one or more Compact Disc - Write Once (CD-WO) media, each CD-WO representing a single "volume" of data. The GVDR is created at Stanford University. The GVDR is a deliverable product to the Magellan Project. It is also a deliverable to the Planetary Data System (PDS) and the scientific community that it supports. The formats of all files in the GVDR are based on PDS standards (Version 3) [2]. 1.2 Scope The specifications in this document apply to all volumes containing GVDR data produced at Stanford University. This document provides a detailed description of the GVDR interface. 1.3 Applicable Documents [1] ISO 9660-1988. Information Processing - Volume and File Structure on CD-ROM for Information Exchange, 15 April 1988. [2] Planetary Data System Standards Reference, JPL D-7669, part 2, 20 November 1992 [3] Planetary Science Data Dictionary, JPL D-7116, Rev. C, 20 November 1992 [4] Hyon, J., and M. White, Altimetric and Radiometric Composite Data Record Compact Disc-Read Only Memory (ARCDR CD-ROM), Project Magellan Software Interface Specification IDPS-146, Jet Propulsion Laboratory, Pasadena, CA, 14 August 1991. [5] Simpson, R.A., J.D Twicken, and M.J. Maurer, Surface Characteristics Vector Data Record, Software Interface Specification SU-MGN-SCVDR, Stanford University, Stanford, CA, 1 October 1992. [6] Planetary Data System, Data Preparation Workbook, JPL Publication D-7669, Part 1, Version 3.0, 21 April 1993. [7] Hess, S., Streamlined PDS Templates, Internet Message ID 931001144716.21801d14@JPLPDS.JPL.NASA.GOV, 1 October 1993. 1.4 System Siting 1.4.1 Interface Location and Medium GVDR volumes are created at Stanford University using the Mars Observer (MO) Radio Science (RS) Science Operations Planning Computer (SOPC) and the Young Minds CD-Studio compact disc authoring subsystem. All volumes intended for delivery to PDS will be on CD-WO media [1]. 1.4.2 Data Sources, Destinations, and Transfer Methods Each GVDR volume is a collection of products representing, derived from, or needed to analyze Magellan radar and radiometry data. The primary input products are the ARCDR CD-ROM [4] and the SCVDR [5]. Each GVDR CD-WO is delivered using the most appropriate means to the Magellan Project and the Planetary Data System (PDS). 1.4.3 Generation Method and Frequency Several steps are required to convert the input data products to the GVDR. The principal input products are files from the ARCDR CD and SCVDR, all of which are organized by orbit number, each orbit organized by footprint number. The ultimate goal of GVDR processing is to reorganize the data in these files by geographic location, so that all observations of a single location on the planet, from any orbit, are collected together. The first step in GVDR production is to extract the few quantities of interest from each of the several million ARCDR and SCVDR footprints. This distillation process results in an intermediate data set of a more manageable size, but still ordered by footprint rather than by geographic location. The second step is to examine each of the footprints in this intermediate data set and record which GVDR pixels are within its observation area. This results in an index of footprints ordered by geographic location. The third step is to combine this index with the observations into the GVDR pixels themselves. This stage is the first and only occasion in which any of the observational quantities are altered by the GVDR processing, and the alteration is limited to a weighted averaging of the input quantities. The fourth and final step is a simple reformatting to comply with PDS labeling conventions. A preliminary GVDR will be issued based primarily on Magellan Cycle 1 data. While the preliminary GVDR is being reviewed, the remaining Magellan data will undergo SCVDR processing. After corrections resulting from review of the preliminary GVDR have been made, the final GVDR (incorporating all data from Magellan Cycles 1-3) will be issued. 1.5 Assumptions and Constraints 1.5.1 Usage Constraints Access to the GVDR volumes will be determined by the Magellan Project and PDS. 1.5.2 Documentation Conventions 1.5.2.1 Data Format Descriptions Data are stored in fields of 8-, 16-. and 32-bit unsigned integers and as character strings. The integers are stored in IEEE most- significant-byte (MSB) format [2]; the first byte contains the most significant bits, while the last contains the least significant bits. If a field is described as containing n bytes of ASCII character string data, this implies that the leftmost (lowest numbered) byte contains the first character, the next lowest byte contains the next character, and so forth. Character strings are written to CD-WO with lower numbered bytes preceding higher numbered bytes. 1.5.2.2 Limits of This Document This document applies only to GVDR volumes. 1.5.2.3 Typographic Conventions This document has been formatted for simple electronic file transfer and display. Line lengths are limited to 80 ASCII characters, including line delimiters. The last two characters on each line are the carriage-return (ASCII 13) and the line-feed (ASCII 10). No special fonts or structures are included within the file. Constant width characters are assumed for display. Hard copy pagination at the rate of 58 lines per page is assumed. For page numbers consistent with those shown in the Table of Contents, breaks in page numbering immediately before "PREFACE" and immediately before "1. Introduction" will be required. 1.5.3 Time Standards Within GVDR files, times are expressed as a string of 19 or 23 ASCII characters YYYY-MM-DDThh:mm:ss[.fff] where "-", "T", ":", and "." are fixed delimiters; "YYYY" is the year "19nn" or "20nn"; "MM" is a two-digit month of year; "DD" is a two-digit day of month; "T" separates the date and time segments of the string; "hh" is hour of day; "mm" is the minutes of hour (00-59); "ss" is the seconds of minute (00-59); and ".fff" gives the fractional seconds. The data type "TIME" is assigned to this format. When only the date is required the 10-character string YYYY-MM-DD may be substituted. The data type "DATE" is assigned to this format. 2 Interface Characteristics 2.1 Hardware Characteristics and Limitations 2.1.1 Special Equipment and Device Interfaces GVDR volumes conform to ISO 9660 standards for CD-ROM [1]. Users of the volumes must have access to systems which can read these media. 2.1.2 Special Set-Up Requirements None. 2.2 Volume and Size Each GVDR volume contains a set of data and ancillary files. The first GVDR will be based on Magellan Cycle 1 data and is expected to fill a single CD-WO volume -- at most, 650 Mbytes of data. Subsequent versions of the GVDR may require more than one CD-WO volume. 2.3 Labeling and Identification 2.3.1 External Labels Each GVDR volume bears a label using the following format: ACRONYM_SEQUENCE;VERSION where ACRONYM = GVDR SEQUENCE = a four digit number indicating the order in which the CD-WO volumes were produced, starting from 0001. VERSION = a single digit determining version number of the CD-WO volume. "1" is the original version. For example, GVDR_0003;5 is the fifth version of the third GVDR volume. 2.3.2 Internal Labels The contents of each GVDR volume will be labeled in accordance with PDS standards. Labeling is described further in subsequent sections. 2.4 Interface Medium Characteristics Each GVDR volume conforms to ISO 9660 standards [1]. The quantity of data stored is no more than 650 MB per disc. 2.5 Backup and Duplicates The entire contents of each GVDR volume will be backed up onto 8 mm tapes and retained at Stanford. At least two copies of each final GVDR volume will be created. One copy will be delivered to PDS and one copy will be retained at Stanford. 3 Structure and Organization Overview 3.1 Disc Organization Each GVDR volume contains a CATALOG directory, a DOCUMENT directory, an INDEX directory, a SOFTWARE directory, and a GVDR (data) directory (Figure 3-1). |================================================================| | | | Figure 3-1 Example Top-Level GVDR Directory Structure | | | |================================================================| | | | root | | | | | |- AAREADME.TXT | | |- ERRATA.TXT | | |- VOLDESC.CAT | | | | | |- CATALOG | | | | | | | |---------------------------------------- | | | | | | | | | |- CATINFO.TXT |- RDRSINST.CAT |- IMPNORTH.LBL | | | |- MISSION.CAT |- REFS.CAT |- IMPSOUTH.LBL | | | |- SC_HOST.CAT |- PERSONEL.CAT |- IMPSINU.LBL | | | |- GVDR_DS.CAT |- IMPMERC.LBL | | | |- DSMP.LBL | | |- DOCUMENT | | | | | | | |- DOCINFO.TXT | | | |- GVDRSIS.TXT | | | |- TILING.TXT | | | | | |- INDEX | | | | | | | |--------------------------------- | | | | | | | | | |- INDXINFO.TXT |- INDEX.LBL |- CUMINDEX.LBL | | | |- INDEX.FMT |- INDEX.TAB |- CUMINDEX.TAB | | | | | |- SOFTWARE | | | | | | | |----------------------------------------- | | | | | | | | | | SOFTINFO.TXT SOURCE SUN4 DECMIPS | | | | | |- GVDR | | | | | | | |--------------------------------------------- | | | | | | | | | | SINU MERC NORTH SOUTH | | | |================================================================| 3.1.1 Root Directory The root directory contains the following files: AAREADME.TXT terse description of volume contents [2] ERRATA.TXT overview of anomalies and errors [2] VOLDESC.CAT volume object definition [2] 3.1.2 CATALOG Directory The CATALOG directory contains the following files: CATINFO.TXT text description of the directory contents [2] MISSION.CAT PDS data set catalog object for Mission [7] SC_HOST.CAT PDS data set catalog object for instrument host (spacecraft) [7] RDRSINST.CAT PDS data set catalog object for instrument [7] REFS.CAT PDS data set catalog object for references [7] PERSONEL.CAT PDS data set catalog object for personnel [7] GVDR_DS.CAT PDS data set catalog object for data set [7] IMPxxxx.LBL PDS image map projection objects for the following projections: north polar stereographic (xxxx = NORTH) south polar stereographic (xxxx = SOUTH) sinusoidal equal area (xxxx = SINU) Mercator (xxxx = MERC) [2] DSMP.LBL PDS data set map projection object [2] 3.1.3 DOCUMENT Directory The DOCUMENT directory contains the following files: DOCINFO.TXT text description of the directory contents [2] GVDRSIS.TXT this SIS document TILING.TXT text description of data tiling procedure 3.1.4 INDEX Directory The INDEX directory contains the following files: INDXINFO.TXT text description of the directory contents [2] INDEX.LBL PDS label for the volume index (INDEX.TAB); identifies the volume index and describes structure of the index table [2] INDEX.TAB volume index in tabular form [2] CUMINDEX.LBL PDS label for the cumulative volume index (CUMINDEX.TAB) [2] CUMINDEX.TAB index in tabular form for all volumes in the in the GVDR data set [2] INDEX.FMT structure object used in association with INDEX.LBL and CUMINDEX.LBL 3.1.5 SOFTWARE Directory Each GVDR volume contains a SOFTWARE directory in which source code and binary executables are stored. The SOFTWARE directory contains: SOFTINFO.TXT text description of the directory contents [2] SOURCE subdirectory containing source code for programs and subroutines SUN4 subdirectory containing executable routines generated for a Sun SPARC-2 using SunOS 4.1.2. DECMIPS subdirectory containing executable routines generated for a DEC DS-5000 workstation using Ultrix 4.2a. 3.1.6 GVDR Directory Each GVDR volume contains directories for one or more GVDR projections (Figure 3-1). These are located in the GVDR (data) directory and include SINU sinusoidal equal-area projection MERC Mercator projection NORTH polar stereographic (north pole) SOUTH polar stereographic (south pole) 3.2 Formats GVDR volumes conform to the ISO 9660 level 1 Interchange Standard CD-WO format [1], which is compatible with common computer systems including MS-DOS, Macintosh, SunOS, and VMS. Data that comprise the GVDR volumes are formatted in accordance with Planetary Data System specifications [2-3,6]. 3.3 File Naming Conventions In this document and on the discs themselves, file and directory names are in upper case characters. This ensures compatibility with operating systems in which these names are case insensitive (e.g., VMS and DOS) and operating systems in which names are automatically translated into one case or the other (e.g., Unix and MacOS). Within disc directories the characters ";1" are appended to all file names. VMS excepted, most operating systems will hide these suffixes from users. 3.3.1 PDS Labels All files contained on GVDR volumes (with the exception of source code, binary executable files, and compressed files in the SOFTWARE directory) are accompanied by PDS labels [2-3,6]. The label can either be prepended to the associated primary file or "detached", in which case the label becomes a file in its own right with the same name as the primary file except for the suffix ".LBL". Detached label files will generally be located in the same directory as the primary file. In cases where the same information is repeated in many labels, a single copy of that information may be located in the CATALOG directory. PDS labels, whether prepended to or detached from their primary file provide descriptive information about the associated file. The PDS label is an object-oriented structure consisting of sets of "keyword=value" declarations. The object to which the label refers (e.g. IMAGE, TABLE, etc.) is denoted by a statement of the form: ^object = location in which the carat character (^, also called a pointer in this context) indicates where to find the object. In a prepended label, the location is an integer representing the starting record or byte number of the object, where counting starts from record or byte number 1. In a detached label, the location denotes the name of the file containing the object, along with the starting record or byte number if there is more than one object. For example: ^HEADER = ("F01.IMG",1) ^IMAGE = ("F01.IMG",1025 ) indicates that the IMAGE object begins at byte 1025 of the file F01.IMG, in the same directory as the detached label file. Below is a list of the possible formats for the ^object definition. ^object = n ^object = n ^object = "filename.ext" ^object = ("filename.ext",n) ^object = ("filename.ext",n) where n is the starting record or byte number of the object, counting from the beginning of the file (record 1 or byte 1), indicates that the number given is in units of bytes; default is RECORDS filename is the (up to) 8 character, alphanumeric upper-case file name, ext is the 3 character upper-case file extension, All detached labels will have lengths that are multiples of 80 bytes, but individual records will have variable lengths. Each record will end with a carriage return character (ASCII 13) in the next-to-last byte and a line feed character (ASCII 10) in the last byte. 3.3.2 Document Files Document files (.TXT suffix) may exist in the root, CATALOG, DOCUMENT, SOFTWARE, and INDEX directories. These are ASCII files with embedded PDS labels which employ the TEXT object. All records in document files are limited to 80-bytes, with a carriage return character (ASCII 13) in the next-to-last byte and a line feed character (ASCII 10) in the last byte. 3.3.3 Tabular Files Tabular files (.TAB suffix) exist in the INDEX directory (where they are ASCII files formatted for direct reading into many database management systems) and in the GVDR (data) subdirectories (where they may be either ASCII or binary). ASCII tabular files consist of data "fields" separated by commas. Character fields are also enclosed in double quotation marks (") and are padded with spaces to keep quotation marks in the same columns of successive records. Character fields are left justified, and numeric fields are right justified. The "start byte" and "bytes" values listed in the labels do not include the commas between fields or the quotation marks surrounding character fields. The records in tabular files have fixed length, and the last two bytes of each record contain the ASCII carriage return and line feed characters. This allows a table to be treated as a fixed length record file on computers that support this file type and as a text file with embedded line delimiters on those that do not. Binary tabular files also consist of data "fields". Positions and lengths of the fields are specified exactly by an accompanying detached PDS label. Records have fixed lengths; fields within records are also fixed. There generally are no special delimiters (e.g., commas, carriage-returns, or line feeds) or quotation marks setting off the contents of the fields or records. All tabular files are accompanied by descriptive, detached PDS labels. The PDS label has the same name as the data file it describes, except for the extension .LBL. For example, the file INDEX.TAB is accompanied by the detached label file INDEX.LBL in the INDEX directory. Some labels have associated structure definition files which also have the same name except for the extension .FMT. 3.3.4 Catalog Files Catalog files (suffix .CAT) exist in the root and in the CATALOG directory. They are formatted in an object-oriented structure consisting of sets of "keyword=value" declarations. VOLDESC.CAT in the root provides an overview of the contents of the volume in the form of a completed PDS template. The files in the CATALOG directory provide a top-level understanding of the mission, instrument and data set. They are presented in the form of completed PDS templates [7]. 3.3.5 Software Files Software files exist in the SOFTWARE directory, where they may appear in three forms. Source code is stored as ASCII character strings in the SOURCE subdirectory. Line lengths are not limited and may exceed 80 characters. File name suffixes (e.g., .F, .F77, or .C) may be used to indicate the expected compiler. Unix-style Makefiles and other files intended for immediate use with software are considered to be "source code". Some source code has been compressed to facilitate distribution. Compressed files are stored in the DISTRIB subdirectory within the SOURCE directory. More information on this file type may be found in SOFTINFO.TXT in the SOFTWARE directory. Binary executable files may be stored in the subdirectories SUN4 and DECMIPS for use on a Sun SPARCstation running SunOS 4.1.2 or a Digital DS-5000 workstation running the Ultrix 4.2a operating system, respectively. Source code, binary executable files, and compressed files do NOT have PDS labels. 4 Detailed Interface Specifications 4.1 Root Files 4.1.1 AAREADME.TXT File The AAREADME.TXT file contains terse volume content and format information. This is an ASCII file with record lengths no longer than 80 bytes. Each line is terminated with a carriage-return (ASCII 13) line-feed (ASCII 10) pair. The file has an attached PDS label of the form shown in Figure 4-1-1. |================================================================| | | | Figure 4-1-1 Example Label for GVDR TXT Files | | | |================================================================| | | | PDS_VERSION_ID = PDS3 | | RECORD_TYPE = STREAM | | OBJECT = TEXT | | PUBLICATION_DATE = 1994-02-15 | | NOTE = "Software Interface Specification | | for the Magellan Global Vector | | Data Record. Formatted for | | display or printing at 58 lines | | per page with up to 70 constant- | | width characters per line." | | END_OBJECT = TEXT | |================================================================| Labeling requirements applicable to Figure 4-1-1 are described in [2]; keywords are defined in [3]. For this application, the only keywords that change are PUBLICATION_DATE the date in YYYY-MM-DD format on which the file was created or last modified (see Section 1.5.3). NOTE a brief description of the file, including a title if available. 4.1.2 ERRATA.TXT File ERRATA.TXT contains a cumulative listing of comments and updates concerning all GVDR volumes published to date. This is an ASCII file with record lengths no longer than 80 bytes. Each line is terminated with a carriage-return (ASCII 13) line-feed (ASCII 10) pair. The file has an attached PDS label of the form shown in Figure 4-1-1. 4.1.3 VOLDESC.CAT File VOLDESC.CAT contains a description of the contents of this volume in a PDS format readable by both humans and computers. This is an ASCII file with fixed length records of 72 bytes. Each line is terminated with a carriage-return (ASCII 13) line-feed (ASCII 10) pair. Figure 4-1-3 shows a sample VOLDESC.CAT file for the first GVDR volume. |================================================================| | | | Figure 4-1-3 Example VOLDESC.CAT File | | | |================================================================| | | | PDS_VERSION_ID = PDS3 | | | | OBJECT = VOLUME | | VOLUME_SERIES_NAME = "MISSION TO VENUS" | | VOLUME_SET_NAME = "MAGELLAN RADAR DATA PRODUCTS" | | VOLUME_SET_ID = USA_NASA_JPL_GVDR_0001 | | VOLUMES = 1 | | VOLUME_NAME = "MAGELLAN GLOBAL VECTOR DATA RECORD" | | VOLUME_ID = "GVDR_0001" | | VOLUME_VERSION_ID = "VERSION 1" | | PUBLICATION_DATE = 1994-02-15 | | DATA_SET_ID = "MGN-V-RDRS-5-GVDR-V1.0" | | MEDIUM_TYPE = "CD-WO" | | VOLUME_FORMAT = "ISO-9660" | | DESCRIPTION = "This volume contains composite radar | | scattering functions derived from | | Magellan synthetic aperture radar, | | altimetry, and radiometry. Results | | are stored in ASCII and binary tables| | linked to pixels with 18.225 km | | resolution. Pixels are organized in | | sinusoidal equal area, Mercator, | | north polar stereographic, and south | | polar stereographic projections." | | MISSION_NAME = "MAGELLAN" | | SPACECRAFT_NAME = "MAGELLAN" | | SPACECRAFT_ID = MGN | | OBJECT = DATA_PRODUCER | | INSTITUTION_NAME = "STANFORD UNIVERSITY" | | FACILITY_NAME = "MO RS REMOTE MISSION SUPPORT AREA" | | FULL_NAME = "MICHAEL J. MAURER" | | ADDRESS_TEXT = "DURAND BLDG - ROOM 232 | | STANFORD UNIVERSITY | | STANFORD, CA 94305-4055" | | END_OBJECT = DATA_PRODUCER | | OBJECT = CATALOG | | ^MISSION_CATALOG = "MISSION.CAT" | | ^INSTRUMENT_HOST_CATALOG = "SC_HOST.CAT" | | ^INSTRUMENT_CATALOG = "RDRSINST.CAT" | | ^REFERENCE_CATALOG = "REFS.CAT" | | ^PERSONNEL_CATALOG = "PERSONEL.CAT" | | ^DATA_SET_CATALOG = "GVDR_DS.CAT" | | END_OBJECT = CATALOG | | END_OBJECT = VOLUME | | END | | | |================================================================| 4.1.3.1 Keywords and Values Keywords in Figure 4-1-3 are defined in [3]. They are used in this application as follows: PDS_VERSION_ID The version of PDS standards to which this volume adheres; set to "PDS3". VOLUME_SERIES_NAME The formal name that describes a broad categorization of data products. For the GVDR, set to "MISSION TO VENUS". VOLUME_SET_NAME The formal name describing one or more volumes containing a single data set or a collection of related data sets. For the GVDR, set to "MAGELLAN RADAR DATA PRODUCTS". VOLUME_SET_ID Identification of a data volume or a set of archive data volumes. For the GVDR, set to "USA_NASA_JPL_ACRONYM_SEQUENCE" where ACRONYM and SEQUENCE are defined in Section 2.3.1. See also VOLUME_ID, below. VOLUMES The number of physical volumes in a volume set. Volume sets of GVDR data will generally be single volumes, so this value will be set to "1". VOLUME_NAME The formal name of the individual GVDR volume; a more specific identification than VOLUME_SET_NAME. For the GVDR, set to "MAGELLAN GLOBAL VECTOR DATA RECORD". VOLUME_ID A unique identifier for the volume. Usually the last two components of the VOLUME_SET_ID (see also Section 2.3.1). For the GVDR, set to "GVDR_0001". VOLUME_VERSION_ID The version of the data volume, starting with "1" for original versions and incrementing by 1 for each subsequent version. PUBLICATION_DATE The date in YYYY-MM-DD format on which the volume was published or released (see Section 1.5.3). DATA_SET_ID A unique alphanumeric identifier for the data set. For the GVDR, set to "MGN-V-RDRS-5-GVDR-V1.0". MEDIUM_TYPE The physical storage medium for the GVDR volume. Set to "CD-WO". VOLUME_FORMAT The logical format used in writing the GVDR volume. Set to "ISO-9660". DESCRIPTION A brief text description of the contents of the GVDR volume. MISSION_NAME The planetary mission or project under which the data were acquired. A single mission may be associated with one or more spacecraft. For the GVDR, set to "MAGELLAN". SPACECRAFT_NAME The full name of the spacecraft with which these data are associated. For the GVDR, set to "MAGELLAN". SPACECRAFT_ID A mnemonic uniquely associated with SPACECRAFT_NAME. For the GVDR, set to "MGN". INSTITUTION_NAME The name of the institution under which this GVDR volume was produced. Set to "STANFORD UNIVERSITY". FACILITY_NAME The name of the department, laboratory, or subsystem under which this GVDR volume was produced. Set to "MO RS REMOTE MISSION SUPPORT AREA". FULL_NAME The name of the individual or organization responsible for producing this GVDR volume. For the GVDR, set to "MICHAEL J. MAURER". ADDRESS_TEXT Mailing address for the individual or organization responsible for producing this GVDR volume. For the GVDR, set to "DURAND BLDG - ROOM 232 STANFORD UNIVERSITY STANFORD, CA 94305-4055". ^MISSION_CATALOG File name in the CATALOG directory under which the PDS streamlined mission template is stored. Set to "MISSION.CAT". ^INSTRUMENT_HOST_CATALOG File name in the CATALOG directory under which the PDS streamlined instrument host template is stored. Set to "SC_HOST.CAT". ^INSTRUMENT_CATALOG File name in the CATALOG directory under which the PDS streamlined instrument template is stored. Set to "RDRSINST.CAT". ^REFERENCE_CATALOG File name in the CATALOG directory under which the PDS streamlined reference template is stored. Set to "REFS.CAT". ^PERSONNEL_CATALOG File name in the CATALOG directory under which the PDS streamlined personnel template is stored. Set to "PERSONEL.CAT". ^DATA_SET_CATALOG File name in the CATALOG directory under which the PDS streamlined data set template is stored. Set to "GVDR_DS.CAT". 4.2 Static Directories Static directories are those which do not change (or change very little) from one volume to another. They appear on all volumes. 4.2.1 CATALOG Directory The CATALOG directory contains files used in cataloging the data, including files which provide high-level descriptions of the planetary mission, spacecraft, instrument, and data set. PDS "streamlined" template forms are used [7]. 4.2.1.1 CATINFO.TXT File The CATINFO.TXT file contains a description of the contents of the CATALOG directory. This is an ASCII file with record lengths no longer than 80 bytes. Each line is terminated with a carriage-return (ASCII 13) line-feed (ASCII 10) pair. The file has an attached PDS label of the form shown in Figure 4-1-1. 4.2.1.2 *.CAT Files The *.CAT files contain PDS high-level descriptions and catalog information about the Magellan mission, spacecraft, radar instrument, and data set [7]. Each is an ASCII file with fixed length records of 72 bytes. Each line is terminated with a carriage-return (ASCII 13) line- feed (ASCII 10) pair in positions 71 and 72, respectively. The files are listed in Table 4-2-1-2. |=====================================================================| | | | Table 4-2-1-2 *.CAT Files in the GVDR CATALOG Directory | | | |=====================================================================| | File Name | Contents | |==============|======================================================| | MISSION.CAT | Magellan mission, spacecraft, and science objectives | |--------------+------------------------------------------------------| | SC_HOST.CAT | Magellan spacecraft description and data | |--------------+------------------------------------------------------| | RDRSINST.CAT | Magellan radar system description and data | |--------------+------------------------------------------------------| | GVDR_DS.CAT | GVDR data set description | |--------------+------------------------------------------------------| | PERSONEL.CAT | Information on personnel involved in compiling and | | | distributing the GVDR | |--------------+------------------------------------------------------| | REFS.CAT | References cited in other *.CAT files | |=====================================================================| 4.2.1.3 Image Map Projection Files The four image map projection files contain PDS high-level descriptions of each of the image map projections used in the GVDR. Each is an ASCII file with record lengths of 80 bytes. Each line is terminated by a carriage-return (ASCII 13) line-feed (ASCII 10) pair in positions 79 and 80, respectively. The files and their projections are listed in Table 4-2-1-3. |=============================================| | | | Table 4-2-1-3 Image Map Projection Files | | | |=============================================| | File Name | Projection | |==============+==============================| | IMPNORTH.LBL | North polar stereographic | |--------------+------------------------------| | IMPSOUTH.LBL | South polar stereographic | |--------------+------------------------------| | IMPSINU.LBL | Sinusoidal equal area | |--------------+------------------------------| | IMPMERC.LBL | Mercator | |=============================================| 4.2.1.4 Data Set Map Projection File The DSMP.LBL file contains a PDS high-level description of the map projections used in the GVDR data set. It is an ASCII file with record lengths of 80 bytes. East line is terminated by a carriage-return (ASCII 13) line-feed (ASCII 10) pair in positions 79 and 80, respectively. 4.2.2 DOCUMENT Directory The DOCUMENT directory contains files which describe the data included in the GVDR volume. 4.2.2.1 DOCINFO.TXT File The DOCINFO.TXT file contains a description of the contents of this directory. This is an ASCII file with record lengths no longer than 80 bytes. Each line is terminated with a carriage-return (ASCII 13) line-feed (ASCII 10) pair. The file has an attached PDS label of the form shown in Figure 4-1-1. 4.2.2.2 GVDRSIS.TXT File The GVDRSIS.TXT file is the Software Interface Specification for the GVDR (this document). This is an ASCII file with fixed length records of 80 bytes. Each line is terminated with a carriage-return (ASCII 13) line-feed (ASCII 10) pair. The file has an attached PDS label of the form shown in Figure 4-1-1. 4.2.2.3 TILING.TXT File The TILING.TXT file is a text description of the tiling algorithm adopted for the GVDR. This is an ASCII file with records of no more than 80 bytes. Each line is terminated with a carriage-return (ASCII 13) line-feed (ASCII 10) pair. The file has an attached PDS label of the form shown in Figure 4-1-1. 4.2.3 INDEX Directory 4.2.3.1 INDXINFO.TXT File The INDXINFO.TXT file contains a description of the contents of the INDEX directory. This is an ASCII file with record lengths no longer than 80 bytes. Each line is terminated with a carriage-return (ASCII 13) line-feed (ASCII 10) pair. The file has an attached PDS label of the form shown in Figure 4-1-1. 4.2.3.2 INDEX.LBL File INDEX.LBL is a detached label that completely describes INDEX.TAB. This is an ASCII file with record lengths no longer than 80 bytes. Each line is terminated with a carriage-return (ASCII 13) line-feed (ASCII 10) pair. An example INDEX.LBL file for a GVDR volume is shown in Appendix A. Keywords are defined in [3]. 4.2.3.3 INDEX.TAB File INDEX.TAB is a table listing all GVDR data files published in this volume. It is an ASCII file with fixed-length records. Each record is delimited by a carriage-return (ASCII 13) line-feed (ASCII 10) pair. The detailed format and content are described completely by INDEX.LBL. 4.2.3.4 CUMINDEX.LBL File CUMINDEX.LBL is a detached label that completely describes CUMINDEX.TAB. This is an ASCII file with record lengths no longer than 80 bytes. Each line is terminated with a carriage-return (ASCII 13) line-feed (ASCII 10) pair. Keywords are defined in [3]. CUMINDEX.LBL differs from INDEX.LBL (see Appendix A) in only three ways: * DESCRIPTION should refer to CUMINDEX.TAB rather than to INDEX.TAB * ^TABLE points to CUMINDEX.TAB rather than to INDEX.TAB * INDEX_TYPE = CUMULATIVE rather than SINGLE 4.2.3.5 CUMINDEX.TAB File CUMINDEX.TAB is a table listing all GVDR data files published in all volumes of the volume set to date. It is an ASCII file with fixed- length records. Each record is delimited by a carriage-return (ASCII 13) line-feed (ASCII 10) pair. The detailed format and content are described completely by CUMINDEX.LBL. 4.2.3.6 INDEX.FMT File INDEX.FMT is a structure file used in conjunction with INDEX.LBL and CUMINDEX.LBL to describe INDEX.TAB and CUMINDEX.TAB, respectively. This is an ASCII file with record lengths no longer than 80 bytes. Each line is terminated with a carriage-return (ASCII 13) line-feed (ASCII 10) pair. An example INDEX.FMT file for a GVDR volume is shown in Appendix A. Keywords are defined in [3]. 4.2.4 Software Directory 4.2.4.1 SOFTINFO.TXT File The SOFTINFO.TXT file contains a description of the contents of the SOFTWARE directory. This is an ASCII file with record lengths no longer than 80 bytes. Each line is terminated with a carriage-return (ASCII 13) line-feed (ASCII 10) pair. The file has an attached PDS label of the form shown in Figure 4-1-1. 4.2.4.2 SOURCE Subdirectory The SOURCE subdirectory includes a Unix-style Makefile for compiling source code and several directories containing the code itself. These subdirectories include GVDR (software for parsing the GVDR files), LIBML (software for interfacing with MATLAB), PROJ (USGS map projection library software), and REGEX (source code for the GNU regular expression library). Subdirectory DISTRIB contains several of the software archives in compressed formats; specifics are included in SOFTINFO.TXT. MATLAB is a computational and graphics package distributed by The Math Works Inc., 24 Prime Park Way, Natick, MA 01760; the routines in LIBML were developed at Stanford. Source code in all directories is written in standard ANSI C. 4.2.4.3 SUN4 Subdirectory The SUN4 subdirectory contains compiled programs for a Sun SPARC Station running SunOS 4.1.2. These programs include GVPTEST (which repeatedly queries the user for a pair of pixel coordinates, reads the appropriate pixel from the GVDR files, and prints out the contents) and GVP2MAT (which extracts information on a region of pixels and stores the results in a format which can be ingested by MATLAB). 4.2.4.4 DECMIPS Subdirectory The DECMIPS subdirectory contains compiled programs for a MIPS- based DecStation running Ultrix 4.2a. The programs include GVPTEST (which repeatedly queries the user for a pair of pixel coordinates, reads the appropriate pixel from the GVDR files, and prints out the contents) and GVP2MAT (which extracts information on a region of pixels and stores the results in a format which can be ingested by MATLAB). 4.3 GVDR Directory (Data Directories) GVDR volumes include data directories for each of four separate map projections (Figure 3-1). The projections are sinusoidal equal area (SINU directory), Mercator (MERC directory), and polar stereographic (NORTH and SOUTH directories for the north and south polar regions, respectively). Each data directory contains the actual results of the GVDR compilation for that projection. Each directory contains a collection of binary tables, tables of footprint information, and accompanying detached labels and structure specifications (Figure 4-3). The names of the data files are the same for each projection, but the contents differ. The tables and their contents are described in Table 4-3. Each data file is accompanied by a detached PDS label, which describes the format of the file completely. Data tables have file names ending in .TAB; the corresponding PDS label has the same name except that .TAB is replaced by .LBL. In most cases the structure is given by a separate file with a name ending in .FMT. Examples of labels and structure files are included in Appendix A. Detached labels completely describe the corresponding data file. Labels are ASCII files with record lengths of 80 bytes. Structure files are also ASCII files with record lengths of 80 bytes. Each record in a label or structure file ends with a carriage-return (ASCII 13) line-feed (ASCII 10) pair. Keywords are defined in [3]. |================================================================| | | | Figure 4-3 Example GVDR Data Directory Structure | | | |================================================================| | | | root | | | | | |- GVDR | | | | | |- SINU (or MERC, or NORTH, or SOUTH) | | | | | |------------------------------------ | | | | | | | |- GVADF.LBL |- GVADF.FMT |- GVADF.TAB | | |- GVANF.LBL |- GVANF.FMT |- GVANF.TAB | | |- GVGEO.LBL |- GVGEO.FMT |- GVGEO.TAB | | |- GVHDR.LBL |- GVHDR.FMT |- GVHDR.TAB | | |- GVORB.LBL |- GVORB.FMT |- GVORB.TAB | | |- GVPIDX.LBL |- GVPIDX.FMT |- GVPIDX.TAB | | |- GVRDF.LBL |- GVRDF.FMT |- GVRDF.TAB | | |- GVTGEOM.LBL |- GVTGEOM.FMT |- GVTGEOM.TAB | | |- GVTIDX.LBL |- GVTIDX.FMT |- GVTIDX.TAB | | |- GVXIF.LBL |- GVXIF.FMT |- GVXIF.TAB | | |- GVNFF.FMT | | | |================================================================| |======================================================================| | | | Table 4-3 GVDR Data Files | | | |======================================================================| | Label | Structure | Data | Data File | | File Name | File Name | File Name | Contents Summary | |-------------+-------------+-------------+----------------------------| | GVHDR.LBL | GVHDR.FMT | GVHDR.TAB |Summary information for data| | | | |in this GVDR projection. | |-------------+-------------+-------------+----------------------------| | GVTIDX.LBL | GVTIDX.FMT | GVTIDX.TAB |Tile index, containing | | | | |coarse (tile) pointers to | | | | |actual data in other .TAB | | | | |files. | |-------------+-------------+-------------+----------------------------| | GVPIDX.LBL | GVPIDX.FMT | GVPIDX.TAB |Pixel index, containing fine| | | | |(pixel-level) pointers to | | | | |actual data in other .TAB | | | | |files. | |-------------+-------------+-------------+----------------------------| | GVADF.LBL | GVADF.FMT | GVADF.TAB |Radius and estimates of sur-| | | | |face properties (reflectivi-| | | | |ty and rms roughness) from | | | | |template fitting to Hagfors | | | | |functions at MIT (ARCDR | | | | |data). | |-------------+-------------+-------------+----------------------------| | GVANF.LBL | GVANF.FMT | GVANF.TAB |Estimates of surface proper-| | | GVNFF.FMT | |ties from Stanford linear | | | | |inversion. Includes experi-| | | | |mentally derived specific | | | | |radar cross section, and | | | | |results of fits to those | | | | |curves. | |-------------+-------------+-------------+----------------------------| | GVRDF.LBL | GVRDF.FMT | GVRDF.TAB |Thermal emissivity results | | | | |from MIT radiometry analysis| |-------------+-------------+-------------+----------------------------| | GVXIF.LBL | GVXIF.FMT | GVXIF.TAB |Measures of surface scatter-| | | | |at oblique angles from SAR | | | | |image data. Also includes | | | | |statistics on pixel values. | |-------------+-------------+-------------+----------------------------| | GVGEO.LBL | GVGEO.FMT | GVGEO.TAB |Coordinates for named geo- | | | | |logic features. Comparable | | | | |to GEO.TAB files on other | | | | |Magellan archival products. | |-------------+-------------+-------------+----------------------------| | GVORB.LBL | GVORB.FMT | GVORB.TAB |Record of source files for | | | | |data in this GVDR projection| |-------------+-------------+-------------+----------------------------| | GVTGEOM.LBL | GVTGEOM.FMT | GVTGEOM.TAB |Latitude and longitude of | | | | |GVDR tile corners. | |======================================================================| 5 Support Staff and Cognizant Personnel The following persons may be contacted for information. Michael J. Maurer Durand Building - Room 232 Center for Radar Astronomy Stanford University Stanford, CA 94305-4055 Phone: 415-723-1024 FAX: 415-723-9251 Electronic mail: maurer@nova.stanford.edu Richard A. Simpson Durand Building - Room 232 Center for Radar Astronomy Stanford University Stanford, CA 94305-4055 Phone: 415-723-3525 FAX: 415-723-9251 Electronic mail: rsimpson@magellan.stanford.edu G. Leonard Tyler Durand Building - Room 232 Center for Radar Astronomy Stanford University Stanford, CA 94305-4055 Phone: 415-723-3535 FAX: 415-723-9251 Electronic mail: len@nova.stanford.edu Planetary Data System: PDS Operator MS 525/3610 Jet Propulsion Laboratory 4800 Oak Grove Drive Pasadena, CA 91109 Phone: 818-306-6130 Electronic mail: JPLPDS::PDS_OPERATOR pds_operator@jplpds.jpl.nasa.gov Appendix A Example PDS Labels and Structure Definitions A.1 GVADF.FMT Example File DESCRIPTION = "This file describes the format of the TABLE in the GVADF.TAB file. See the GVADF.LBL file for the full PDS label." OBJECT = COLUMN NAME = SAMPLE_COUNT DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 1 BYTES = 2 DESCRIPTION = "The total number of ARCDRCD ADF footprints used to compute the estimates of radar scattering properties given in this row of the table. The quantities given in later columns pertain only these footprints. Any altimetry footprint that is partially or completely contained inside this pixel is included. (Only the small inner portion of altimetry footprints is considered for inclusion; this is the portion described by the ARCDRCD ADF fields ALT_ALONG_TRACK_FOOTPRINT_SIZE (alias AR_XFOOT) and ALT_CROSS_TRACK_FOOTPRINT_SIZE (alias AR_YFOOT). This does not include altimetry footprints that illuminated this pixel but did not do so from directly above.)" END_OBJECT = COLUMN OBJECT = COLUMN NAME = RADIUS_MEAN DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 3 BYTES = 2 OFFSET = 6040 SCALING_FACTOR = 0.000457806 UNIT = KM VALID_MINIMUM = 6040 VALID_MAXIMUM = 6070 DESCRIPTION = "The mean planetary radius of all the footprints used in this row. The radius is obtained from the DERIVED_PLANETARY_RADIUS field (alias AR_RADIUS) in the ARCDRCD." END_OBJECT = COLUMN OBJECT = COLUMN NAME = RADIUS_VARIANCE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 5 BYTES = 2 OFFSET = 0 SCALING_FACTOR = 7.63009e-05 UNIT = KM_SQUARED VALID_MINIMUM = 0 VALID_MAXIMUM = 5 DESCRIPTION = "The unbiased estimate of the variance of the planetary radius of all of the footprints used in this row. The radius is obtained from the DERIVED_PLANETARY_RADIUS field (alias AR_RADIUS) in the ARCDRCD. The variance estimate gives an indication of the topographic relief across the pixel. The unbiased estimate is obtained from the following formula: RADIUS_VARIANCE = 1/(N-1) * ( SUM(X_i^2) - 1/N * [SUM(X_i)]^2 ) where N = SAMPLE_COUNT above X_i = samples of radius AR_RADIUS, i = 1,2,...,N." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SLOPE_MEAN DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 7 BYTES = 1 OFFSET = 0 SCALING_FACTOR = 0.06 UNIT = DEGREE VALID_MINIMUM = 0 VALID_MAXIMUM = 15 DESCRIPTION = "The mean surface rms slope of the footprints used in this row. The rms slope is obtained from the RADAR_DERIVED_SURF_ROUGHNESS field (alias AR_SLOPE) in the ARCDRCD, and is based on the Hagfors model of rough surface scattering." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SLOPE_VARIANCE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 8 BYTES = 1 OFFSET = -3 SCALING_FACTOR = 0.02 UNIT = "N/A" /* see DESCRIPTION */ VALID_MINIMUM = 0.001 VALID_MAXIMUM = 100 DESCRIPTION = "The unbiased estimate of the variance of the rms slope of all of the footprints used in this row. The rms slope is obtained from the RADAR_DERIVED_SURF_ROUGHNESS field (alias AR_SLOPE) in the ARCDRCD, and is based on the Hagfors model of rough surface scattering. The variance estimate gives an indication of the surface roughness variability across the pixel. The unbiased estimate is obtained from the following formula: SLOPE_VARIANCE = 1/(N-1) * ( SUM(X_i^2) - 1/N * [SUM(X_i)]^2 ) where N = SAMPLE_COUNT above X_i = samples of slope AR_SLOPE, i = 1,2,...,N. The units of this measurement are degrees-squared, but the value stored in the table is the base-10 logarithm of the true value. To obtain the true value, apply the scaling and offset given above and raise 10 to this power." END_OBJECT = COLUMN OBJECT = COLUMN NAME = REFLECTIVITY_MEAN DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 9 BYTES = 1 OFFSET = -2.5 SCALING_FACTOR = 0.01 UNIT = "N/A" /* see DESCRIPTION */ VALID_MINIMUM = 0.00316228 VALID_MAXIMUM = 1 DESCRIPTION = "The mean surface bulk reflectivity of the footprints used in this row. The bulk reflectivity is obtained from the DERIVED_FRESNEL_REFLECTIVITY field (alias AR_RHO) in the ARCDRCD, and is based on the Hagfors model of rough surface scattering. The value has not been adjusted by the diffuse scattering correction term DERIVED_FRESNEL_REFLECT_CORR (alias AR_RHOCOR). The units of this measurement are dimensionless, but the value stored in the table is the base-10 logarithm of the true value. To obtain the true value, apply the scaling and offset given above and raise 10 to this power." END_OBJECT = COLUMN OBJECT = COLUMN NAME = REFLECTIVITY_VARIANCE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 10 BYTES = 1 OFFSET = -7 SCALING_FACTOR = 0.028 UNIT = "N/A" /* see DESCRIPTION */ VALID_MINIMUM = 0.000000100 VALID_MAXIMUM = 1 DESCRIPTION = "The unbiased estimate of the variance of the surface bulk reflectivity of the footprints used in this row. The bulk reflectivity is obtained from the DERIVED_FRESNEL_REFLECTIVITY field (alias AR_RHO) in the ARCDRCD, and is based on the Hagfors model of rough surface scattering. The value has not been corrected with the diffuse scattering correction term DERIVED_FRESNEL_REFLECT_CORR (alias AR_RHOCOR). The variance estimate gives an indication of the surface reflectivity variability across the pixel. The unbiased estimate is obtained from the following formula: REFLECTIVITY_VARIANCE = 1/(N-1) * ( SUM(X_i^2) - 1/N * [SUM(X_i)]^2 ) where N = SAMPLE_COUNT above X_i = samples of slope AR_RHO, i = 1,2,...,N. The units of this measurement are dimensionless, but the value stored in the table is the base-10 logarithm of the true value. To obtain the true value, apply the scaling and offset given above and raise 10 to this power." END_OBJECT = COLUMN A.2 GVADF.LBL Example File PDS_VERSION_ID = PDS3 /* File characteristics */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 10 FILE_RECORDS = 1898319 /* Data object pointer */ ^TABLE = "GVADF.TAB" /* Identification data elements */ DATA_SET_ID = "MGN-V-RDRS-5-GVDR-V1.0" DATA_SET_NAME = "MAGELLAN VENUS RADAR SYSTEM GLOBAL DATA RECORD V1.0" PRODUCT_ID = "GVADF-MERC.100" MISSION_NAME = "MAGELLAN" SPACECRAFT_NAME = "MAGELLAN" INSTRUMENT_NAME = "RADAR SYSTEM" TARGET_NAME = "VENUS" ORBIT_START_NUMBER = 376 ORBIT_STOP_NUMBER = 5747 START_TIME = "N/A" STOP_TIME = "N/A" SPACECRAFT_CLOCK_START_COUNT = "N/A" SPACECRAFT_CLOCK_STOP_COUNT = "N/A" PRODUCT_CREATION_TIME = 1994-05-10T22:21:59.000 PRODUCT_RELEASE_DATE = 1994-05-13 PRODUCT_SEQUENCE_NUMBER = 00000 PRODUCT_VERSION_TYPE = "PRELIMINARY" SOURCE_DATA_SET_ID = {"MGN-V-RDRS-CDR-ALT/RAD-V1.0"} SOURCE_PRODUCT_ID = {"ARCDRCD.001;2","ARCDRCD.002;1", "ARCDRCD.003;1","ARCDRCD.004;1","ARCDRCD.005;1","ARCDRCD.006;1", "ARCDRCD.007;1","ARCDRCD.008;1","ARCDRCD.009;1","ARCDRCD.010;1", "ARCDRCD.011;1","ARCDRCD.012;1","ARCDRCD.013;1","ARCDRCD.014;1", "ARCDRCD.015;1","ARCDRCD.016;1","ARCDRCD.017;1","ARCDRCD.018;1", "ARCDRCD.019;1"} SOFTWARE_FLAG = "Y" PRODUCER_FULL_NAME = "Michael J. Maurer" PRODUCER_INSTITUTION_NAME = "Stanford Center for Radar Astronomy" PRODUCER_ID = "SCRA" DESCRIPTION = "The GVADF file contains estimates of the planetary radius and large-scale surface statistics derived from the altimeter echoes by a template-fitting procedure. (The ADF acronym stands for 'Altimetry Data File', one of the data files in the ARCDR data product.) This file is a table; each row in the table summarizes ADF results in a particular altimetry viewing geometry. The location and number of rows associated with each pixel are given by the corresponding values of ADF_START and ADF_SAMPLES in GVPIDX.TAB. See the descriptions in the GVTIDX.LBL and GVPIDX.LBL files for the overall organization of the GVDR. These files describe the division of the planet into pixels and organization of pixels into rectangular tiles." /* Data object definitions */ OBJECT = TABLE INTERCHANGE_FORMAT = BINARY ROWS = 1898319 COLUMNS = 7 ROW_BYTES = 10 ^STRUCTURE = "GVADF.FMT" END_OBJECT = TABLE END A.3 GVANF.FMT Example File DESCRIPTION = "This file describes the format of the TABLE in the GVANF.TAB file. See the GVANF.LBL file for the full PDS label." OBJECT = COLUMN NAME = RECLEN /* unused */ DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 1 BYTES = 2 DESCRIPTION = "This field will removed in the final product. It is unused in this version." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SAMPLE_COUNT DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 3 BYTES = 2 DESCRIPTION = "The total number of SCVDR ANF altimeter footprints used to compute the estimates of radar scattering properties given in this row of the table. The quantities given in later columns pertain only these footprints. Any altimeter footprint that is partially or completely contained inside this pixel is included. The distance from pixel center to footprint center is used to weight the averaging process. The extent of the altimeter footprint is defined by the first-order range-aliasing and frequency-aliasing points, or the antenna pattern's 3 dB beamwidth, whichever is smaller. Note that this is much larger than the definition used for the ARCDRCD ADF files, and near the poles results in each footprint overlapping hundreds of GVDR pixels." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SCATTERING_ANGLE_COUNT DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 5 BYTES = 1 VALID_MINIMUM = 0 VALID_MAXIMUM = 21 DESCRIPTION = "The number of scattering angles for which estimates of scattering cross-section are given below in the object CROSS_SECTION_CONTAINER. The maximum scattering angle is limited by geometric factors, and decreases toward the poles. Only the first SCATTERING_ANGLE_COUNT angles are valid." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SCATTERING_FIT_COUNT DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 6 BYTES = 1 VALID_MINIMUM = 0 VALID_MAXIMUM = 5 DESCRIPTION = "The number of analytic scattering models which have been fitted to the observed scattering law. Only the first SCATTERING_FIT_COUNT fits in SCATTERING_LAW_FITS_CONTAINER are valid." END_OBJECT = COLUMN OBJECT = COLUMN NAME = DOPPLER_CENTROID DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 7 BYTES = 2 OFFSET = -6000 SCALING_FACTOR = 0.183122 UNIT = HZ VALID_MINIMUM = -6000 VALID_MAXIMUM = 6000 DESCRIPTION = "The average observed centroid of the received altimetry echo spectrum." END_OBJECT = COLUMN OBJECT = COLUMN NAME = NADIR_TRACK_AZIMUTH_ANGLE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 9 BYTES = 1 OFFSET = 0 SCALING_FACTOR = 1.44 UNIT = DEGREE VALID_MINIMUM = 0 VALID_MAXIMUM = 360 DESCRIPTION = "The average azimuthal angle of the spacecraft nadir track. The nadir point is the point on the surface intersected by the line between the spacecraft and the center of the planet. The nadir track is the locus of that point as it moves along the surface. The surface is assumed to be perfectly spherical for the purposes of calculating the azimuthal angle. The azimuthal angle is defined in two ways, depending on the image map projection in use. For the Sinusoidal and Mercator map projections, the direction of the nadir track is expressed as a heading on a compass, in degrees clockwise from North. For example, if the nadir point is moving due east, the azimuthal angle is defined to be 90 degrees. Since this definition becomes useless near the poles, this field is set to zero above 85 degrees of latitude for the Sinusoidal projection. The Mercator projection does not extend to such high latitudes. For the Polar Stereographic map projection, the azimuth angle is expressed in the cartesian map coordinates rather than in geographic coordinates. This makes the azimuth angle more useful for interpretation because its meaning no longer varies with position. First, the azimuth direction is computed as above. Then, this direction is transformed to a direction in map coordinates; the transformed vector is parallel to the vector originating at the nadir point and pointing in the azimuth direction. This vector is expressed in degrees clockwise from the +Y (up) direction on the map. For example, if the north polar projection has 0 degrees of longitude at the bottom, then a footprint at 90 degrees of longitude with a true azimuth of 90 degrees (nadir point moving due east) has a transformed azimuth of 0 degrees. The nadir point appears to be moving in the +Y direction on the map. The relationship between true azimuth and transformed azimuth is simple. For the north polar projection with 0 degrees longitude at the bottom, CARTESIAN_AZIMUTH = GEOGRAPHIC_AZIMUTH - LONGITUDE and for the south polar projection with 0 degrees longitude at the top, CARTESIAN_AZIMUTH = GEOGRAPHIC_AZIMUTH + LONGITUDE As discussed in the GVHDR.LBL file, the group of altimetry observations used in this row forms a 'cohort'. Within a cohort, the azimuth angle of each observation falls within a single interval of size 360/N, where N is the value of ANF_COHORT_AZIMUTH_COUNT from the GVHDR file. We can reconstruct that interval by noting that the average azimuth angle of all the observations (given in this column) falls within the same interval. Specifically, we find a value of I that satisfies I * 360.0 / N <= AZIMUTH_ANGLE < (I+1) * 360.0 / N where N = ANF_COHORT_AZIMUTH_COUNT I = integer between 0 and N-1 inclusive The azimuth angles of all observations in the cohort lie in the interval [I*360 , (I+1)*360), and their average value is given in this column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = PAD DATA_TYPE = "N/A" START_BYTE = 10 BYTES = 1 DESCRIPTION = "This field will be removed in the final data product ad AZIMUTH_ANGLE will be increased to two bytes." END_OBJECT = COLUMN OBJECT = CONTAINER NAME = CROSS_SECTION_CONTAINER START_BYTE = 11 BYTES = 21 REPETITIONS = 21 DESCRIPTION = "A vector of specific radar cross section measurements, indexed by incidence angle. Only the first SCATTERING_ANGLE_COUNT elements of this vector are valid. The values were obtained by linear inversion of a discretized integral equation for scattering from a sphere." OBJECT = COLUMN NAME = SPECIFIC_RADAR_CROSS_SECTION DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 1 BYTES = 1 OFFSET = -3 SCALING_FACTOR = 0.024 UNIT = "N/A" /* see DESCRIPTION */ VALID_MINIMUM = 0.001 VALID_MAXIMUM = 1000 SAMPLING_PARAMETER_NAME = INCIDENCE_ANGLE SAMPLING_PARAMETER_UNIT = DEGREE SAMPLING_PARAMETER_INTERVAL = 0.5 MINIMUM_SAMPLING_PARAMETER = 0.25 MAXIMUM_SAMPLING_PARAMETER = 10.25 DESCRIPTION = "The observed specific radar cross-section at a given angle of incidence. The units of this measurement are dimensionless, meters-squared per meters-squared, and are recorded here logarithmically. To obtain the actual cross-section, apply the scaling and offset given above and raise 10 to this power." END_OBJECT = COLUMN END_OBJECT = CONTAINER OBJECT = CONTAINER NAME = CROSS_SECTION_VARIANCE_CONTAINER START_BYTE = 32 BYTES = 21 REPETITIONS = 21 DESCRIPTION = "A vector of the formal variance of the above specific radar cross section measurements, indexed by incidence angle. Only the first SCATTERING_ANGLE_COUNT elements of this vector are valid. The values were obtained by linear propagation of errors, based on physical estimates for the thermal and speckle noise in the received radio signal." OBJECT = COLUMN NAME = SPECIFIC_RADAR_CROSS_SECTION_VARIANCE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 1 BYTES = 1 OFFSET = -3 SCALING_FACTOR = 0.032 UNIT = "N/A" /* see DESCRIPTION */ VALID_MINIMUM = 0.001 VALID_MAXIMUM = 100000 SAMPLING_PARAMETER_NAME = INCIDENCE_ANGLE SAMPLING_PARAMETER_UNIT = DEGREE SAMPLING_PARAMETER_INTERVAL = 0.5 MINIMUM_SAMPLING_PARAMETER = 0.25 MAXIMUM_SAMPLING_PARAMETER = 10.25 DESCRIPTION = "The formal variance of the corresponding entry in the object SPECIFIC_RADAR_CROSS_SECTION. The units of this value are dimensionless, meters-fourth per meters-fourth, and are recorded here logarithmically. To obtain the actual variance, raise 10 to the value given here." END_OBJECT = COLUMN END_OBJECT = CONTAINER OBJECT = CONTAINER NAME = SCATTERING_LAW_FITS_CONTAINER START_BYTE = 53 BYTES = 50 REPETITIONS = 5 DESCRIPTION = "A collection of best fit scattering models to the observed scattering law in SPECIFIC_RADAR_CROSS_SECTION. The fits are made using the formal variance in the object SPECIFIC_RADAR_CROSS_SECTION_VARIANCE. Each repetition contains the results of a single least-squares fit of the empirical scattering function to a particular scattering model." ^STRUCTURE = "GVNFF.FMT" END_OBJECT = CONTAINER A.4 GVANF.LBL Example File PDS_VERSION_ID = PDS3 /* File characteristics */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 102 FILE_RECORDS = 1945809 /* Data object pointer */ ^TABLE = "GVANF.TAB" /* Identification data elements */ DATA_SET_ID = "MGN-V-RDRS-5-GVDR-V1.0" DATA_SET_NAME = "MAGELLAN VENUS RADAR SYSTEM GLOBAL DATA RECORD V1.0" PRODUCT_ID = "GVANF-MERC.100" MISSION_NAME = "MAGELLAN" SPACECRAFT_NAME = "MAGELLAN" INSTRUMENT_NAME = "RADAR SYSTEM" TARGET_NAME = "VENUS" ORBIT_START_NUMBER = 376 ORBIT_STOP_NUMBER = 2599 START_TIME = "N/A" STOP_TIME = "N/A" SPACECRAFT_CLOCK_START_COUNT = "N/A" SPACECRAFT_CLOCK_STOP_COUNT = "N/A" PRODUCT_CREATION_TIME = 1994-05-10T22:22:00.000 PRODUCT_RELEASE_DATE = 1994-05-13 PRODUCT_SEQUENCE_NUMBER = 00000 PRODUCT_VERSION_TYPE = "PRELIMINARY" SOURCE_DATA_SET_ID = {"MGN-V-RDRS-5-SCVDR-V1.0"} SOURCE_PRODUCT_ID = {"SCVDR.00376-00399.1", "SCVDR.00400-00499.1","SCVDR.01100-01199.1","SCVDR.01200-01299.1", "SCVDR.01300-01399.1","SCVDR.01400-01499.1","SCVDR.01500-01599.1", "SCVDR.01600-01699.1","SCVDR.01700-01799.1","SCVDR.01800-01899.1", "SCVDR.01900-01999.1","SCVDR.02000-02099.1","SCVDR.02100-02199.1", "SCVDR.00500-00599.2","SCVDR.00600-00676.2","SCVDR.00787-00799.2", "SCVDR.00800-00899.2","SCVDR.00900-00999.2","SCVDR.01000-01099.2", "SCVDR.02200-02299.2","SCVDR.02400-02499.2","SCVDR.02500-02599.2", "SCVDR.02300-02399.1"} SOFTWARE_FLAG = "Y" PRODUCER_FULL_NAME = "Michael J. Maurer" PRODUCER_INSTITUTION_NAME = "Stanford Center for Radar Astronomy" PRODUCER_ID = "SCRA" DESCRIPTION = "The GVANF file contains estimates of the large-scale surface statistics derived from the altimeter echoes by a linear inversion procedure. (The ANF acronym stands for 'Altimetry iNversion File', one of the data files in the SCVDR data product.) This file also contains least-square fits of certain scattering models to the empirical scattering function produced by the inversion procedure. This file is a table; each row in the table summarizes ANF results in a particular altimetry viewing geometry. The location and number of rows associated with each pixel are given by the corresponding values of ANF_START and ANF_SAMPLES in GVPIDX.TAB. See the descriptions in the GVTIDX.LBL and GVPIDX.LBL files for the overall organization of the GVDR. These files describe the division of the planet into pixels and organization of pixels into rectangular tiles." /* Data object definitions */ OBJECT = TABLE INTERCHANGE_FORMAT = BINARY ROWS = 1945809 COLUMNS = 98 ROW_BYTES = 102 ^STRUCTURE = "GVANF.FMT" END_OBJECT = TABLE END A.5 GVGEO.FMT Example File DESCRIPTION = "This file describes the format of the TABLE in the GVGEO.TAB file. See the GVGEO.LBL file for the full PDS label. Some of the DESCRIPTION fields in this label have been copied verbatim from the Magellan project GEO.TAB file provided on the MIDR CD-ROM volumes." OBJECT = COLUMN NAME = FEATURE_TYPE DATA_TYPE = CHARACTER START_BYTE = 2 BYTES = 20 DESCRIPTION = "Official IAU designation for type of feature. Examples are (with plurals in parentheses): ARACHNOID FLOW PLANUM (PLANA) CALDERA FOSSA (FOSSAE) REGIO (REGIONES) CHASMA (CHASMATA) LINEA RUPES COLLIS (COLLES) LINEAMENT TERRA (TERRAE) CORONA (CORONAE) MONS (MONTES) TESSERA (TESSERAE) CRATER OVOID THOLUS (THOLI) DOME PATERA (PATERAE) DORSUM (DORSA) PLANITIA (PLANITIAE)" END_OBJECT = COLUMN OBJECT = COLUMN NAME = SEARCH_FEATURE_NAME DATA_TYPE = CHARACTER START_BYTE = 25 BYTES = 40 DESCRIPTION = "The geographical feature name with all diacritical marks and punctuation stripped off. This name uses only uppercase ASCII alphabetic characters and can be used for sorting and searching since it is unique within this table. When printing the name, the diacritic_feature_name should be used instead." END_OBJECT = COLUMN OBJECT = COLUMN NAME = DIACRITIC_FEATURE_NAME DATA_TYPE = CHARACTER START_BYTE = 68 BYTES = 40 DESCRIPTION = "The geographical feature name containing standard diacritical information. Contains upper and lower case letters. The name with the diacritical marks should be used when printing the feature name. DIACRITICALS USED IN THE TABLE The word diacritic comes from a Greek word meaning to separate. It refers to the accent marks employed to separate, or distinguish, one form of pronunciation of a vowel or consonant from another. This note is included to familiarize the user with the codes used to represent diacriticals found in the table, and the values usually associated with them. In the table, the code for a diacritical is preceded by a backslash and is followed, without a space, by the letter it is modifying. This note is organized as follows: the code is listed first, followed by the name of the accent mark, if applicable, a brief description of the appearance of the diacritical and a short narrative on its usage. \% acute accent; a straight diagonal line extending from upper right to lower left. The acute accent is used in most languages to lengthen a vowel; in some, such as Oscan, to denote an open vowel. The acute is also often used to indicate the stressed syllable; in some transcriptions it indicates a palatalized consonant. \: diaeresis or umlaut; two dots surmounting the letter. In Romance languages and English, the diaeresis is used to indicate that consecutive vowels do not form a diphthong (see below); in modern German and Scandinavian languages, it denotes palatalization of vowels. \^ circumflex; a chevron or inverted 'v' shape, with the apex at the top. Used most often in modern languages to indicate lengthening of a vowel. \~ tilde; a curving or waving line above the letter. The tilde is a form of circumflex. The tilde is used most often in Spanish to form a palatalized n as in the word 'ano', pronounced 'anyo'. It is also used occasionally to indicate nasalized vowels. \- macron; a straight line above the letter. The macron is used almost universally to lengthen a vowel. \u breve; a concave semicircle or 'u' shape surmounting the letter. Originally used in Greek, the breve indicates a short vowel. \o a small circle or 'o' above the letter. Frequently used in Scandinavian languages to indicate a broad 'o'. \ae diphthong or ligature; transcribed as two letters in contact with each other. The diphthong is a combination of vowels that are pronounced together. \, cedilla; a curved line surmounted by a vertical line, placed at the bottom of the letter. The cedilla is used in Spanish and French to denote a dental, or soft, 'c'. In the new Turkish transcription, 'c' cedilla has the value of English 'ch'. In Semitic languages, the cedilla under a consonant indicates that it is emphatic. \v check or inverted circumflex; a 'v' shape above the letter. This accent is used widely in Slavic languages to indicate a palatal articulation, like the consonant sounds in the English words chapter and shoe and the 'zh' sound in pleasure. \. a single dot above the letter. This diacritical denotes various things; in Lithuanian, it indicates a close long vowel. In Sanskrit, when used with 'n', it is a velar sound, as in the English 'sink'; in Irish orthography, it indicates a fricative consonant (see below). \' accent grave; a diagonal line (above the letter) extending from upper left to lower right. The grave accent is used in French, Spanish and Italian to denote open vowels. \_ fricative; a horizontal line through a consonant. A fricative consonant is characterized by a frictional rustling of the breath as it is emitted. Sources: Webster's New Collegiate Dictionary, G.& C. Merriam Co. Springfield, Mass., and Collier's Encyclopedia, P.F. Collier, Inc., London and New York " END_OBJECT = COLUMN OBJECT = COLUMN NAME = FEATURE_STATUS_TYPE DATA_TYPE = CHARACTER START_BYTE = 111 BYTES = 15 DESCRIPTION = "The IAU approval status of the named feature. Permitted values are 'PROPOSED', 'PROVISIONAL', 'IAU-APPROVED', and 'DROPPED'. This table contains only 'IAU-APPROVED' and 'PROVISIONAL' names." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_LEFT_LONGITUDE DATA_TYPE = ASCII_REAL START_BYTE = 128 BYTES = 6 VALID_MINIMUM = -180 VALID_MAXIMUM = 360 UNIT = DEGREE DESCRIPTION = "The longitude of the top-left corner of the feature bounding box. The top-left corner has the minimum longitude value and the maximum latitude value." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_LEFT_LATITUDE DATA_TYPE = ASCII_REAL START_BYTE = 135 BYTES = 6 VALID_MINIMUM = -90 VALID_MAXIMUM = 90 UNIT = DEGREE DESCRIPTION = "The latitude of the top-left corner of the feature bounding box. The top-left corner has the minimum longitude value and the maximum latitude value." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_LEFT_IMAGE_COORD_X DATA_TYPE = ASCII_INTEGER START_BYTE = 142 BYTES = 6 DESCRIPTION = "The image pixel x-coordinate of the top-left corner of the feature bounding box. The top-left corner has the minimum longitude value and the maximum latitude value. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_LEFT_IMAGE_COORD_Y DATA_TYPE = ASCII_INTEGER START_BYTE = 149 BYTES = 6 DESCRIPTION = "The image pixel y-coordinate of the top-left corner of the feature bounding box. The top-left corner has the minimum longitude value and the maximum latitude value. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_LEFT_TILE_COORD_X DATA_TYPE = ASCII_INTEGER START_BYTE = 156 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 65 DESCRIPTION = "The tile x-coordinate of the top-left corner of the feature bounding box. The top-left corner has the minimum longitude value and the maximum latitude value. This column gives the coordinate of the tile that contains this image pixel; an additional pixel coordinate within the tile is needed to specify the pixel completely. The tile/pixel coordinates are related to the image pixel coordinates by the tiling information in the GVHDR file. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file. If the image coordinates do not lie within the extents of the GVDR image, this column will contain the value -1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_LEFT_TILE_COORD_Y DATA_TYPE = ASCII_INTEGER START_BYTE = 161 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 31 DESCRIPTION = "The tile y-coordinate of the top-left corner of the feature bounding box. The top-left corner has the minimum longitude value and the maximum latitude value. This column gives the coordinate of the tile that contains this image pixel; an additional pixel coordinate within the tile is needed to specify the pixel completely. The tile/pixel coordinates are related to the image pixel coordinates by the tiling information in the GVHDR file. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file. If the image coordinates do not lie within the extents of the GVDR image, this column will contain the value -1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_LEFT_PIXEL_COORD_X DATA_TYPE = ASCII_INTEGER START_BYTE = 166 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 31 DESCRIPTION = "The pixel x-coordinate (within a tile) of the top-left corner of the feature bounding box. The top-left corner has the minimum longitude value and the maximum latitude value. This column gives the coordinate of the pixel within the tile that contains this image pixel. The tile/pixel coordinates are related to the image pixel coordinates by the tiling information in the GVHDR file. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file. If the image coordinates do not lie within the extents of the GVDR image, this column will contain the value -1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_LEFT_PIXEL_COORD_Y DATA_TYPE = ASCII_INTEGER START_BYTE = 171 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 31 DESCRIPTION = "The pixel y-coordinate (within a tile) of the top-left corner of the feature bounding box. The top-left corner has the minimum longitude value and the maximum latitude value. This column gives the coordinate of the pixel within the tile that contains this image pixel. The tile/pixel coordinates are related to the image pixel coordinates by the tiling information in the GVHDR file. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file. If the image coordinates do not lie within the extents of the GVDR image, this column will contain the value -1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_RIGHT_LONGITUDE DATA_TYPE = ASCII_REAL START_BYTE = 176 BYTES = 6 VALID_MINIMUM = -180 VALID_MAXIMUM = 360 UNIT = DEGREE DESCRIPTION = "The longitude of the top-right corner of the feature bounding box. The top-right corner has the maximum longitude value and the maximum latitude value." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_RIGHT_LATITUDE DATA_TYPE = ASCII_REAL START_BYTE = 183 BYTES = 6 VALID_MINIMUM = -90 VALID_MAXIMUM = 90 UNIT = DEGREE DESCRIPTION = "The latitude of the top-right corner of the feature bounding box. The top-right corner has the maximum longitude value and the maximum latitude value." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_RIGHT_IMAGE_COORD_X DATA_TYPE = ASCII_INTEGER START_BYTE = 190 BYTES = 6 DESCRIPTION = "The image pixel x-coordinate of the top-right corner of the feature bounding box. The top-right corner has the maximum longitude value and the maximum latitude value. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_RIGHT_IMAGE_COORD_Y DATA_TYPE = ASCII_INTEGER START_BYTE = 197 BYTES = 6 DESCRIPTION = "The image pixel y-coordinate of the top-right corner of the feature bounding box. The top-right corner has the maximum longitude value and the maximum latitude value. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_RIGHT_TILE_COORD_X DATA_TYPE = ASCII_INTEGER START_BYTE = 204 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 65 DESCRIPTION = "The tile x-coordinate of the top-right corner of the feature bounding box. The top-right corner has the maximum longitude value and the maximum latitude value. This column gives the coordinate of the tile that contains this image pixel; an additional pixel coordinate within the tile is needed to specify the pixel completely. The tile/pixel coordinates are related to the image pixel coordinates by the tiling information in the GVHDR file. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file. If the image coordinates do not lie within the extents of the GVDR image, this column will contain the value -1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_RIGHT_TILE_COORD_Y DATA_TYPE = ASCII_INTEGER START_BYTE = 209 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 31 DESCRIPTION = "The tile y-coordinate of the top-right corner of the feature bounding box. The top-right corner has the maximum longitude value and the maximum latitude value. This column gives the coordinate of the tile that contains this image pixel; an additional pixel coordinate within the tile is needed to specify the pixel completely. The tile/pixel coordinates are related to the image pixel coordinates by the tiling information in the GVHDR file. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file. If the image coordinates do not lie within the extents of the GVDR image, this column will contain the value -1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_RIGHT_PIXEL_COORD_X DATA_TYPE = ASCII_INTEGER START_BYTE = 214 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 31 DESCRIPTION = "The pixel x-coordinate (within a tile) of the top-right corner of the feature bounding box. The top-right corner has the maximum longitude value and the maximum latitude value. This column gives the coordinate of the pixel within the tile that contains this image pixel. The tile/pixel coordinates are related to the image pixel coordinates by the tiling information in the GVHDR file. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file. If the image coordinates do not lie within the extents of the GVDR image, this column will contain the value -1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_RIGHT_PIXEL_COORD_Y DATA_TYPE = ASCII_INTEGER START_BYTE = 219 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 31 DESCRIPTION = "The pixel y-coordinate (within a tile) of the top-right corner of the feature bounding box. The top-right corner has the maximum longitude value and the maximum latitude value. This column gives the coordinate of the pixel within the tile that contains this image pixel. The tile/pixel coordinates are related to the image pixel coordinates by the tiling information in the GVHDR file. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file. If the image coordinates do not lie within the extents of the GVDR image, this column will contain the value -1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_LEFT_LONGITUDE DATA_TYPE = ASCII_REAL START_BYTE = 224 BYTES = 6 VALID_MINIMUM = -180 VALID_MAXIMUM = 360 UNIT = DEGREE DESCRIPTION = "The longitude of the bottom-left corner of the feature bounding box. The bottom-left corner has the minimum longitude value and the minimum latitude value." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_LEFT_LATITUDE DATA_TYPE = ASCII_REAL START_BYTE = 231 BYTES = 6 VALID_MINIMUM = -90 VALID_MAXIMUM = 90 UNIT = DEGREE DESCRIPTION = "The latitude of the bottom-left corner of the feature bounding box. The bottom-left corner has the minimum longitude value and the minimum latitude value." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_LEFT_IMAGE_COORD_X DATA_TYPE = ASCII_INTEGER START_BYTE = 238 BYTES = 6 DESCRIPTION = "The image pixel x-coordinate of the bottom-left corner of the feature bounding box. The bottom-left corner has the minimum longitude value and the minimum latitude value. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_LEFT_IMAGE_COORD_Y DATA_TYPE = ASCII_INTEGER START_BYTE = 245 BYTES = 6 DESCRIPTION = "The image pixel y-coordinate of the bottom-left corner of the feature bounding box. The bottom-left corner has the minimum longitude value and the minimum latitude value. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_LEFT_TILE_COORD_X DATA_TYPE = ASCII_INTEGER START_BYTE = 252 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 65 DESCRIPTION = "The tile x-coordinate of the bottom-left corner of the feature bounding box. The bottom-left corner has the minimum longitude value and the minimum latitude value. This column gives the coordinate of the tile that contains this image pixel; an additional pixel coordinate within the tile is needed to specify the pixel completely. The tile/pixel coordinates are related to the image pixel coordinates by the tiling information in the GVHDR file. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file. If the image coordinates do not lie within the extents of the GVDR image, this column will contain the value -1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_LEFT_TILE_COORD_Y DATA_TYPE = ASCII_INTEGER START_BYTE = 257 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 31 DESCRIPTION = "The tile y-coordinate of the bottom-left corner of the feature bounding box. The bottom-left corner has the minimum longitude value and the minimum latitude value. This column gives the coordinate of the tile that contains this image pixel; an additional pixel coordinate within the tile is needed to specify the pixel completely. The tile/pixel coordinates are related to the image pixel coordinates by the tiling information in the GVHDR file. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file. If the image coordinates do not lie within the extents of the GVDR image, this column will contain the value -1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_LEFT_PIXEL_COORD_X DATA_TYPE = ASCII_INTEGER START_BYTE = 262 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 31 DESCRIPTION = "The pixel x-coordinate (within a tile) of the bottom-left corner of the feature bounding box. The bottom-left corner has the minimum longitude value and the minimum latitude value. This column gives the coordinate of the pixel within the tile that contains this image pixel. The tile/pixel coordinates are related to the image pixel coordinates by the tiling information in the GVHDR file. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file. If the image coordinates do not lie within the extents of the GVDR image, this column will contain the value -1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_LEFT_PIXEL_COORD_Y DATA_TYPE = ASCII_INTEGER START_BYTE = 267 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 31 DESCRIPTION = "The pixel y-coordinate (within a tile) of the bottom-left corner of the feature bounding box. The bottom-left corner has the minimum longitude value and the minimum latitude value. This column gives the coordinate of the pixel within the tile that contains this image pixel. The tile/pixel coordinates are related to the image pixel coordinates by the tiling information in the GVHDR file. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file. If the image coordinates do not lie within the extents of the GVDR image, this column will contain the value -1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_RIGHT_LONGITUDE DATA_TYPE = ASCII_REAL START_BYTE = 272 BYTES = 6 VALID_MINIMUM = -180 VALID_MAXIMUM = 360 UNIT = DEGREE DESCRIPTION = "The longitude of the bottom-right corner of the feature bounding box. The bottom-right corner has the maximum longitude value and the minimum latitude value." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_RIGHT_LATITUDE DATA_TYPE = ASCII_REAL START_BYTE = 279 BYTES = 6 VALID_MINIMUM = -90 VALID_MAXIMUM = 90 UNIT = DEGREE DESCRIPTION = "The latitude of the bottom-right corner of the feature bounding box. The bottom-right corner has the maximum longitude value and the minimum latitude value." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_RIGHT_IMAGE_COORD_X DATA_TYPE = ASCII_INTEGER START_BYTE = 286 BYTES = 6 DESCRIPTION = "The image pixel x-coordinate of the bottom-right corner of the feature bounding box. The bottom-right corner has the maximum longitude value and the minimum latitude value. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_RIGHT_IMAGE_COORD_Y DATA_TYPE = ASCII_INTEGER START_BYTE = 293 BYTES = 6 DESCRIPTION = "The image pixel y-coordinate of the bottom-right corner of the feature bounding box. The bottom-right corner has the maximum longitude value and the minimum latitude value. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_RIGHT_TILE_COORD_X DATA_TYPE = ASCII_INTEGER START_BYTE = 300 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 65 DESCRIPTION = "The tile x-coordinate of the bottom-right corner of the feature bounding box. The bottom-right corner has the maximum longitude value and the minimum latitude value. This column gives the coordinate of the tile that contains this image pixel; an additional pixel coordinate within the tile is needed to specify the pixel completely. The tile/pixel coordinates are related to the image pixel coordinates by the tiling information in the GVHDR file. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file. If the image coordinates do not lie within the extents of the GVDR image, this column will contain the value -1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_RIGHT_TILE_COORD_Y DATA_TYPE = ASCII_INTEGER START_BYTE = 305 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 31 DESCRIPTION = "The tile y-coordinate of the bottom-right corner of the feature bounding box. The bottom-right corner has the maximum longitude value and the minimum latitude value. This column gives the coordinate of the tile that contains this image pixel; an additional pixel coordinate within the tile is needed to specify the pixel completely. The tile/pixel coordinates are related to the image pixel coordinates by the tiling information in the GVHDR file. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file. If the image coordinates do not lie within the extents of the GVDR image, this column will contain the value -1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_RIGHT_PIXEL_COORD_X DATA_TYPE = ASCII_INTEGER START_BYTE = 310 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 31 DESCRIPTION = "The pixel x-coordinate (within a tile) of the bottom-right corner of the feature bounding box. The bottom-right corner has the maximum longitude value and the minimum latitude value. This column gives the coordinate of the pixel within the tile that contains this image pixel. The tile/pixel coordinates are related to the image pixel coordinates by the tiling information in the GVHDR file. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file. If the image coordinates do not lie within the extents of the GVDR image, this column will contain the value -1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_RIGHT_PIXEL_COORD_Y DATA_TYPE = ASCII_INTEGER START_BYTE = 315 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 31 DESCRIPTION = "The pixel y-coordinate (within a tile) of the bottom-right corner of the feature bounding box. The bottom-right corner has the maximum longitude value and the minimum latitude value. This column gives the coordinate of the pixel within the tile that contains this image pixel. The tile/pixel coordinates are related to the image pixel coordinates by the tiling information in the GVHDR file. The image pixel coordinates are related to geographic coordinates by the map projection defined by IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file. If the image coordinates do not lie within the extents of the GVDR image, this column will contain the value -1." END_OBJECT = COLUMN A.6 GVGEO.LBL Example File PDS_VERSION_ID = PDS3 /* File characteristics */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 320 FILE_RECORDS = 821 /* Data object pointer */ ^TABLE = "GVGEO.TAB" /* Identification data elements */ DATA_SET_ID = "MGN-V-RDRS-5-GVDR-V1.0" DATA_SET_NAME = "MAGELLAN VENUS RADAR SYSTEM GLOBAL DATA RECORD V1.0" PRODUCT_ID = "GVGEO-MERC.100" MISSION_NAME = "MAGELLAN" SPACECRAFT_NAME = "MAGELLAN" INSTRUMENT_NAME = "RADAR SYSTEM" TARGET_NAME = "VENUS" ORBIT_START_NUMBER = 376 ORBIT_STOP_NUMBER = 5747 START_TIME = "N/A" STOP_TIME = "N/A" SPACECRAFT_CLOCK_START_COUNT = "N/A" SPACECRAFT_CLOCK_STOP_COUNT = "N/A" PRODUCT_CREATION_TIME = 1994-05-10T22:21:38.000 PRODUCT_RELEASE_DATE = 1994-05-13 PRODUCT_SEQUENCE_NUMBER = 00000 PRODUCT_VERSION_TYPE = "PRELIMINARY" SOURCE_DATA_SET_ID = {"MGN-V-RDRS-5-SCVDR-V1.0", "MGN-V-RDRS-CDR-ALT/RAD-V1.0"} SOURCE_PRODUCT_ID = {"SCVDR.00376-00399.1", "SCVDR.00400-00499.1","SCVDR.01100-01199.1","SCVDR.01200-01299.1", "SCVDR.01300-01399.1","SCVDR.01400-01499.1","SCVDR.01500-01599.1", "SCVDR.01600-01699.1","SCVDR.01700-01799.1","SCVDR.01800-01899.1", "SCVDR.01900-01999.1","SCVDR.02000-02099.1","SCVDR.02100-02199.1", "SCVDR.00500-00599.2","SCVDR.00600-00676.2","SCVDR.00787-00799.2", "SCVDR.00800-00899.2","SCVDR.00900-00999.2","SCVDR.01000-01099.2", "SCVDR.02200-02299.2","SCVDR.02400-02499.2","SCVDR.02500-02599.2", "SCVDR.02300-02399.1","ARCDRCD.001;2","ARCDRCD.002;1","ARCDRCD.003;1", "ARCDRCD.004;1","ARCDRCD.005;1","ARCDRCD.006;1","ARCDRCD.007;1", "ARCDRCD.008;1","ARCDRCD.009;1","ARCDRCD.010;1","ARCDRCD.011;1", "ARCDRCD.012;1","ARCDRCD.013;1","ARCDRCD.014;1","ARCDRCD.015;1", "ARCDRCD.016;1","ARCDRCD.017;1","ARCDRCD.018;1","ARCDRCD.019;1"} SOFTWARE_FLAG = "Y" PRODUCER_FULL_NAME = "Michael J. Maurer" PRODUCER_INSTITUTION_NAME = "Stanford Center for Radar Astronomy" PRODUCER_ID = "SCRA" DESCRIPTION = "This file contains the geographic and cartesian coordinates for many named geologic features. Each feature has been assigned minimum and maximum longitude and latitude values by the Magellan project. These four values can be used to define a rectangular box in longitude-latitude space: each corner of the box is one of the four combinations of longitude and latitude. Such a box will generally exceed the limits of the feature. This file contains a row for each feature. Given in this row are four groups of coordinates, one for each corner of the box. The corners are expressed in three types of coordinates: (1) longitude and latitude, (2) image pixel coordinates defined by the data object IMAGE_MAP_PROJECTION in the IMPxxxxx.LBL file, and (3) the tile/pixel coordinates that correspond to these image coordinates in the tiling scheme used to store the data." /* Data object definitions */ OBJECT = TABLE INTERCHANGE_FORMAT = ASCII ROWS = 821 COLUMNS = 36 ROW_BYTES = 320 ^STRUCTURE = "GVGEO.FMT" END_OBJECT = TABLE END A.7 GVHDR.FMT Example File DESCRIPTION = "This file describes the format of the TABLE in the GVHDR.TAB file. See the GVHDR.LBL file for the full PDS label. The division of the GVDR image into tiles is described in the GVTIDX.LBL file." OBJECT = COLUMN NAME = HARDWARE_VERSION_ID_1 DATA_TYPE = ASCII_INTEGER START_BYTE = 1 BYTES = 2 DESCRIPTION = "One of three integer code numbers that identify the hardware platform and operating system used to create the data product. This code number is the most significant of the three." END_OBJECT = COLUMN OBJECT = COLUMN NAME = HARDWARE_VERSION_ID_2 DATA_TYPE = ASCII_INTEGER START_BYTE = 4 BYTES = 2 DESCRIPTION = "One of three integer code numbers that identify the hardware platform and operating system used to create the data product." END_OBJECT = COLUMN OBJECT = COLUMN NAME = HARDWARE_VERSION_ID_3 DATA_TYPE = ASCII_INTEGER START_BYTE = 7 BYTES = 2 DESCRIPTION = "One of three integer code numbers that identify the hardware platform and operating system used to create the data product. This code number is the least significant of the three." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SOFTWARE_VERSION_ID_1 DATA_TYPE = ASCII_INTEGER START_BYTE = 10 BYTES = 2 DESCRIPTION = "The major version level of the software used to create the data product." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SOFTWARE_VERSION_ID_2 DATA_TYPE = ASCII_INTEGER START_BYTE = 13 BYTES = 2 DESCRIPTION = "The minor version level of the software used to create the data product." END_OBJECT = COLUMN OBJECT = COLUMN NAME = FLOAT_FORMAT DATA_TYPE = ASCII_INTEGER START_BYTE = 16 BYTES = 2 VALID_MINIMUM = 0 VALID_MAXIMUM = 0 DESCRIPTION = "An integer code number specifying the floating point format used in the data product. It is always 0 indicating IEEE-954 floating point formats." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BYTE_FORMAT DATA_TYPE = ASCII_INTEGER START_BYTE = 19 BYTES = 2 VALID_MINIMUM = 0 VALID_MAXIMUM = 0 DESCRIPTION = "An integer code number specifying the byte order used in all multi-byte objects in the data product. It is always 0 indicating big-endian byte order (most significant byte first)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = XIF_SAMPLES_MAXIMUM DATA_TYPE = ASCII_INTEGER START_BYTE = 22 BYTES = 3 DESCRIPTION = "The maximum number of XIF samples in any single pixel. This is the largest value of the column XIF_SAMPLES in the GVDR_PIXEL_INDEX_FILE table." END_OBJECT = COLUMN OBJECT = COLUMN NAME = RDF_SAMPLES_MAXIMUM DATA_TYPE = ASCII_INTEGER START_BYTE = 26 BYTES = 3 DESCRIPTION = "The maximum number of EDF samples in any single pixel. This is the largest value of the column EDF_SAMPLES in the GVDR_PIXEL_INDEX_FILE table." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ADF_SAMPLES_MAXIMUM DATA_TYPE = ASCII_INTEGER START_BYTE = 30 BYTES = 3 DESCRIPTION = "The maximum number of ADF samples in any single pixel. This is the largest value of the column ADF_SAMPLES in the GVDR_PIXEL_INDEX_FILE table." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ANF_SAMPLES_MAXIMUM DATA_TYPE = ASCII_INTEGER START_BYTE = 34 BYTES = 3 DESCRIPTION = "The maximum number of ANF samples in any single pixel. This is the largest value of the column ANF_SAMPLES in the GVDR_PIXEL_INDEX_FILE table." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SCATTERING_ANGLE_MAXIMUM DATA_TYPE = ASCII_INTEGER START_BYTE = 38 BYTES = 3 DESCRIPTION = "The maximum value of SCATTERING_ANGLE_COUNT in any row of the GVANF file. Since all rows in a table are the same size, any row with a value less than this maximum has had its scattering law estimate padded with zeroes." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SCATTERING_FIT_MAXIMUM DATA_TYPE = ASCII_INTEGER START_BYTE = 42 BYTES = 3 DESCRIPTION = "The maximum value of SCATTERING_FIT_COUNT in any row of the GVANF file. Since all rows in a table are the same size, any row with a value less than this maximum has had its scattering law fits padded with zeroes. Normally, every row will have the full number of fits." END_OBJECT = COLUMN OBJECT = COLUMN NAME = XIF_TILE_SAMPLES_MAXIMUM DATA_TYPE = ASCII_INTEGER START_BYTE = 46 BYTES = 5 DESCRIPTION = "The maximum value of XIF_TILE_SAMPLES in any row of the GVTIDX file. This is the number of XIF samples in the tile that contains the most such samples." END_OBJECT = COLUMN OBJECT = COLUMN NAME = RDF_TILE_SAMPLES_MAXIMUM DATA_TYPE = ASCII_INTEGER START_BYTE = 52 BYTES = 5 DESCRIPTION = "The maximum value of RDF_TILE_SAMPLES in any row of the GVTIDX file. This is the number of RDF samples in the tile that contains the most such samples." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ADF_TILE_SAMPLES_MAXIMUM DATA_TYPE = ASCII_INTEGER START_BYTE = 58 BYTES = 5 DESCRIPTION = "The maximum value of ADF_TILE_SAMPLES in any row of the GVTIDX file. This is the number of ADF samples in the tile that contains the most such samples." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ANF_TILE_SAMPLES_MAXIMUM DATA_TYPE = ASCII_INTEGER START_BYTE = 64 BYTES = 5 DESCRIPTION = "The maximum value of ANF_TILE_SAMPLES in any row of the GVTIDX file. This is the number of ANF samples in the tile that contains the most such samples." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ANF_RECORD_BYTES DATA_TYPE = ASCII_INTEGER START_BYTE = 70 BYTES = 5 DESCRIPTION = "The value of RECORD_BYTES in the GVANF file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = XIF_COHORT_INCIDENCE_COUNT DATA_TYPE = ASCII_INTEGER START_BYTE = 76 BYTES = 3 DESCRIPTION = "The full range of SAR incidence angles [0,90] is divided into N equal intervals of 90/N degrees. SAR observations are grouped into 'cohorts' based on which interval their actual incidence angle occupies. The observations in a cohort are averaged together to form a single row in the GVXIF file. (Note that the observations in a cohort also share a single azimuth angle interval; thus, observations with the same incidence angle might be split into two cohorts if their azimuth angles were different.) This column gives the number of cohorts N and, indirectly, the size of the intervals used for binning and averaging of SAR data within the GVXIF file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = XIF_COHORT_AZIMUTH_COUNT DATA_TYPE = ASCII_INTEGER START_BYTE = 80 BYTES = 3 DESCRIPTION = "The full range of SAR azimuth angles [0,360] is divided into N equal intervals of 360/N degrees. SAR observations are grouped into 'cohorts' based on which interval their actual azimuth angle occupies. The observations in a cohort are averaged together to form a single row in the GVXIF file. (Note that the observations in a cohort also share a single incidence angle interval; thus, observations with the same azimuth angle might be split into two cohorts if their incidence angles were different.) This column gives the number of cohorts N and, indirectly, the size of the intervals used for binning and averaging of SAR data within the GVXIF file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = RDF_COHORT_INCIDENCE_COUNT DATA_TYPE = ASCII_INTEGER START_BYTE = 84 BYTES = 3 DESCRIPTION = "The full range of radiometry incidence angles [0,90] is divided into N equal intervals of 90/N degrees. Radiometry observations are grouped into 'cohorts' based on which interval their actual incidence angle occupies. The observations in a cohort are averaged together to form a single row in the GVRDF file. (Note that the observations in a cohort also share a single azimuth angle interval; thus, observations with the same incidence angle might be split into two cohorts if their azimuth angles were different.) This column gives the number of cohorts N and, indirectly, the size of the intervals used for binning and averaging of radiometry data within the GVRDF file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = RDF_COHORT_AZIMUTH_COUNT DATA_TYPE = ASCII_INTEGER START_BYTE = 88 BYTES = 3 DESCRIPTION = "The full range of radiometry azimuth angles [0,360] is divided into N equal intervals of 360/N degrees. Radiometry observations are grouped into 'cohorts' based on which interval their actual azimuth angle occupies. The observations in a cohort are averaged together to form a single row in the GVRDF file. (Note that the observations in a cohort also share a single incidence angle interval; thus, observations with the same azimuth angle might be split into two cohorts if their incidence angles were different.) This column gives the number of cohorts N and, indirectly, the size of the intervals used for binning and averaging of radiometry data within the GVRDF file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ANF_COHORT_AZIMUTH_COUNT DATA_TYPE = ASCII_INTEGER START_BYTE = 92 BYTES = 3 DESCRIPTION = "The full range of altimetry azimuth angles [0,360] is divided into N equal intervals of 360/N degrees. Altimetry observations are grouped into 'cohorts' based on which interval their actual azimuth angle occupies. The observations in a cohort are averaged together to form a single row in the GVANF file. This column gives the number of cohorts N and, indirectly, the size of the intervals used for binning and averaging of altimetry data within the GVANF file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = HORIZONTAL_TILE_COUNT DATA_TYPE = ASCII_INTEGER START_BYTE = 96 BYTES = 3 DESCRIPTION = "The number of tiles in the horizontal direction into which the GVDR image is divided." END_OBJECT = COLUMN OBJECT = COLUMN NAME = VERTICAL_TILE_COUNT DATA_TYPE = ASCII_INTEGER START_BYTE = 100 BYTES = 3 DESCRIPTION = "The number of tiles in the vertical direction into which the GVDR image is divided." END_OBJECT = COLUMN OBJECT = COLUMN NAME = HORIZONTAL_TILE_SIZE DATA_TYPE = ASCII_INTEGER START_BYTE = 104 BYTES = 4 DESCRIPTION = "The number of pixels in the horizontal direction in each tile." END_OBJECT = COLUMN OBJECT = COLUMN NAME = VERTICAL_TILE_SIZE DATA_TYPE = ASCII_INTEGER START_BYTE = 109 BYTES = 4 DESCRIPTION = "The number of pixels in the vertical direction in each tile." END_OBJECT = COLUMN OBJECT = COLUMN NAME = MAP_PROJECTION_ID_1 DATA_TYPE = ASCII_INTEGER START_BYTE = 114 BYTES = 2 VALID_MINIMUM = 8 VALID_MAXIMUM = 16 DESCRIPTION = "An integer code number given to each map projection. Possible values are: 8 Mercator 9 Polar Stereographic 16 Sinusoidal " END_OBJECT = COLUMN OBJECT = COLUMN NAME = MAP_PROJECTION_ID_2 DATA_TYPE = ASCII_INTEGER START_BYTE = 117 BYTES = 2 VALID_MINIMUM = 0 VALID_MAXIMUM = 3 DESCRIPTION = "An integer code number given to the region of the planet covered by the map projection. Possible values are: 0 Global (used with Sinusoidal) 1 Equatorial (used with Mercator) 2 North (used with North Polar Stereographic) 3 South (used with South Polar Stereographic) " END_OBJECT = COLUMN OBJECT = COLUMN NAME = LEFTMOST_MAP_COORD DATA_TYPE = ASCII_INTEGER START_BYTE = 120 BYTES = 5 DESCRIPTION = "The minimum x-coordinate of any pixel in this data product. The bounding box that encloses all pixels has its left edge at this value. This value is also the left side of all the leftmost tiles. The relationship between pixel coordinates and geographic location is given by the IMAGE_MAP_PROJECTION object in the IMPxxxxx.LBL file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = RIGHTMOST_MAP_COORD DATA_TYPE = ASCII_INTEGER START_BYTE = 126 BYTES = 5 DESCRIPTION = "The maximum x-coordinate of any pixel in this data product. The bounding box that encloses all pixels has its right edge at this value. Since all tiles are the same width and start at the leftmost edge of the GVDR image, this value may be less than the right side of the rightmost tiles. The relationship between pixel coordinates and geographic location is given by the IMAGE_MAP_PROJECTION object in the IMPxxxxx.LBL file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOMMOST_MAP_COORD DATA_TYPE = ASCII_INTEGER START_BYTE = 132 BYTES = 5 DESCRIPTION = "The minimum y-coordinate of any pixel in this data product. The bounding box that encloses all pixels has its bottom edge at this value. Since all tiles are the same height and start at the topmost edge of the GVDR image, this value may be less than the bottom side of the bottommost tiles. The relationship between pixel coordinates and geographic location is given by the IMAGE_MAP_PROJECTION object in the IMPxxxxx.LBL file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOPMOST_MAP_COORD DATA_TYPE = ASCII_INTEGER START_BYTE = 138 BYTES = 5 DESCRIPTION = "The maximum y-coordinate of any pixel in this data product. The bounding box that encloses all pixels has its top edge at this value. This value is also the top side of all the topmost tiles. The relationship between pixel coordinates and geographic location is given by the IMAGE_MAP_PROJECTION object in the IMPxxxxx.LBL file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = PROJECTION_LINES DATA_TYPE = ASCII_INTEGER START_BYTE = 144 BYTES = 5 DESCRIPTION = "The number of lines in the GVDR image, equal to TOPMOST_MAP_COORD - BOTTOMMOST_MAP_COORD + 1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = PROJECTION_SAMPLES DATA_TYPE = ASCII_INTEGER START_BYTE = 150 BYTES = 5 DESCRIPTION = "The number of samples in the GVDR image, equal to RIGHTMOST_MAP_COORD - LEFTMOST_MAP_COORD + 1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = A_AXIS_RADIUS DATA_TYPE = ASCII_REAL START_BYTE = 156 BYTES = 12 DESCRIPTION = "The value of A_AXIS_RADIUS in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = B_AXIS_RADIUS DATA_TYPE = ASCII_REAL START_BYTE = 169 BYTES = 12 DESCRIPTION = "The value of B_AXIS_RADIUS in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = C_AXIS_RADIUS DATA_TYPE = ASCII_REAL START_BYTE = 182 BYTES = 12 DESCRIPTION = "The value of C_AXIS_RADIUS in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = FIRST_STANDARD_PARALLEL DATA_TYPE = ASCII_REAL START_BYTE = 195 BYTES = 10 VALID_MINIMUM = 0 VALID_MAXIMUM = 360 DESCRIPTION = "The value of FIRST_STANDARD_PARALLEL in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SECOND_STANDARD_PARALLEL DATA_TYPE = ASCII_REAL START_BYTE = 206 BYTES = 10 VALID_MINIMUM = 0 VALID_MAXIMUM = 360 DESCRIPTION = "The value of SECOND_STANDARD_PARALLEL in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = CENTER_LATITUDE DATA_TYPE = ASCII_REAL START_BYTE = 217 BYTES = 10 VALID_MINIMUM = -90 VALID_MAXIMUM = 90 DESCRIPTION = "The value of CENTER_LATITUDE in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = CENTER_LONGITUDE DATA_TYPE = ASCII_REAL START_BYTE = 228 BYTES = 10 VALID_MINIMUM = -90 VALID_MAXIMUM = 90 DESCRIPTION = "The value of CENTER_LONGITUDE in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = LINE_FIRST_PIXEL DATA_TYPE = ASCII_INTEGER START_BYTE = 239 BYTES = 5 DESCRIPTION = "The value of LINE_FIRST_PIXEL in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = LINE_LAST_PIXEL DATA_TYPE = ASCII_INTEGER START_BYTE = 245 BYTES = 5 DESCRIPTION = "The value of LINE_LAST_PIXEL in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SAMPLE_FIRST_PIXEL DATA_TYPE = ASCII_INTEGER START_BYTE = 251 BYTES = 5 DESCRIPTION = "The value of SAMPLE_FIRST_PIXEL in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SAMPLE_LAST_PIXEL DATA_TYPE = ASCII_INTEGER START_BYTE = 257 BYTES = 5 DESCRIPTION = "The value of SAMPLE_LAST_PIXEL in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = MAP_PROJECTION_ROTATION DATA_TYPE = ASCII_REAL START_BYTE = 263 BYTES = 10 DESCRIPTION = "The value of MAP_PROJECTION_ROTATION in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = MAP_RESOLUTION DATA_TYPE = ASCII_REAL START_BYTE = 274 BYTES = 10 DESCRIPTION = "The value of MAP_RESOLUTION in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = MAP_SCALE DATA_TYPE = ASCII_REAL START_BYTE = 285 BYTES = 10 DESCRIPTION = "The value of MAP_SCALE in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = MINIMUM_LATITUDE DATA_TYPE = ASCII_REAL START_BYTE = 296 BYTES = 10 VALID_MINIMUM = -90 VALID_MAXIMUM = 90 DESCRIPTION = "The value of MINIMUM_LATITUDE in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = MAXIMUM_LATITUDE DATA_TYPE = ASCII_REAL START_BYTE = 307 BYTES = 10 VALID_MINIMUM = -90 VALID_MAXIMUM = 90 DESCRIPTION = "The value of MAXIMUM_LATITUDE in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = WESTERNMOST_LONGITUDE DATA_TYPE = ASCII_REAL START_BYTE = 318 BYTES = 10 VALID_MINIMUM = -180 VALID_MAXIMUM = 360 DESCRIPTION = "The value of WESTERNMOST_LONGITUDE in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = EASTERNMOST_LONGITUDE DATA_TYPE = ASCII_REAL START_BYTE = 329 BYTES = 10 VALID_MINIMUM = -180 VALID_MAXIMUM = 360 DESCRIPTION = "The value of EASTERNMOST_LONGITUDE in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = LINE_PROJECTION_OFFSET DATA_TYPE = ASCII_REAL START_BYTE = 340 BYTES = 10 DESCRIPTION = "The value of LINE_PROJECTION_OFFSET in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SAMPLE_PROJECTION_OFFSET DATA_TYPE = ASCII_REAL START_BYTE = 351 BYTES = 10 DESCRIPTION = "The value of SAMPLE_PROJECTION_OFFSET in the IMAGE_MAP_PROJECTION object that defines the map projection." END_OBJECT = COLUMN A.8 GVHDR.LBL Example File PDS_VERSION_ID = PDS3 /* File characteristics */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 362 FILE_RECORDS = 1 /* Data object pointer */ ^TABLE = "GVHDR.TAB" /* Identification data elements */ DATA_SET_ID = "MGN-V-RDRS-5-GVDR-V1.0" DATA_SET_NAME = "MAGELLAN VENUS RADAR SYSTEM GLOBAL DATA RECORD V1.0" PRODUCT_ID = "GVHDR-MERC.100" MISSION_NAME = "MAGELLAN" SPACECRAFT_NAME = "MAGELLAN" INSTRUMENT_NAME = "RADAR SYSTEM" TARGET_NAME = "VENUS" ORBIT_START_NUMBER = 376 ORBIT_STOP_NUMBER = 5747 START_TIME = "N/A" STOP_TIME = "N/A" SPACECRAFT_CLOCK_START_COUNT = "N/A" SPACECRAFT_CLOCK_STOP_COUNT = "N/A" PRODUCT_CREATION_TIME = 1994-05-10T22:21:45.000 PRODUCT_RELEASE_DATE = 1994-05-13 PRODUCT_SEQUENCE_NUMBER = 00000 PRODUCT_VERSION_TYPE = "PRELIMINARY" SOURCE_DATA_SET_ID = {"MGN-V-RDRS-5-SCVDR-V1.0", "MGN-V-RDRS-CDR-ALT/RAD-V1.0"} SOURCE_PRODUCT_ID = {"SCVDR.00376-00399.1", "SCVDR.00400-00499.1","SCVDR.01100-01199.1","SCVDR.01200-01299.1", "SCVDR.01300-01399.1","SCVDR.01400-01499.1","SCVDR.01500-01599.1", "SCVDR.01600-01699.1","SCVDR.01700-01799.1","SCVDR.01800-01899.1", "SCVDR.01900-01999.1","SCVDR.02000-02099.1","SCVDR.02100-02199.1", "SCVDR.00500-00599.2","SCVDR.00600-00676.2","SCVDR.00787-00799.2", "SCVDR.00800-00899.2","SCVDR.00900-00999.2","SCVDR.01000-01099.2", "SCVDR.02200-02299.2","SCVDR.02400-02499.2","SCVDR.02500-02599.2", "SCVDR.02300-02399.1","ARCDRCD.001;2","ARCDRCD.002;1","ARCDRCD.003;1", "ARCDRCD.004;1","ARCDRCD.005;1","ARCDRCD.006;1","ARCDRCD.007;1", "ARCDRCD.008;1","ARCDRCD.009;1","ARCDRCD.010;1","ARCDRCD.011;1", "ARCDRCD.012;1","ARCDRCD.013;1","ARCDRCD.014;1","ARCDRCD.015;1", "ARCDRCD.016;1","ARCDRCD.017;1","ARCDRCD.018;1","ARCDRCD.019;1"} SOFTWARE_FLAG = "Y" PRODUCER_FULL_NAME = "Michael J. Maurer" PRODUCER_INSTITUTION_NAME = "Stanford Center for Radar Astronomy" PRODUCER_ID = "SCRA" DESCRIPTION = "The GVHDR file contains a table with a single row of entries. Most of the information in this table is available from other PDS label files and is therefore redundant. It is collected here for the convenience of the GVDR processing software provided in the SOFTWARE directory of this volume." /* Data object definitions */ OBJECT = TABLE INTERCHANGE_FORMAT = ASCII ROWS = 1 COLUMNS = 55 ROW_BYTES = 362 ^STRUCTURE = "GVHDR.FMT" END_OBJECT = TABLE END A.9 GVNFF.FMT Example File /* This file describes the data elements in the */ /* SCATTERING_LAW_FITS_CONTAINER in the GVANF file. */ /* (See the GVANF.LBL and GVANF.FMT label files for details). */ OBJECT = COLUMN NAME = SCATTERING_LAW_ID DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 1 BYTES = 1 VALID_MINIMUM = 0 VALID_MAXIMUM = 4 DESCRIPTION = "Identification number that specifies the analytic scattering law used to fit the observed scattering law. The possible ID numbers and scattering models are 0 Hagfors 1 Exponential 2 Gaussian 3 Rayleigh 4 Muhleman The scattering model determines the interpretation of the remaining fields." END_OBJECT = COLUMN OBJECT = COLUMN NAME = FIT_FLAG_GROUP DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 2 BYTES = 1 DESCRIPTION = "A collection of bit flags describing the results of fitting the observed scattering law to the analytic model. If the corresponding bit is 1, the flag is set. The bit values are 0x01 Fit failed: FIT_PARAMETER_1 too large 0x02 Fit failed: FIT_PARAMETER_1 too small 0x80 Fit failed: unknown error The other bit positions are unused." END_OBJECT = COLUMN OBJECT = COLUMN NAME = FIT_PARAMETER_1 DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 3 BYTES = 1 UNIT = "N/A" /* see DESCRIPTION */ DESCRIPTION = "The first parameter solved for in the fit to the observed scattering law. The interpretation of this parameter varies with the scattering model, but for most of them is a measure of the rms roughness of the surface. See the GVDR SIS for a complete description of this field." END_OBJECT = COLUMN OBJECT = COLUMN NAME = FIT_PARAMETER_1_VARIANCE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 4 BYTES = 1 UNIT = "N/A" /* see DESCRIPTION */ DESCRIPTION = "The formal variance of the first fitted parameter, computed using linear propagation of errors through the least squares solution. Since the variance on the observed scattering law estimate is sometimes questionable, this field should be used with caution." END_OBJECT = COLUMN OBJECT = COLUMN NAME = FIT_PARAMETER_2 DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 5 BYTES = 1 OFFSET = -3 SCALING_FACTOR = 0.012 UNIT = "N/A" /* see DESCRIPTION */ DESCRIPTION = "The second parameter solved for in the fit to the observed scattering law. The interpretation of this parameter varies with the scattering model, but for most of them is a measure of the bulk reflectivity of the surface. See the GVDR SIS for a complete description of this field." END_OBJECT = COLUMN OBJECT = COLUMN NAME = FIT_PARAMETER_2_VARIANCE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 6 BYTES = 1 OFFSET = -9 SCALING_FACTOR = 0.036 UNIT = "N/A" /* see DESCRIPTION */ DESCRIPTION = "The formal variance of the second fitted parameter, computed using linear propagation of errors through the least squares solution. Since the variance on the observed scattering law estimate is sometimes questionable, this field should be used with caution." END_OBJECT = COLUMN OBJECT = COLUMN NAME = FIT_RMS_SLOPE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 7 BYTES = 1 OFFSET = 0 SCALING_FACTOR = 0.08 UNIT = RADIAN VALID_MINIMUM = 0 VALID_MAXIMUM = 20 DESCRIPTION = "The rms surface slope associated with the fit parameters above. This field is computed from analytic expressions for the rms slope implied by a given model, and is quite dependent on that model." END_OBJECT = COLUMN OBJECT = COLUMN NAME = FIT_RMS_SLOPE_VARIANCE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 8 BYTES = 1 OFFSET = -6 SCALING_FACTOR = 0.028 UNIT = "N/A" /* see DESCRIPTION */ DESCRIPTION = "The formal variance of the rms slope given above, computed using linear propagation of errors through the least squares solution and analytic expression for rms slope. Since the variance on the observed scattering law estimate is sometimes questionable, this field should be used with caution. The units of this field are log10(radian-squared). To obtain the actual variance, raise 10 to the value reported here. The result will be in radians-squared." END_OBJECT = COLUMN OBJECT = COLUMN NAME = FIT_RESIDUAL DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 9 BYTES = 1 OFFSET = 0 SCALING_FACTOR = 2 VALID_MINIMUM = 0 VALID_MAXIMUM = 500 DESCRIPTION = "The formal residual of the model's fit to the observed scattering law. It is the sum of squares of the difference between the observed scattering law and the model's prediction, summed over the incidence angles reported in SCATTERING_ANGLE_COUNT. When interpreting the residual, the number of degrees of freedom is two less than the number of angles, because of the two fitted parameters. Since the variance on the observed scattering law estimate is sometimes questionable, this field should be used with caution." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SPARE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 10 BYTES = 1 DESCRIPTION = "Unused space to pad the row to an even number of bytes." END_OBJECT = COLUMN A.10 GVORB.FMT Example File DESCRIPTION = "This file describes the format of the TABLE in the GVORB.TAB file. See the GVORB.LBL file for the full PDS label." OBJECT = COLUMN NAME = SOURCE_FILE_NAME DATA_TYPE = CHARACTER START_BYTE = 2 BYTES = 11 DESCRIPTION = "The file name of the data file used as a source for this GVDR. This data file was part of an SCVDR or ARCDRCD data product." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOTAL_FOOTPRINT_COUNT DATA_TYPE = ASCII_INTEGER START_BYTE = 15 BYTES = 6 DESCRIPTION = "The total number of footprints from the data file in SOURCE_FILE_NAME considered for inclusion in the GVDR. This is the number of footprints that entirely or partially overlapped the extents of the map projection in use." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ACCEPTED_FOOTPRINT_COUNT DATA_TYPE = ASCII_INTEGER START_BYTE = 22 BYTES = 6 DESCRIPTION = "The number of footprints actually used in the GVDR. Footprints may be rejected on the basis of header flags recommending against their use or other suspected problems." END_OBJECT = COLUMN OBJECT = COLUMN NAME = REJECTED_FOOTPRINT_COUNT DATA_TYPE = ASCII_INTEGER START_BYTE = 29 BYTES = 6 DESCRIPTION = "The number of footprints rejected and not used in the GVDR. Footprints may be rejected on the basis of header flags recommending against their use or other suspected problems." END_OBJECT = COLUMN A.11 GVORB.LBL Example File PDS_VERSION_ID = PDS3 /* File characteristics */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 36 FILE_RECORDS = 12041 /* Data object pointer */ ^TABLE = "GVORB.TAB" /* Identification data elements */ DATA_SET_ID = "MGN-V-RDRS-5-GVDR-V1.0" DATA_SET_NAME = "MAGELLAN VENUS RADAR SYSTEM GLOBAL DATA RECORD V1.0" PRODUCT_ID = "GVORB-MERC.100" MISSION_NAME = "MAGELLAN" SPACECRAFT_NAME = "MAGELLAN" INSTRUMENT_NAME = "RADAR SYSTEM" TARGET_NAME = "VENUS" ORBIT_START_NUMBER = 376 ORBIT_STOP_NUMBER = 5747 START_TIME = "N/A" STOP_TIME = "N/A" SPACECRAFT_CLOCK_START_COUNT = "N/A" SPACECRAFT_CLOCK_STOP_COUNT = "N/A" PRODUCT_CREATION_TIME = 1994-05-10T22:21:53.000 PRODUCT_RELEASE_DATE = 1994-05-13 PRODUCT_SEQUENCE_NUMBER = 00000 PRODUCT_VERSION_TYPE = "PRELIMINARY" SOURCE_DATA_SET_ID = {"MGN-V-RDRS-5-SCVDR-V1.0", "MGN-V-RDRS-CDR-ALT/RAD-V1.0"} SOURCE_PRODUCT_ID = {"SCVDR.00376-00399.1", "SCVDR.00400-00499.1","SCVDR.01100-01199.1","SCVDR.01200-01299.1", "SCVDR.01300-01399.1","SCVDR.01400-01499.1","SCVDR.01500-01599.1", "SCVDR.01600-01699.1","SCVDR.01700-01799.1","SCVDR.01800-01899.1", "SCVDR.01900-01999.1","SCVDR.02000-02099.1","SCVDR.02100-02199.1", "SCVDR.00500-00599.2","SCVDR.00600-00676.2","SCVDR.00787-00799.2", "SCVDR.00800-00899.2","SCVDR.00900-00999.2","SCVDR.01000-01099.2", "SCVDR.02200-02299.2","SCVDR.02400-02499.2","SCVDR.02500-02599.2", "SCVDR.02300-02399.1","ARCDRCD.001;2","ARCDRCD.002;1","ARCDRCD.003;1", "ARCDRCD.004;1","ARCDRCD.005;1","ARCDRCD.006;1","ARCDRCD.007;1", "ARCDRCD.008;1","ARCDRCD.009;1","ARCDRCD.010;1","ARCDRCD.011;1", "ARCDRCD.012;1","ARCDRCD.013;1","ARCDRCD.014;1","ARCDRCD.015;1", "ARCDRCD.016;1","ARCDRCD.017;1","ARCDRCD.018;1","ARCDRCD.019;1"} SOFTWARE_FLAG = "Y" PRODUCER_FULL_NAME = "Michael J. Maurer" PRODUCER_INSTITUTION_NAME = "Stanford Center for Radar Astronomy" PRODUCER_ID = "SCRA" DESCRIPTION = "This file gives the provenance of the data used to create the GVDR. Each row contains a reference to a data file from either the SCVDR or ARCDR data products. (All such products used are enumerated in SOURCE_PRODUCT_ID above.) The number of candidate observations and the number actually used is also provided." /* Data object definitions */ OBJECT = TABLE INTERCHANGE_FORMAT = ASCII ROWS = 12041 COLUMNS = 4 ROW_BYTES = 36 ^STRUCTURE = "GVORB.FMT" END_OBJECT = TABLE END A.12 GVPIDX.FMT Example File DESCRIPTION = "This file describes the format of the TABLE in the GVPIDX.TAB file. See the GVPIDX.LBL file for the full PDS label." OBJECT = COLUMN NAME = XIF_START DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 1 BYTES = 2 VALID_MINIMUM = 0 VALID_MAXIMUM = 1970 DESCRIPTION = "The row in the GVDR_XIF_TABLE containing the first XIF sample for this pixel, with numbering starting at 0 at the first pixel in this tile. To find the absolute row number, add the XIF_START to the value of XIF_TILE_START from the appropriate row in the GVDR_TILE_INDEX_TABLE. If there are no XIF samples (that is, if the value of XIF_SAMPLES is zero), the value of this field is set to zero." END_OBJECT = COLUMN OBJECT = COLUMN NAME = RDF_START DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 3 BYTES = 2 VALID_MINIMUM = 0 VALID_MAXIMUM = 7661 DESCRIPTION = "The row in the GVDR_RDF_TABLE containing the first RDF sample for this pixel, with numbering starting at 0 at the first pixel in this tile. To find the absolute row number, add the RDF_START to the value of RDF_TILE_START from the appropriate row in the GVDR_TILE_INDEX_TABLE. If there are no RDF samples (that is, if the value of RDF_SAMPLES is zero), the value of this field is set to zero." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ADF_START DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 5 BYTES = 2 VALID_MINIMUM = 0 VALID_MAXIMUM = 1023 DESCRIPTION = "The row in the GVDR_ADF_TABLE containing the first ADF sample for this pixel, with numbering starting at 0 at the first pixel in this tile. To find the absolute row number, add the ADF_START to the value of ADF_TILE_START from the appropriate row in the GVDR_TILE_INDEX_TABLE. If there are no ADF samples (that is, if the value of ADF_SAMPLES is zero), the value of this field is set to zero." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ANF_START DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 7 BYTES = 2 VALID_MINIMUM = 0 VALID_MAXIMUM = 1023 DESCRIPTION = "The row in the GVDR_ANF_TABLE containing the first ANF sample for this pixel, with numbering starting at 0 at the first pixel in this tile. To find the absolute row number, add the ANF_START to the value of ANF_TILE_START from the appropriate row in the GVDR_TILE_INDEX_TABLE. If there are no ANF samples (that is, if the value of ADF_SAMPLES is zero), the value of this field is set to zero." END_OBJECT = COLUMN OBJECT = COLUMN NAME = XIF_SAMPLES DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 9 BYTES = 1 VALID_MINIMUM = 0 VALID_MAXIMUM = 4 DESCRIPTION = "The number of XIF samples for this pixel. These samples are found consecutively in the GVDR_XIF_TABLE starting at the row indicated by XIF_START." END_OBJECT = COLUMN OBJECT = COLUMN NAME = RDF_SAMPLES DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 10 BYTES = 1 VALID_MINIMUM = 0 VALID_MAXIMUM = 15 DESCRIPTION = "The number of RDF samples for this pixel. These samples are found consecutively in the GVDR_RDF_TABLE starting at the row indicated by RDF_START." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ADF_SAMPLES DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 11 BYTES = 1 VALID_MINIMUM = 0 VALID_MAXIMUM = 1 DESCRIPTION = "The number of ADF samples for this pixel. These samples are found consecutively in the GVDR_ADF_TABLE starting at the row indicated by ADF_START." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ANF_SAMPLES DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 12 BYTES = 1 VALID_MINIMUM = 0 VALID_MAXIMUM = 1 DESCRIPTION = "The number of ANF samples for this pixel. These samples are found consecutively in the GVDR_ANF_TABLE starting at the row indicated by ANF_START." END_OBJECT = COLUMN A.13 GVPIDX.LBL Example File PDS_VERSION_ID = PDS3 /* File characteristics */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 12 FILE_RECORDS = 2161664 /* Data object pointer */ ^TABLE = "GVPIDX.TAB" /* Identification data elements */ DATA_SET_ID = "MGN-V-RDRS-5-GVDR-V1.0" DATA_SET_NAME = "MAGELLAN VENUS RADAR SYSTEM GLOBAL DATA RECORD V1.0" PRODUCT_ID = "GVPIDX-MERC.100" MISSION_NAME = "MAGELLAN" SPACECRAFT_NAME = "MAGELLAN" INSTRUMENT_NAME = "RADAR SYSTEM" TARGET_NAME = "VENUS" ORBIT_START_NUMBER = 376 ORBIT_STOP_NUMBER = 5747 START_TIME = "N/A" STOP_TIME = "N/A" SPACECRAFT_CLOCK_START_COUNT = "N/A" SPACECRAFT_CLOCK_STOP_COUNT = "N/A" PRODUCT_CREATION_TIME = 1994-05-10T22:21:57.000 PRODUCT_RELEASE_DATE = 1994-05-13 PRODUCT_SEQUENCE_NUMBER = 00000 PRODUCT_VERSION_TYPE = "PRELIMINARY" SOURCE_DATA_SET_ID = {"MGN-V-RDRS-5-SCVDR-V1.0", "MGN-V-RDRS-CDR-ALT/RAD-V1.0"} SOURCE_PRODUCT_ID = {"SCVDR.00376-00399.1", "SCVDR.00400-00499.1","SCVDR.01100-01199.1","SCVDR.01200-01299.1", "SCVDR.01300-01399.1","SCVDR.01400-01499.1","SCVDR.01500-01599.1", "SCVDR.01600-01699.1","SCVDR.01700-01799.1","SCVDR.01800-01899.1", "SCVDR.01900-01999.1","SCVDR.02000-02099.1","SCVDR.02100-02199.1", "SCVDR.00500-00599.2","SCVDR.00600-00676.2","SCVDR.00787-00799.2", "SCVDR.00800-00899.2","SCVDR.00900-00999.2","SCVDR.01000-01099.2", "SCVDR.02200-02299.2","SCVDR.02400-02499.2","SCVDR.02500-02599.2", "SCVDR.02300-02399.1","ARCDRCD.001;2","ARCDRCD.002;1","ARCDRCD.003;1", "ARCDRCD.004;1","ARCDRCD.005;1","ARCDRCD.006;1","ARCDRCD.007;1", "ARCDRCD.008;1","ARCDRCD.009;1","ARCDRCD.010;1","ARCDRCD.011;1", "ARCDRCD.012;1","ARCDRCD.013;1","ARCDRCD.014;1","ARCDRCD.015;1", "ARCDRCD.016;1","ARCDRCD.017;1","ARCDRCD.018;1","ARCDRCD.019;1"} SOFTWARE_FLAG = "Y" PRODUCER_FULL_NAME = "Michael J. Maurer" PRODUCER_INSTITUTION_NAME = "Stanford Center for Radar Astronomy" PRODUCER_ID = "SCRA" DESCRIPTION = "This file is the pixel index, used in the second step in all pixel lookup operations. See the description of the GVTIDX file for a discussion of how to use this file. Each row in the GVPIDX file corresponds to a single pixel, and its elements are pointers to the rows, relative to the start of the tile, at which that pixel begins. The GVPIDX elements also give the number of rows associated with the pixel in question." /* Data object definitions */ OBJECT = TABLE INTERCHANGE_FORMAT = BINARY ROWS = 2161664 COLUMNS = 8 ROW_BYTES = 12 ^STRUCTURE = "GVPIDX.FMT" END_OBJECT = TABLE END A.14 GVRDF.FMT Example File DESCRIPTION = "This file describes the format of the TABLE in the GVRDF.TAB file. See the GVRDF.LBL file for the full PDS label." OBJECT = COLUMN NAME = SAMPLE_COUNT DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 1 BYTES = 2 DESCRIPTION = "The total number of radiometer footprints used to compute the estimates of thermal emission properties given in this row of the table. The quantities given in later columns pertain only these footprints. Any radiometry footprint that is partially or completely contained inside this pixel is included. Each footprint is derived from a single record in the ARCDRCD RDF file. The footprints used in this row share a common observational geometry, given explicitly by the columns AZIMUTH_ANGLE, INCIDENCE_ANGLE, and POLARIZATION_ANGLE, and implicitly by the pixel address. This pixel may have entries in other rows, and if so at least one of the three angles will be different from this row." END_OBJECT = COLUMN OBJECT = COLUMN NAME = AZIMUTH_ANGLE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 3 BYTES = 2 OFFSET = 0 SCALING_FACTOR = 0.00549367 UNIT = DEGREE VALID_MINIMUM = 0 VALID_MAXIMUM = 360 DESCRIPTION = "The average azimuthal angle of the radiometry observations. The azimuthal angle is defined in two ways, depending on the image map projection in use. For the Sinusoidal and Mercator map projections, it is defined as the local azimuth direction toward the spacecraft when viewed by an observer at the boresight intercept point on the planet surface, in degrees clockwise from North. For example, if the spacecraft appears to be due east of the observer, the azimuth angle is 90 degrees. Since this definition becomes useless near the poles, this field is set to zero above 85 degrees of latitude for the Sinusoidal projection. The Mercator projection does not extend to such high latitudes. For the Polar Stereographic map projection, the azimuth angle is expressed in the cartesian map coordinates rather than in geographic coordinates. This makes the azimuth angle more useful for interpretation because its meaning no longer varies with position. First, the azimuth direction is computed as above. Then, this direction is transformed to a direction in map coordinates; the transformed vector is parallel to the vector originating at the framelet and pointing in the azimuth direction. This vector is expressed in degrees clockwise from the +Y (up) direction on the map. For example, if the north polar projection has 0 degrees of longitude at the bottom, then a framelet at 90 degrees of longitude with a true azimuth of 90 degrees (spacecraft to the east) has a transformed azimuth of 0 degrees. The vector from the framelet to the spacecraft appears to point in the +Y direction on the map. The relationship between true azimuth and transformed azimuth is simple. For the north polar projection with 0 degrees longitude at the bottom, CARTESIAN_AZIMUTH = GEOGRAPHIC_AZIMUTH - LONGITUDE and for the south polar projection with 0 degrees longitude at the top, CARTESIAN_AZIMUTH = GEOGRAPHIC_AZIMUTH + LONGITUDE As discussed in the GVHDR.LBL file, the group of radiometry observations used in this row forms a 'cohort'. Within a cohort, the azimuth angle of each observation falls within a single interval of size 360/N, where N is the value of RDF_COHORT_AZIMUTH_COUNT from the GVHDR file. We can reconstruct that interval by noting that the average azimuth angle of all the observations (given in this column) falls within the same interval. Specifically, we find a value of I that satisfies I * 360.0 / N <= AZIMUTH_ANGLE < (I+1) * 360.0 / N where N = RDF_COHORT_AZIMUTH_COUNT I = integer between 0 and N-1 inclusive The azimuth angles of all observations in the cohort lie in the interval [I*360 , (I+1)*360), and their average value is given in this column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = INCIDENCE_ANGLE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 5 BYTES = 2 OFFSET = 0 SCALING_FACTOR = 0.00137342 UNIT = DEGREE VALID_MINIMUM = 0 VALID_MAXIMUM = 90 DESCRIPTION = "The average emission angle of the radiometry observations. This is the angle between the local mean surface normal and the direction of the emitted radiation on its way to the spacecraft. Normal emission is thus 0 degrees, and grazing emission is 90 degrees. This quantity is obtained directly from the ARCDRCD RDF field INCIDENCE_ANGLE (alias RR_ANGLE). As discussed in the GVHDR.LBL file, the group of radiometry observations used in this row forms a 'cohort'. Within a cohort, the incidence angle of each observation falls within a single interval of size 90/N, where N is the value of RDF_COHORT_INCIDENCE_COUNT from the GVHDR file. We can reconstruct that interval by noting that the average incidence angle of all the observations (given in this column) falls within the same interval. Specifically, we find a value of I that satisfies I * 90.0 / N <= INCIDENCE_ANGLE < (I+1) * 90.0 / N where N = RDF_COHORT_INCIDENCE_COUNT I = integer between 0 and N-1 inclusive The incidence angles of all observations in the cohort lie in the interval [I*90 , (I+1)*90), and their average value is given in this column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = POLARIZATION_ANGLE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 7 BYTES = 1 OFFSET = -90 SCALING_FACTOR = 0.72 UNIT = DEGREE VALID_MINIMUM = -90 VALID_MAXIMUM = 90 DESCRIPTION = "The average polarization angle of the received radiation. The polarization angle is defined to be +/- 90 degrees for H-H polarization (+90 is nominal for mission cycle 1) and 0 degrees for V-V polarization. Nearly all orbits maintained an almost constant H-H or V-V polarization angle; the values of 90 or 0 reported for these orbits are only nominal and are not based on actual geometric calculations. Only values that differ from 90 or 0 have been actually computed." END_OBJECT = COLUMN OBJECT = COLUMN NAME = EMISSIVITY_VARIANCE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 8 BYTES = 1 OFFSET = -5 SCALING_FACTOR = 0.016000 VALID_MINIMUM = 0.000010 VALID_MAXIMUM = 0.100000 DESCRIPTION = "The unbiased estimate of the variance of the emissivity. The emissivity is obtained from the SURFACE_EMISSIVITY field (alias RR_EMISS) in the ARCDRCD. The variance estimate gives an indication of the variation in emissivity across the pixel. The unbiased estimate is obtained from the following formula: EMISSIVITY_VARIANCE = 1/(N-1) * ( SUM(X_i^2) - 1/N * [SUM(X_i)]^2 ) where N = SAMPLE_COUNT above X_i = samples of radius RR_EMISS, i = 1,2,...,N. The value in the table is the base-10 logarithm of the actual value. To recover the actual value, apply the scaling and offsets given above to the column value, and raise 10 to this power." END_OBJECT = COLUMN OBJECT = COLUMN NAME = EMISSIVITY DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 9 BYTES = 2 OFFSET = 0 SCALING_FACTOR = 0.000015260 VALID_MINIMUM = 0 VALID_MAXIMUM = 1 DESCRIPTION = "The average emissivity estimate. The emissivity value for each footprint is obtained directly from the ARCDRCD RDF field SURFACE_EMISSIVITY (alias RR_EMISS). At the moment, the measurements are not weighted based on the footprint center's distance from the pixel center." END_OBJECT = COLUMN A.15 GVRDF.LBL Example File PDS_VERSION_ID = PDS3 /* File characteristics */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 10 FILE_RECORDS = 4277107 /* Data object pointer */ ^TABLE = "GVRDF.TAB" /* Identification data elements */ DATA_SET_ID = "MGN-V-RDRS-5-GVDR-V1.0" DATA_SET_NAME = "MAGELLAN VENUS RADAR SYSTEM GLOBAL DATA RECORD V1.0" PRODUCT_ID = "GVRDF-MERC.100" MISSION_NAME = "MAGELLAN" SPACECRAFT_NAME = "MAGELLAN" INSTRUMENT_NAME = "RADAR SYSTEM" TARGET_NAME = "VENUS" ORBIT_START_NUMBER = 376 ORBIT_STOP_NUMBER = 5747 START_TIME = "N/A" STOP_TIME = "N/A" SPACECRAFT_CLOCK_START_COUNT = "N/A" SPACECRAFT_CLOCK_STOP_COUNT = "N/A" PRODUCT_CREATION_TIME = 1994-05-10T22:21:59.000 PRODUCT_RELEASE_DATE = 1994-05-13 PRODUCT_SEQUENCE_NUMBER = 00000 PRODUCT_VERSION_TYPE = "PRELIMINARY" SOURCE_DATA_SET_ID = {"MGN-V-RDRS-CDR-ALT/RAD-V1.0"} SOURCE_PRODUCT_ID = {"ARCDRCD.001;2","ARCDRCD.002;1", "ARCDRCD.003;1","ARCDRCD.004;1","ARCDRCD.005;1","ARCDRCD.006;1", "ARCDRCD.007;1","ARCDRCD.008;1","ARCDRCD.009;1","ARCDRCD.010;1", "ARCDRCD.011;1","ARCDRCD.012;1","ARCDRCD.013;1","ARCDRCD.014;1", "ARCDRCD.015;1","ARCDRCD.016;1","ARCDRCD.017;1","ARCDRCD.018;1", "ARCDRCD.019;1"} SOFTWARE_FLAG = "Y" PRODUCER_FULL_NAME = "Michael J. Maurer" PRODUCER_INSTITUTION_NAME = "Stanford Center for Radar Astronomy" PRODUCER_ID = "SCRA" DESCRIPTION = "The GVRDF file contains measures of the surface's thermal radiative efficiency derived from the side-looking microwave radiometer. (The RDF acronym stands for 'Radiometry Data File', one of the data files in the ARCDR data product. Within the software documentation, the acronym EDF, or 'Emissivity Data File', from the SCVDR data product, may also be used because of its similarity to the RDF.) This file is a table; each row in the table summarizes RDF results in a particular radiometry viewing geometry. The location and number of rows associated with each pixel are given by the corresponding values of RDF_START and RDF_SAMPLES in GVPIDX.TAB. See the descriptions in the GVTIDX.LBL and GVPIDX.LBL files for the overall organization of the GVDR. These files describe the division of the planet into pixels and organization of pixels into rectangular tiles." /* Data object definitions */ OBJECT = TABLE INTERCHANGE_FORMAT = BINARY ROWS = 4277107 COLUMNS = 6 ROW_BYTES = 10 ^STRUCTURE = "GVRDF.FMT" END_OBJECT = TABLE END A.16 GVTGEOM.FMT Example File DESCRIPTION = "This file describes the format of the TABLE in the GVTGEOM.TAB file. See the GVTGEOM.LBL file for the full PDS label." OBJECT = COLUMN NAME = TILE_COORD_X DATA_TYPE = ASCII_INTEGER START_BYTE = 1 BYTES = 5 DESCRIPTION = "The x-coordinate of the tile, with the leftmost tile at zero and coordinates increasing to the right. This is analogous to the SAMPLE value in PDS format IMAGEs. (Note that these 'tile coordinates' are unrelated to the pixel coordinates; they simply address the tile relative to the upper left tile [0,0].) The relationship between pixel coordinates and geographic location is given by the IMAGE_MAP_PROJECTION object in the IMPxxxxx.LBL file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TILE_COORD_Y DATA_TYPE = ASCII_INTEGER START_BYTE = 7 BYTES = 4 DESCRIPTION = "The y-coordinate of the tile, with the topmost tile at zero and coordinates increasing downward. This is analogous to the LINE value in PDS format IMAGEs. (Note that these 'tile coordinates' are unrelated to the pixel coordinates; they simply address the tile relative to the upper left tile [0,0].) The relationship between pixel coordinates and geographic location is given by the IMAGE_MAP_PROJECTION object in the IMPxxxxx.LBL file." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_LEFT_LONGITUDE DATA_TYPE = ASCII_REAL UNIT = DEGREE START_BYTE = 12 BYTES = 8 DESCRIPTION = "The longitude at the center of the pixel in the upper left corner of the tile." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_LEFT_LATITUDE DATA_TYPE = ASCII_REAL UNIT = DEGREE START_BYTE = 21 BYTES = 8 DESCRIPTION = "The latitude at the center of the pixel in the upper left corner of the tile." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_RIGHT_LONGITUDE DATA_TYPE = ASCII_REAL UNIT = DEGREE START_BYTE = 30 BYTES = 8 DESCRIPTION = "The longitude at the center of the pixel in the upper right corner of the tile." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TOP_RIGHT_LATITUDE DATA_TYPE = ASCII_REAL UNIT = DEGREE START_BYTE = 39 BYTES = 8 DESCRIPTION = "The latitude at the center of the pixel in the upper right corner of the tile." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_LEFT_LONGITUDE DATA_TYPE = ASCII_REAL UNIT = DEGREE START_BYTE = 48 BYTES = 8 DESCRIPTION = "The longitude at the center of the pixel in the lower left corner of the tile." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_LEFT_LATITUDE DATA_TYPE = ASCII_REAL UNIT = DEGREE START_BYTE = 57 BYTES = 8 DESCRIPTION = "The latitude at the center of the pixel in the lower left corner of the tile." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_RIGHT_LONGITUDE DATA_TYPE = ASCII_REAL UNIT = DEGREE START_BYTE = 66 BYTES = 8 DESCRIPTION = "The longitude at the center of the pixel in the lower right corner of the tile." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BOTTOM_RIGHT_LATITUDE DATA_TYPE = ASCII_REAL UNIT = DEGREE START_BYTE = 75 BYTES = 8 DESCRIPTION = "The latitude at the center of the pixel in the lower right corner of the tile." END_OBJECT = COLUMN A.17 GVTGEOM.LBL Example File PDS_VERSION_ID = PDS3 /* File characteristics */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 84 FILE_RECORDS = 2112 /* Data object pointer */ ^TABLE = "GVTGEOM.TAB" /* Identification data elements */ DATA_SET_ID = "MGN-V-RDRS-5-GVDR-V1.0" DATA_SET_NAME = "MAGELLAN VENUS RADAR SYSTEM GLOBAL DATA RECORD V1.0" PRODUCT_ID = "GVTGEOM-MERC.100" MISSION_NAME = "MAGELLAN" SPACECRAFT_NAME = "MAGELLAN" INSTRUMENT_NAME = "RADAR SYSTEM" TARGET_NAME = "VENUS" ORBIT_START_NUMBER = 376 ORBIT_STOP_NUMBER = 5747 START_TIME = "N/A" STOP_TIME = "N/A" SPACECRAFT_CLOCK_START_COUNT = "N/A" SPACECRAFT_CLOCK_STOP_COUNT = "N/A" PRODUCT_CREATION_TIME = 1994-05-10T22:21:53.000 PRODUCT_RELEASE_DATE = 1994-05-13 PRODUCT_SEQUENCE_NUMBER = 00000 PRODUCT_VERSION_TYPE = "PRELIMINARY" SOURCE_DATA_SET_ID = {"MGN-V-RDRS-5-SCVDR-V1.0", "MGN-V-RDRS-CDR-ALT/RAD-V1.0"} SOURCE_PRODUCT_ID = {"SCVDR.00376-00399.1", "SCVDR.00400-00499.1","SCVDR.01100-01199.1","SCVDR.01200-01299.1", "SCVDR.01300-01399.1","SCVDR.01400-01499.1","SCVDR.01500-01599.1", "SCVDR.01600-01699.1","SCVDR.01700-01799.1","SCVDR.01800-01899.1", "SCVDR.01900-01999.1","SCVDR.02000-02099.1","SCVDR.02100-02199.1", "SCVDR.00500-00599.2","SCVDR.00600-00676.2","SCVDR.00787-00799.2", "SCVDR.00800-00899.2","SCVDR.00900-00999.2","SCVDR.01000-01099.2", "SCVDR.02200-02299.2","SCVDR.02400-02499.2","SCVDR.02500-02599.2", "SCVDR.02300-02399.1","ARCDRCD.001;2","ARCDRCD.002;1","ARCDRCD.003;1", "ARCDRCD.004;1","ARCDRCD.005;1","ARCDRCD.006;1","ARCDRCD.007;1", "ARCDRCD.008;1","ARCDRCD.009;1","ARCDRCD.010;1","ARCDRCD.011;1", "ARCDRCD.012;1","ARCDRCD.013;1","ARCDRCD.014;1","ARCDRCD.015;1", "ARCDRCD.016;1","ARCDRCD.017;1","ARCDRCD.018;1","ARCDRCD.019;1"} SOFTWARE_FLAG = "Y" PRODUCER_FULL_NAME = "Michael J. Maurer" PRODUCER_INSTITUTION_NAME = "Stanford Center for Radar Astronomy" PRODUCER_ID = "SCRA" DESCRIPTION = "This file contains the longitude and latitude values of the four corners of each tile. It is provided for convenience only, since these values can be computed from the map projection information below and the tiling information in the GVHDR file. Each row represents a single tile in the GVDR. Tiles are stored in this table in row-major, or scanline, order. The upper-left tile is stored first, then the tile to its right, and so on. The longitude and latitude values are given for the center of the pixel in each corner of the tile, so the tile actually extends one-half pixel beyond these limits." /* Data object definitions */ OBJECT = TABLE INTERCHANGE_FORMAT = ASCII ROWS = 2112 COLUMNS = 10 ROW_BYTES = 84 ^STRUCTURE = "GVTGEOM.FMT" END_OBJECT = TABLE END A.18 GVTIDX.FMT Example File DESCRIPTION = "This file describes the format of the TABLE in the GVTIDX.TAB file. See the GVTIDX.LBL file for the full PDS label." OBJECT = COLUMN NAME = PIXEL_TILE_START DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 1 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 2160640 DESCRIPTION = "The row in the GVDR_PIXEL_INDEX_TABLE containing the first pixel in this tile, with the first row numbered as 0. This will be a multiple of the number of pixels in a tile, since tiles are either written in their entirety to the pixel index file or not written at all." END_OBJECT = COLUMN OBJECT = COLUMN NAME = XIF_TILE_START DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 5 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 1896964 DESCRIPTION = "The row in the GVDR_XIF_TABLE containing the first sample of the first pixel in this tile, with the first row numbered as 0." END_OBJECT = COLUMN OBJECT = COLUMN NAME = RDF_TILE_START DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 9 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 4276931 DESCRIPTION = "The row in the GVDR_RDF_TABLE containing the first sample of the first pixel in this tile, with the first row numbered as 0." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ADF_TILE_START DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 13 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 1898257 DESCRIPTION = "The row in the GVDR_ADF_TABLE containing the first sample of the first pixel in this tile, with the first row numbered as 0." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ANF_TILE_START DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 17 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 1945746 DESCRIPTION = "The row in the GVDR_ANF_TABLE containing the first sample of the first pixel in this tile, with the first row numbered as 0." END_OBJECT = COLUMN OBJECT = COLUMN NAME = XIF_TILE_SAMPLES DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 21 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 1971 DESCRIPTION = "The number of rows in the GVDR_XIF_TABLE that correspond to pixels within this tile. The first such row is numbered XIF_TILE_START, and the last such row is numbered XIF_TILE_START + XIF_TILE_SAMPLES - 1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = RDF_TILE_SAMPLES DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 25 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 7668 DESCRIPTION = "The number of rows in the GVDR_RDF_TABLE that correspond to pixels within this tile. The first such row is numbered RDF_TILE_START, and the last such row is numbered RDF_TILE_START + RDF_TILE_SAMPLES - 1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ADF_TILE_SAMPLES DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 29 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 1024 DESCRIPTION = "The number of rows in the GVDR_ADF_TABLE that correspond to pixels within this tile. The first such row is numbered ADF_TILE_START, and the last such row is numbered ADF_TILE_START + ADF_TILE_SAMPLES - 1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ANF_TILE_SAMPLES DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 33 BYTES = 4 VALID_MINIMUM = 0 VALID_MAXIMUM = 1024 DESCRIPTION = "The number of rows in the GVDR_ANF_TABLE that correspond to pixels within this tile. The first such row is numbered ANF_TILE_START, and the last such row is numbered ANF_TILE_START + ANF_TILE_SAMPLES - 1." END_OBJECT = COLUMN A.19 GVTIDX.LBL Example File PDS_VERSION_ID = PDS3 /* File characteristics */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 36 FILE_RECORDS = 2112 /* Data object pointer */ ^TABLE = "GVTIDX.TAB" /* Identification data elements */ DATA_SET_ID = "MGN-V-RDRS-5-GVDR-V1.0" DATA_SET_NAME = "MAGELLAN VENUS RADAR SYSTEM GLOBAL DATA RECORD V1.0" PRODUCT_ID = "GVTIDX-MERC.100" MISSION_NAME = "MAGELLAN" SPACECRAFT_NAME = "MAGELLAN" INSTRUMENT_NAME = "RADAR SYSTEM" TARGET_NAME = "VENUS" ORBIT_START_NUMBER = 376 ORBIT_STOP_NUMBER = 5747 START_TIME = "N/A" STOP_TIME = "N/A" SPACECRAFT_CLOCK_START_COUNT = "N/A" SPACECRAFT_CLOCK_STOP_COUNT = "N/A" PRODUCT_CREATION_TIME = 1994-05-10T22:21:54.000 PRODUCT_RELEASE_DATE = 1994-05-13 PRODUCT_SEQUENCE_NUMBER = 00000 PRODUCT_VERSION_TYPE = "PRELIMINARY" SOURCE_DATA_SET_ID = {"MGN-V-RDRS-5-SCVDR-V1.0", "MGN-V-RDRS-CDR-ALT/RAD-V1.0"} SOURCE_PRODUCT_ID = {"SCVDR.00376-00399.1", "SCVDR.00400-00499.1","SCVDR.01100-01199.1","SCVDR.01200-01299.1", "SCVDR.01300-01399.1","SCVDR.01400-01499.1","SCVDR.01500-01599.1", "SCVDR.01600-01699.1","SCVDR.01700-01799.1","SCVDR.01800-01899.1", "SCVDR.01900-01999.1","SCVDR.02000-02099.1","SCVDR.02100-02199.1", "SCVDR.00500-00599.2","SCVDR.00600-00676.2","SCVDR.00787-00799.2", "SCVDR.00800-00899.2","SCVDR.00900-00999.2","SCVDR.01000-01099.2", "SCVDR.02200-02299.2","SCVDR.02400-02499.2","SCVDR.02500-02599.2", "SCVDR.02300-02399.1","ARCDRCD.001;2","ARCDRCD.002;1","ARCDRCD.003;1", "ARCDRCD.004;1","ARCDRCD.005;1","ARCDRCD.006;1","ARCDRCD.007;1", "ARCDRCD.008;1","ARCDRCD.009;1","ARCDRCD.010;1","ARCDRCD.011;1", "ARCDRCD.012;1","ARCDRCD.013;1","ARCDRCD.014;1","ARCDRCD.015;1", "ARCDRCD.016;1","ARCDRCD.017;1","ARCDRCD.018;1","ARCDRCD.019;1"} SOFTWARE_FLAG = "Y" PRODUCER_FULL_NAME = "Michael J. Maurer" PRODUCER_INSTITUTION_NAME = "Stanford Center for Radar Astronomy" PRODUCER_ID = "SCRA" DESCRIPTION = "This file is the tile index, the starting point of all pixel lookup operations. The description below includes a discussion of the organization of an entire GVDR image as well as instructions for use of this file. The GVDR is a pixel-based map product containing scattering properties of the surface of the planet Venus. Each pixel contains a summary of all Magellan observations of surface scattering properties. Since some pixels were observed more than once or in several modes, the amount and type of information available for each pixel is variable. The information for each pixel is stored in four separate files -- one for each unique data type. Each table has a fixed structure. Pixels observed more than once may have multiple entries in some tables; pixels never observed will not appear at all. This arrangement results in efficient storage of pixel data. In addition, solely in the interest of efficient physical access, the pixels are further organized into rectangular tiles. Within each of the four tables, all the pixels from a given tile are stored in consecutive rows. The storage order of both pixels within tiles and tiles within the entire image is row-major, or scanline format. All the pixels in the upper left tile are stored first, then all the pixels in the tile to its right, and so on. This scheme ensures that pixels located near one another on the planet are stored together in the data file. Two index files provide the row numbers of the observations corresponding to a given pixel. The GVTIDX, or tile index file, tells the rows at which each tile begins in the other files, and the GVPIDX, or pixel index file, tells where each pixel begins relative to the start of its tile. The procedure for finding all observations associated with a given pixel is the following: 1. Determine which tile the pixel belongs to using the tiling information in the GVHDR file. 2. Look up the tile in the GVTIDX file (the two-dimensional array of tiles is stored in row-major, or scanline, order). Obtain the starting rows of this tile in the other five files: GVPIDX, GVXIF, GVRDF, GVADF, and GVANF. 3. Look up the pixel in the GVPIDX file, using the row number just found in the GVTIDX file as the address of the first pixel within the tile. Within each tile, the pixels are also stored in row-major, or scanline, order. 4. The entries in the row of the GVPIDX table are the starting rows and number of rows in the four data files: GVXIF, GVRDF, GVADF and GVANF. The starting rows in the GVPIDX file are relative to the tile starting rows obtained from the GVTIDX file, so add these two numbers together. 5. Look up the rows within the data files themselves. All of this is done automatically by the software provided in the SOFTWARE directory on this volume." /* Data object definitions */ OBJECT = TABLE INTERCHANGE_FORMAT = BINARY ROWS = 2112 COLUMNS = 9 ROW_BYTES = 36 ^STRUCTURE = "GVTIDX.FMT" END_OBJECT = TABLE END A.20 GVXIF.FMT Example File DESCRIPTION = "This file describes the format of the TABLE in the GVXIF.TAB file. See the GVXIF.LBL file for the full PDS label." OBJECT = COLUMN NAME = SAMPLE_COUNT DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 1 BYTES = 2 DESCRIPTION = "The total number of image framelets used to compute the estimates of radar scattering properties given in this row of the table. The quantities given in later columns pertain only these framelets. Any framelet that is partially or completely contained inside this pixel is included. Each framelet is a slice of image data from the F-BIDR or C-BIDR files and is approximately 2 km in size along the image track. The framelets used in this row share a common observational geometry, given explicitly by the columns AZIMUTH_ANGLE, INCIDENCE_ANGLE, and POLARIZATION_ANGLE, and implicitly by the pixel address. This pixel may have entries in other rows, and if so at least one of the three angles will be different from this row." END_OBJECT = COLUMN OBJECT = COLUMN NAME = AZIMUTH_ANGLE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 3 BYTES = 2 OFFSET = 0 SCALING_FACTOR = 0.00549367 UNIT = DEGREE VALID_MINIMUM = 0 VALID_MAXIMUM = 360 DESCRIPTION = "The average azimuthal angle of the incident radiation of all image framelets used in this row. (An image framelet is a single SAR observation.) The azimuthal angle is defined in two ways, depending on the image map projection in use. For the Sinusoidal and Mercator map projections, it is defined as the local azimuth direction toward the spacecraft when viewed by an observer at the boresight intercept point on the planet surface, in degrees clockwise from North. For example, if the spacecraft appears to be due east of the observer, the azimuth angle is 90 degrees. Since this definition becomes useless near the poles, this field is set to zero above 85 degrees of latitude for the Sinusoidal projection. The Mercator projection does not extend to such high latitudes. For the Polar Stereographic map projection, the azimuth angle is expressed in the cartesian map coordinates rather than in geographic coordinates. This makes the azimuth angle more useful for interpretation because its meaning no longer varies with position. First, the azimuth direction is computed as above. Then, this direction is transformed to a direction in map coordinates; the transformed vector is parallel to the vector originating at the framelet and pointing in the azimuth direction. This vector is expressed in degrees clockwise from the +Y (up) direction on the map. For example, if the north polar projection has 0 degrees of longitude at the bottom, then a framelet at 90 degrees of longitude with a true azimuth of 90 degrees (spacecraft to the east) has a transformed azimuth of 0 degrees. The vector from the framelet to the spacecraft appears to point in the +Y direction on the map. The relationship between true azimuth and transformed azimuth is simple. For the north polar projection with 0 degrees longitude at the bottom, CARTESIAN_AZIMUTH = GEOGRAPHIC_AZIMUTH - LONGITUDE and for the south polar projection with 0 degrees longitude at the top, CARTESIAN_AZIMUTH = GEOGRAPHIC_AZIMUTH + LONGITUDE As discussed in the GVHDR.LBL file, the group of SAR observations used in this row forms a 'cohort'. Within a cohort, the azimuth angle of each observation falls within a single interval of size 360/N, where N is the value of XIF_COHORT_AZIMUTH_COUNT from the GVHDR file. We can reconstruct that interval by noting that the average azimuth angle of all the observations (given in this column) falls within the same interval. Specifically, we find a value of I that satisfies I * 360.0 / N <= AZIMUTH_ANGLE < (I+1) * 360.0 / N where N = XIF_COHORT_AZIMUTH_COUNT I = integer between 0 and N-1 inclusive The azimuth angles of all observations in the cohort lie in the interval [I*360 , (I+1)*360), and their average value is given in this column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = INCIDENCE_ANGLE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 5 BYTES = 2 OFFSET = 0 SCALING_FACTOR = 0.00137342 UNIT = DEGREE VALID_MINIMUM = 0 VALID_MAXIMUM = 90 DESCRIPTION = "The average incidence angle of the incident radiation of all image framelets used in this row. (An image framelet is a single SAR observation.) The incidence angle is the angle between the local mean surface normal (based on a pre-Magellan topography model and provided with the BIDR data) and the direction of the incoming radiation (based on geometric factors and a pre-Magellan atmospheric model of refraction, also provided with the BIDR data). Normal incidence is thus 0 degrees, and grazing incidence is 90 degrees. As discussed in the GVHDR.LBL file, the group of SAR observations used in this row forms a 'cohort'. Within a cohort, the incidence angle of each observation falls within a single interval of size 90/N, where N is the value of XIF_COHORT_INCIDENCE_COUNT from the GVHDR file. We can reconstruct that interval by noting that the average incidence angle of all the observations (given in this column) falls within the same interval. Specifically, we find a value of I that satisfies I * 90.0 / N <= INCIDENCE_ANGLE < (I+1) * 90.0 / N where N = XIF_COHORT_INCIDENCE_COUNT I = integer between 0 and N-1 inclusive The incidence angles of all observations in the cohort lie in the interval [I*90 , (I+1)*90), and their average value is given in this column." END_OBJECT = COLUMN OBJECT = COLUMN NAME = POLARIZATION_ANGLE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 6 BYTES = 1 OFFSET = -90 SCALING_FACTOR = 0.72 UNIT = DEGREE VALID_MINIMUM = -90 VALID_MAXIMUM = 90 DESCRIPTION = "The average polarization angle of the incident radiation of all image framelets used in this row. The polarization angle is defined to be +/- 90 degrees for H-H polarization (+90 is nominal for mission cycle 1) and 0 degrees for V-V polarization. Nearly all orbits maintained an almost constant H-H or V-V polarization angle; the values of 90 or 0 reported for these orbits are only nominal and are not based on actual geometric calculations. Only values that differ from 90 or 0 have been actually computed." END_OBJECT = COLUMN OBJECT = COLUMN NAME = HISTOGRAM_LOWER_KNEE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 7 BYTES = 1 DESCRIPTION = "The average DN (still to do: we should change this to absolute dB, free of Muhleman normalization) of the lower knee of the histogram of all image framelets used in this row. For each framelet, the histogram of image pixel values was computed, and the abscissa to the right of 15.87% of the pixel values was recorded. For a normal distribution, this percentile is one standard deviation below the mean; note that the pixel distribution is rarely normal and is expressed on a logarithmic abscissa. The values found for each histogram were finally averaged to form the value here." END_OBJECT = COLUMN OBJECT = COLUMN NAME = HISTOGRAM_MEDIAN DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 8 BYTES = 1 DESCRIPTION = "The average DN (we should change this to absolute dB, free of Muhleman normalization) of the median of the histogram of all image framelets used in this row. For each framelet, the histogram of image pixel values was computed, and the abscissa to the right of 50% of the pixel values was recorded. For any symmetric distribution, this value is equal to the mean; note that the pixel distribution is rarely normal and is expressed on a logarithmic abscissa. The values found for each histogram were finally averaged to form the value here." END_OBJECT = COLUMN OBJECT = COLUMN NAME = HISTOGRAM_UPPER_KNEE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 9 BYTES = 1 DESCRIPTION = "The average DN (we should change this to absolute dB, free of Muhleman normalization) of the upper knee of the histogram of all image framelets used in this row. For each framelet, the histogram of image pixel values was computed, and the abscissa to the right of 84.13% of the pixel values was recorded. For a normal distribution, this percentile is one standard deviation above the mean; note that the pixel distribution is rarely normal and is expressed on a logarithmic abscissa. The values found for each histogram were finally averaged to form the value here." END_OBJECT = COLUMN OBJECT = COLUMN NAME = HISTOGRAM_MODE DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 10 BYTES = 1 DESCRIPTION = "The average DN (we should change this to absolute dB, free of Muhleman normalization) of the mode of the histogram of all image framelets used in this row. For each framelet, the histogram of image pixel values was computed, and the abscissa with the largest number of pixel values was recorded. The values for all framelets were averaged to form the value here." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SCATTERING_LAW_CONSTANT_TERM DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 11 BYTES = 1 OFFSET = -35 SCALING_FACTOR = 0.2 UNIT = DECIBEL VALID_MINIMUM = -35 VALID_MAXIMUM = 15 DESCRIPTION = "The average radar backscatter cross-section of all image framelets used in this row. For each framelet, a quadratic polynomial has been fitted to the backscatter cross-section as a function of incidence angle. The incidence angle over any framelet only varies by 1-2 degrees, so this fit is a local one only and may be dominated by geologic features within the framelets." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SCATTERING_LAW_LINEAR_TERM DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 12 BYTES = 1 OFFSET = -5 SCALING_FACTOR = 0.04 UNIT = DECIBEL_PER_DEGREE VALID_MINIMUM = -5 VALID_MAXIMUM = 5 DESCRIPTION = "The average radar backscatter cross-section derivative of all image framelets used in this row. For each framelet, a quadratic polynomial has been fitted to the backscatter cross-section as a function of incidence angle. The incidence angle over any framelet only varies by 1-2 degrees, so this fit is a local one only and may be dominated by geologic features within the framelets." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SCATTERING_LAW_QUADRATIC_TERM DATA_TYPE = MSB_UNSIGNED_INTEGER START_BYTE = 13 BYTES = 1 OFFSET = -15 SCALING_FACTOR = 0.12 UNIT = DECIBEL_PER_DEGREE_SQUARED VALID_MINIMUM = -15 VALID_MAXIMUM = 15 DESCRIPTION = "The average radar backscatter cross-section second derivative of all image framelets used in this row. For each framelet, a quadratic polynomial has been fitted to the backscatter cross-section as a function of incidence angle. The incidence angle over any framelet only varies by 1-2 degrees, so this fit is a local one only and may be dominated by geologic features within the framelets." END_OBJECT = COLUMN A.21 GVXIF.LBL Example File PDS_VERSION_ID = PDS3 /* File characteristics */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 14 FILE_RECORDS = 1897076 /* Data object pointer */ ^TABLE = "GVXIF.TAB" /* Identification data elements */ DATA_SET_ID = "MGN-V-RDRS-5-GVDR-V1.0" DATA_SET_NAME = "MAGELLAN VENUS RADAR SYSTEM GLOBAL DATA RECORD V1.0" PRODUCT_ID = "GVXIF-MERC.100" MISSION_NAME = "MAGELLAN" SPACECRAFT_NAME = "MAGELLAN" INSTRUMENT_NAME = "RADAR SYSTEM" TARGET_NAME = "VENUS" ORBIT_START_NUMBER = 376 ORBIT_STOP_NUMBER = 2599 START_TIME = "N/A" STOP_TIME = "N/A" SPACECRAFT_CLOCK_START_COUNT = "N/A" SPACECRAFT_CLOCK_STOP_COUNT = "N/A" PRODUCT_CREATION_TIME = 1994-05-10T22:21:58.000 PRODUCT_RELEASE_DATE = 1994-05-13 PRODUCT_SEQUENCE_NUMBER = 00000 PRODUCT_VERSION_TYPE = "PRELIMINARY" SOURCE_DATA_SET_ID = {"MGN-V-RDRS-5-SCVDR-V1.0"} SOURCE_PRODUCT_ID = {"SCVDR.00376-00399.1", "SCVDR.00400-00499.1","SCVDR.01100-01199.1","SCVDR.01200-01299.1", "SCVDR.01300-01399.1","SCVDR.01400-01499.1","SCVDR.01500-01599.1", "SCVDR.01600-01699.1","SCVDR.01700-01799.1","SCVDR.01800-01899.1", "SCVDR.01900-01999.1","SCVDR.02000-02099.1","SCVDR.02100-02199.1", "SCVDR.00500-00599.2","SCVDR.00600-00676.2","SCVDR.00787-00799.2", "SCVDR.00800-00899.2","SCVDR.00900-00999.2","SCVDR.01000-01099.2", "SCVDR.02200-02299.2","SCVDR.02400-02499.2","SCVDR.02500-02599.2", "SCVDR.02300-02399.1"} SOFTWARE_FLAG = "Y" PRODUCER_FULL_NAME = "Michael J. Maurer" PRODUCER_INSTITUTION_NAME = "Stanford Center for Radar Astronomy" PRODUCER_ID = "SCRA" DESCRIPTION = "The GVXIF file contains statistical measures of the surface's scattering properties derived from the side-looking synthetic aperture radar images. (The XIF acronym is a combination of 'Sinusoidal Image File', or SIF, and 'Oblique sinusoidal Image File, or OIF, two of the data files in the SCVDR data product.) This file is a table; each row in the table summarizes XIF results in a particular SAR viewing geometry. The location and number of rows associated with each pixel are given by the corresponding values of XIF_START and XIF_SAMPLES in GVPIDX.TAB. See the descriptions in the GVTIDX.LBL and GVPIDX.LBL files for the overall organization of the GVDR. These files describe the division of the planet into pixels and organization of pixels into rectangular tiles." /* Data object definitions */ OBJECT = TABLE INTERCHANGE_FORMAT = BINARY ROWS = 1897076 COLUMNS = 11 ROW_BYTES = 14 ^STRUCTURE = "GVXIF.FMT" END_OBJECT = TABLE END A.22 INDEX.FMT Example File DESCRIPTION = "This file describes the format of the TABLE in the INDEX.TAB file. See the INDEX.LBL file for the full PDS label." OBJECT = COLUMN NAME = VOLUME_ID DATA_TYPE = CHARACTER START_BYTE = 2 BYTES = 9 DESCRIPTION = "The volume identification string of the volume containing the data file referred to in GVDR_FILE_NAME." END_OBJECT = COLUMN OBJECT = COLUMN NAME = DATA_SET_ID DATA_TYPE = CHARACTER START_BYTE = 14 BYTES = 22 DESCRIPTION = "The data set identification string of the data set containing the data file referred to in GVDR_FILE_NAME." END_OBJECT = COLUMN OBJECT = COLUMN NAME = PRODUCT_ID DATA_TYPE = CHARACTER START_BYTE = 39 BYTES = 18 DESCRIPTION = "The product identification string associated with the data file referred to in GVDR_FILE_NAME." END_OBJECT = COLUMN OBJECT = COLUMN NAME = GVDR_DIRECTORY_NAME DATA_TYPE = CHARACTER START_BYTE = 60 BYTES = 13 DESCRIPTION = "The name of the directory containing the data file, including all directories from the root level. The directories are specified with Unix-style pathnames (without the leading slash), e.g. 'DIR/SUBDIR'." END_OBJECT = COLUMN OBJECT = COLUMN NAME = GVDR_FILE_NAME DATA_TYPE = CHARACTER START_BYTE = 76 BYTES = 12 DESCRIPTION = "The name of the data file, omitting the directory specification, e.g. 'GVHDR.TAB'." END_OBJECT = COLUMN A.23 INDEX.LBL Example File PDS_VERSION_ID = PDS3 /* File characteristics */ RECORD_TYPE = FIXED_LENGTH RECORD_BYTES = 90 FILE_RECORDS = 10 /* Data object pointer */ ^TABLE = "INDEX.TAB" /* Identification data elements */ DATA_SET_ID = "MGN-V-RDRS-5-GVDR-V1.0" DATA_SET_NAME = "MAGELLAN VENUS RADAR SYSTEM GLOBAL DATA RECORD V1.0" PRODUCT_ID = "INDEX-MERC.100" MISSION_NAME = "MAGELLAN" SPACECRAFT_NAME = "MAGELLAN" INSTRUMENT_NAME = "RADAR SYSTEM" TARGET_NAME = "VENUS" ORBIT_START_NUMBER = 376 ORBIT_STOP_NUMBER = 5747 START_TIME = "N/A" STOP_TIME = "N/A" SPACECRAFT_CLOCK_START_COUNT = "N/A" SPACECRAFT_CLOCK_STOP_COUNT = "N/A" PRODUCT_CREATION_TIME = 1994-05-10T22:21:38.000 PRODUCT_RELEASE_DATE = 1994-05-13 PRODUCT_SEQUENCE_NUMBER = 00000 PRODUCT_VERSION_TYPE = "PRELIMINARY" SOURCE_DATA_SET_ID = {"MGN-V-RDRS-5-SCVDR-V1.0", "MGN-V-RDRS-CDR-ALT/RAD-V1.0"} SOURCE_PRODUCT_ID = {"SCVDR.00376-00399.1", "SCVDR.00400-00499.1","SCVDR.01100-01199.1","SCVDR.01200-01299.1", "SCVDR.01300-01399.1","SCVDR.01400-01499.1","SCVDR.01500-01599.1", "SCVDR.01600-01699.1","SCVDR.01700-01799.1","SCVDR.01800-01899.1", "SCVDR.01900-01999.1","SCVDR.02000-02099.1","SCVDR.02100-02199.1", "SCVDR.00500-00599.2","SCVDR.00600-00676.2","SCVDR.00787-00799.2", "SCVDR.00800-00899.2","SCVDR.00900-00999.2","SCVDR.01000-01099.2", "SCVDR.02200-02299.2","SCVDR.02400-02499.2","SCVDR.02500-02599.2", "SCVDR.02300-02399.1","ARCDRCD.001;2","ARCDRCD.002;1","ARCDRCD.003;1", "ARCDRCD.004;1","ARCDRCD.005;1","ARCDRCD.006;1","ARCDRCD.007;1", "ARCDRCD.008;1","ARCDRCD.009;1","ARCDRCD.010;1","ARCDRCD.011;1", "ARCDRCD.012;1","ARCDRCD.013;1","ARCDRCD.014;1","ARCDRCD.015;1", "ARCDRCD.016;1","ARCDRCD.017;1","ARCDRCD.018;1","ARCDRCD.019;1"} SOFTWARE_FLAG = "Y" PRODUCER_FULL_NAME = "Michael J. Maurer" PRODUCER_INSTITUTION_NAME = "Stanford Center for Radar Astronomy" PRODUCER_ID = "SCRA" DESCRIPTION = "This file is an index of all data files on this volume. Each instance of a unique PRODUCT_ID occupies one row of this table." /* Data object definitions */ OBJECT = TABLE INTERCHANGE_FORMAT = ASCII ROWS = 10 COLUMNS = 5 ROW_BYTES = 90 ^STRUCTURE = "INDEX.FMT" END_OBJECT = TABLE END