TABLE OF CONTENTS

1. Introduction................................................................................................................................. 1

1.1. Purpose and Scope............................................................................................................... 1

1.2. Content Overview................................................................................................................ 1

1.3. Applicable Documents and Constraints............................................................................... 1

2. Archive Volume Contents........................................................................................................... 1

2.1. Root Directory Contents...................................................................................................... 1

2.2. Calib Directory Contents..................................................................................................... 2

2.3. Catalog Directory Contents................................................................................................. 2

2.4. Data Directory Contents and Naming................................................................................. 2

2.5. Document Directory Contents............................................................................................. 4

2.6. Extras Directory Contents................................................................................................... 5

2.7. Index Directory Contents.................................................................................................... 5

3. Archive Volume Format.............................................................................................................. 6

3.1. Volume Format.................................................................................................................... 6

3.2. File Formats......................................................................................................................... 6

3.2.1. Document File Format............................................................................................... 6

3.2.2. Tabular File Format................................................................................................... 7

3.2.3. PDS Label Format..................................................................................................... 7

3.2.4. Catalog File Format................................................................................................... 7

3.2.5. Science Data File Formats......................................................................................... 8

4. Archive Volume Generation........................................................................................................ 9

4.1. Data Transfer and Validation Methods............................................................................... 9

4.2. Data Product Sizes and Delivery Rates............................................................................... 9

4.3. Interface Media Characteristics........................................................................................... 9

4.4. Labeling and Identification................................................................................................. 9

5. Support Staff and Cognizant Persons......................................................................................... 9

TABLES AND FIGURES

Table 2-1. NASA Definition of Processing Levels for Science Data Sets...................................... 3

Table 2-2. Index Table Contents..................................................................................................... 5

DOCUMENT CHANGE LOG

Change	Date	Affected Portions

TBD ITEMS

Section	Description

ACRONYMS AND ABBREVIATIONS

ASCII	American Standard Code for Information Interchange
CD-ROM	Compact Disk - Read-Only Memory
CD-WO	Write-Once Compact Disk
DDR	Derived Data Record
EDR	Experiment Data Record
ISO	International Standards Organization
JPL	Jet Propulsion Laboratory
LRO	Lunar Reconnaissance Orbiter
NSSDC	National Space Science Data Center
PDS	Planetary Data System
RDR	Reduced Data Record
SIS	Software Interface Specification
TBD	To Be Determined

GLOSSARY

Archive – An archive consists of one or more data sets along with all the documentation and ancillary information needed to understand and use the data. An archive is a logical construct independent of the medium on which it is stored.

Archive Volume, Archive Volume Set – A volume is a unit of media on which data products are stored; for example, one CD-ROM or DVD-ROM. An archive volume is a volume containing all or part of an archive; that is, data products plus documentation and ancillary files. When an archive spans multiple volumes, they are called an archive volume set. Usually the documentation and some ancillary files are repeated on each volume of the set, so that a single volume can be used alone.

Catalog Information – Descriptive information about a data set (e.g. mission description, spacecraft description, instrument description), expressed in Object Description Language (ODL) which is suitable for loading into a PDS catalog.

Data Product – A labeled grouping of data resulting from a scientific observation, usually stored in one file. A product label identifies, describes, and defines the structure of the data. An example of a data product is a planetary image, a spectrum table, or a time series table.

Data Set – An accumulation of data products. A data set together with supporting documentation and ancillary files is an archive.

Standard Data Product – A data product generated in a predefined way using well-understood procedures, processed in "pipeline" fashion. Data products that are generated in a nonstandard way are sometimes called special data products.

1. Introduction

1.1. Purpose and Scope

This Software Interface Specification is intended to be used by those who wish to understand the format and content of the Lunar Reconnaissance Orbiter (LRO) Mini-RF Bistatic Radar Archive. Typically, these individuals would be software engineers, data analysts, or planetary scientists.

1.2. Content Overview

This Software Interface Specification (SIS) describes the format, content, and generation of the LRO Mini-RF Bistatic Radar Archive. Section 2, Archive Volume Generation, describes the procedure for transferring data products to archive media. Section 3, Archive Volume Contents, describes the structure of the archive volumes and the contents of each file. Section 4, Archive Volume Format, describes the file formats used on the archive volumes. Finally, Section 5, Support Staff and Cognizant Persons, lists the individuals responsible for generating the archive volumes.

1.3. Applicable Documents and Constraints

This Archive Volume SIS is intended to be consistent with the following documents:

1. Lunar Reconnaissance Orbiter Project Data Management and Archive Plan, 431-PLAN-00182.

2. "Quick-look at bistatic SAR data collected on April 6, 2011", Jensen, J.R., and R.C. Schulze, April 13, 2011, BISTATIC.PDF in the Document directory of this archive.

3. PDS Data Product Software Interface Specification (SIS) for Mini-RF, MRF-4089, February 25, 2010, MRFLRO_DP_SIS.PDF in the Document directory of this archive.

Planetary Data System Archive Preparation Guide, April 1, 2010, Version 1.4, JPL D-31224.
Planetary Data System Standards Reference, February 27, 2009, Version 3.8. JPL D-7669, Part 2.

2. Archive Volume Contents

This section describes the contents of the Mini-RF Bistatic Radar Archive, including the file names, file contents, file types, and organization responsible for providing the files.

2.1. Root Directory Contents

Files in the Root Directory include an overview of the archive, a description of the volume for the PDS Catalog, and a list of errata or comments about the archive. The following files are contained in the Root Directory.

File Name	File Contents	File Provided By
AAREADME.TXT	Volume content and format information	Mini-RF Team
ERRATA.TXT	A cumulative listing of comments and updates concerning all archive volumes published to date	Mini-RF Team
VOLDESC.CAT	A description of the contents of this volume in a PDS format readable by both humans and computers	Geosciences Node

2.2. Calib Directory Contents

The Calib Directory contains calibration files used to process the data products, or calibration data needed to use the data products. The following files are contained in the Calib Directory.

File Name	File Contents	File Provided By
CALINFO.TXT	A description of the contents of this directory	Geosciences Node
BISTATIC_PROC_CALIB.PDF	Bistatic radar calibration document	Mini-RF Team
BISTATIC_PROC_CALIB.LBL	PDS label for BISTATIC_PROC_CALIB.PDF	Mini-RF Team
MINIRF_CALIBRATION.PDF	Mini-RF calibration document	Mini-RF Team
MINIRF_CALIBRATION.LBL	PDS label for MINIRF_CALIBRATION.PDF	Mini-RF Team

2.3. Catalog Directory Contents

The files in the Catalog Directory provide a top-level understanding of the mission, spacecraft, instruments, and data sets. The files in this directory are coordinated with the PDS data engineer, who is responsible for loading them into the PDS catalog. The following files are found in the Catalog Directory.

File Name	File Contents	File Provided By
CATINFO.TXT	A description of the contents of this directory	Geosciences Node
MRFLRO_235_BISTATIC_DS.CAT	Data set information for the PDS catalog	Mini-RF Team
LRO_INSTHOST.CAT	Instrument host (i.e., spacecraft) information for the PDS catalog	LRO Project
MRF_INST.CAT	Instrument information for the PDS catalog	Mini-RF Team
LRO_MISSION.CAT	Mission information for the PDS catalog	LRO Project
MRF_PERSON.CAT	Personnel information for the PDS catalog (Team and PDS personnel responsible for generating the archive)	Mini-RF Team
MRF_REF.CAT	References mentioned in other *.CAT files	Mini-RF Team

2.4. Data Directory Contents and Naming

The Mini-RF Bistatic Radar archive includes data processed at CODMAC level 2 (EDR), level 3 (DDR), and level 5 (RDR). See Table 2-1 for processing level definitions.

Table 2-1. NASA Definition of Processing Levels for Science Data Sets

NASA	CODMAC	Description
Packet data	Raw - Level 1	Telemetry data stream as received at the ground station, with science and engineering data embedded.
Level-0	Edited - Level 2	Instrument science data (e.g., raw voltages, counts) at full resolution, time ordered, with duplicates and transmission errors removed.
Level 1-A	Calibrated - Level 3	Level 0 data that have been located in space and may have been transformed (e.g., calibrated, rearranged) in a reversible manner and packaged with needed ancillary and auxiliary data (e.g., radiances with the calibration equations applied).
Level 1-B	Resampled - Level 4	Irreversibly transformed (e.g., resampled, remapped, calibrated) values of the instrument measurements (e.g., radiances, magnetic field strength).
Level 1C	Derived - Level 5	Level 1A or 1B data that have been resampled and mapped onto uniform space-time grids. The data are calibrated (i.e., radiometrically corrected) and may have additional corrections applied (e.g., terrain correction).
Level 2	Derived - Level 5	Geophysical parameters, generally derived from Level 1 data, and located in space and time commensurate with instrument location, pointing, and sampling.
Level 3	Derived - Level 5	Geophysical parameters mapped onto uniform space-time grids.
	Ancillary data – Level 6	Nonscience data needed to generate calibrated or resampled data sets. Consists of instrument gains, offsets; pointing information for scan platforms, etc.

The data products are found in the archive subdirectories DATA/EDR, DATA/DDR, and DATA/RDR. File names follow this naming scheme:

LST_nnnnn_mpp_XIU_aahddd_Vz.ext

where

L indicates LRO,

S indicates S-band (always the case for these products),

T indicates bistatic product,

nnnnn is the orbit number,

m is 0 for EDRs, 1 for DDRs and RDRs,

pp is the product type,

HR for horizontal real

VR for vertical real

HI for horizontal imaginary

VI for vertical imaginary

DD for derived data

S1, S2, S3, S4 for Stokes parameters S1 - S4,

CP for circular polarization ratio

X indicates no map projection (always the case for these products),

I indicates pixel resolution of 118 m/pixel which is close to the 100 m/pixel resolution of the bistatic images. See Table 16 in the Mini-RF Data Product SIS (Applicable Document 3) for a description of these letter codes.

U indicates a data type of regular real number,

aa is the lunar latitude of the center of the bistatic image, range 0 to 90 degrees,

h is the hemisphere of the latitude, N for northern latitude or S for southern latitude,

ddd is the lunar longitude of the center of the bistatic image range 0 to 359 degrees,

z is the product version number,

ext is IMG for an image file or LBL for a PDS label file.

2.5. Document Directory Contents

The Document Directory contains documentation to help the user understand and use the archive data. The following files are contained in the Document Directory.

File Name	File Contents	File Provided By
DOCINFO.TXT	A description of the contents of this directory	Geosciences Node
BISTATIC.PDF	Mini-RF team memorandum that describes the collection of the raw bistatic data products	Mini-RF Team
BISTATIC.HTM	A hypertext version of BISTATIC.PDF	Mini-RF Team
BISTATIC.LBL	A PDS label that describes both BISTATIC.PDF and BISTATIC.HTM	Mini-RF Team
BISTATIC_IMAGES	Subdirectory containing images linked from BISTATIC.HTM	Mini-RF Team
MRFLRO_DP_SIS.PDF	The original Mini-RF Data Product SIS as a PDF file. This document does not describe the bistatic products, but it does describe the standard Mini-RF products and includes background information about Mini-RF.	Mini-RF Team
MRFLRO_DP_SIS.HTM	The original Mini-RF Data Product SIS as hypertext	Mini-RF Team
MRFLRO_DP_SIS.LBL	A PDS label that describes both DPSIS.HTM and DPSIS.PDF	Mini-RF Team
IMAGES	Subdirectory containing images linked from MRFLRO_DP_SIS.HTM	Mini-RF Team
ARCHSIS.PDF	The Archive Volume SIS (this document) as a PDF file	Geosciences Node
ARCHSIS.HTM	The Archive Volume SIS (this document) as hypertext	Geosciences Node
ARCHSIS.LBL	A PDS label that describes both ARCHSIS.HTM and ARCHSIS.PDF.	Geosciences Node

2.6. Extras Directory Contents

The Extras Directory contains documentation, utility programs, or other materials that the user may find helpful, but that are beyond the scope of the required elements of the archive. The contents of this directory are exempt from PDS requirements for labeling. The Extras Directory is intended for "value-added" material, handy to have but not crucial for understanding the data. The following files are contained in the Extras Directory.

File Name	File Contents	File Provided By
EXTRINFO.TXT	A description of the contents of this directory	Mini-RF Team
*.JPG	Quick-look JPEG images of the radar collection sites	Mini-RF Team

2.7. Index Directory Contents

Files in the Index Directory are provided to help the user locate products in the archive. The following files are contained in the Index Directory.

File Name	File Contents	File Provided By
INDXINFO.TXT	A description of the contents of this directory	Geosciences Node
INDEX.TAB	A table listing all data products on this volume	Geosciences Node
INDEX.LBL	A PDS detached label that describes INDEX.TAB	Geosciences Node

The index table contains one row for each product. Table 2-2 lists the columns of the index table.

Table 2-2. Index Table Contents

Column Name	Description	Source
VOLUME_ID	PDS archive volume on which a data product is stored	Specified at time of index table creation
DATA_SET_ID	PDS unique identifier of the data set to which a data product belongs	Assigned by PDS
PRODUCT_ID	Unique identifier for data product	PDS label
PRODUCT_TYPE	Type of EDR product, e.g. ENGEDR, SCEDR, EGAEDR, etc.	PDS label
PRODUCT_VERSION_ID	Version number of data product	PDS label
FILE_SPECIFICATION_NAME	Directory path and file name of label file for data product, relative to volume root	PDS label file name
PRODUCT_CREATION_TIME	Date and time of data product creation	PDS label
START_TIME	UTC date and time of start of observation	PDS label
STOP_TIME	UTC date and time of end of observation	PDS label
ORBIT_NUMBER	LRO orbit number	PDS label
INCIDENCE_ANGLE	Radar incidence angle measured from surface normal	PDS label
EMISSION_ANGLE	Radar emission angle measured from surface normal	PDS label
PHASE_ANGLE	Angle between incident radar vector and return radar vector	PDS label
LOOK_AZIMUTH_ANGLE	Look angle value from 0 to 360, where 0 = north-looking, 90 = east-looking, 180 = south-looking, and 270 = west-looking	PDS label
LOOK_DIRECTION	The side of the spacecraft ground track to which the SAR antenna was pointed, LEFT or RIGHT	PDS label

3. Archive Volume Format

This section describes the formats used in the Mini-RF Bistatic Radar Archive. Data that comprise the Archive are formatted in accordance with Planetary Data System specifications [Applicable Documents 4 and 5].

3.1. Volume Format

The Mini-RF Bistatic Radar archive is stored as a single PDS 3 standard archive volume with the volume ID USA_NASA_JPL_LROMRF_2XXX [Applicable Document 5]. As new data become available they are added to the existing volume. The archive is maintained online by the PDS Geosciences Node with redundant backup copies stored offline.

3.2. File Formats

This section describes file formats.

3.2.1. Document File Format

Document files with the .TXT extension are ASCII text files, which may have embedded PDS labels. Lines in a .TXT file end with a carriage return character (ASCII 13) and a line feed character (ASCII 10). This allows the files to be readable under various operating systems.

Documents in the Document directory may contain formatting and figures that cannot be rendered as ASCII text. Therefore each document is given in two formats, hypertext and PDF. The hypertext file contains ASCII text plus hypertext markup language (HTML) commands that enable it to be viewed in a Web browser. The hypertext file may be accompanied by ancillary files such as images and style sheets that are incorporated into the document by the Web browser. The second format, PDF (Portable Document Format) is frequently used for publications that contain figures and special formatting. Free software for viewing PDF files is available from various sources online, e.g. http://get.adobe.com/reader/.

3.2.2. Tabular File Format

Tabular files (.TAB suffix) exist in the Index directory. Tabular files are ASCII files formatted for direct reading into many database management systems on various computers. All fields are separated by commas, and character fields are enclosed in double quotation marks ("). (Character fields 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 are of 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 don't.

All TAB files are described by PDS labels in a separate file with the same name as the data file it describes, but with the extension .LBL. For example, the file INDEX.TAB is accompanied by the detached label file INDEX.LBL in the same directory.

3.2.3. PDS Label Format

All data files in the archive have PDS labels, either embedded at the beginning of the file or detached in a separate file.

A PDS label, whether embedded or detached from its associated file, consists of lines of ASCII text in the form of keyword = value statements that provide descriptive information about the data file. The label is intended to be readable both by humans and by software. Details of the syntax and semantics of PDS labels can be found in the PDS Standards Reference (Applicable Document 5), and definitions of the keywords used in the label can be found by using the PDS Data Dictionary Lookup web service at http://pds.jpl.nasa.gov/tools/ddlookup/data_dictionary_lookup.cfm.

Lines of text in detached labels end with a carriage return character (ASCII 13) and a line feed character (ASCII 10). This allows the files to be read under various operating systems.

3.2.4. Catalog File Format

Catalog files (suffix .CAT) exist in the Root and Catalog directories. Like PDS labels, they are text files formatted as keyword = value statements. They contain descriptions of the data set, instrument, spacecraft, and mission, as well as personnel contact information and references to published literature. They are called Catalog Files because they are loaded into the PDS online catalog to make the information available to users searching for data.

3.2.5. Science Data File Formats

The data are images in standard PDS image format. They are stored as simple binary arrays of 4-byte floating-point pixels without any embedded headers. Each image is described by its accompanying PDS label in a file with the same name as the image but with the extension LBL. The label gives details about the content and format of the image. EDR and RDR products are single-band images. DDR products have multiple bands containing latitude, longitude, phase angle, incidence angle, emission angle, and range data.

More information about the bistatic radar products can be found in the data set description information for the PDS catalog, MRFLRO_235_BISTATIC_DS.CAT in the Catalog directory of this archive.

4. Archive Volume Generation

4.1. Data Transfer and Validation Methods

Mini-RF Bistatic Radar products are generated by the Mini-RF team whenever a bistatic observation opportunity produces archive quality data. These opportunities occur infrequently and not on a regular schedule.

4.2. Data Product Sizes and Delivery Rates

A typical bistatic radar observation results in four EDR products, one DDR product, and five RDR products. The set may range in size from about one GB to eight or nine GB. As the deliveries occur at irregular intervals, it is not possible to predict a delivery rate.

4.3. Interface Media Characteristics

All volumes in the Mini-RF Bistatic Radar Standard Product Archive conform to ISO 9660 standards [ISO 9660, 1988].

4.4. Labeling and Identification

The Mini-RF Bistatic Radar archive is stored on single PDS archive volume with the volume ID USA_NASA_JPL_LROMRF_2XXX.

5. Support Staff and Cognizant Persons

Dr. D. Ben Bussey
Principal Investigator
Johns Hopkins University Applied Physics Laboratory
11100 Johns Hopkins Rd.
Laurel, MD 20723-6099
Ben.Bussey@jhuapl.edu

Dr. G. Wesley Patterson
Data Producer
Johns Hopkins University Applied Physics Laboratory
11100 Johns Hopkins Road
Laurel, MD 20723-6099
Wes.Patterson@jhuapl.edu

Ms. Helene Winters
Johns Hopkins University Applied Physics Laboratory
11100 Johns Hopkins Rd.
Laurel, MD 20723-6099
Helene.Winters@jhuapl.edu

Mr. Michael Reid
Johns Hopkins University Applied Physics Laboratory
11100 Johns Hopkins Rd.
Laurel, MD 20723-6099
Mike.Reid@jhuapl.edu

Ms. Susan Slavney
PDS Geosciences Node
Washington University
1 Brookings Drive, Campus Box 1169
St. Louis, MO 63130
Susan.Slavney@wustl.edu