The Mars Global Surveyor MOLA PEDR Archive

(AAREADME.HTM)

February 27, 2003


  1. Introduction
  2. Documentation
  3. Notes and Caveats
  4. File Formats
  5. Volume Contents
  6. Whom To Contact For Information
  7. Cognizant Persons
  8. Citations

1. Introduction

This document provides an overview of the Mars Global Surveyor MOLA PEDR Archive, including a complete listing of the contents of the archive, below.

This archive contains science data products from observations acquired by the Mars Global Surveyor (MGS) Mars Orbiter Laser Altimeter (MOLA) instrument during the Mapping Phase of the mission.

MOLA data products include Aggregated Experiment Data Records, or AEDRs (raw data), Precision Experiment Data Records, or PEDRs (data from AEDRs with precision orbit corrections applied), and Experiment Gridded Data Records, or EGDRs (gridded products derived from PEDRs). This volume contains PEDRs.

2. Documentation

The PEDR data set is described in the file PEDRDS.CAT in the CATALOG directory. Also in this directory are files describing the MOLA instrument (INST.CAT), the MGS spacecraft (INSTHOST.CAT) and mission (MISSION.CAT), personnel associated with this archive volume (PERSON.CAT), and a bibliography of references mentioned in these files (REF.CAT). The files in this directory are entries in the Planetary Data System online catalog.

Additional documentation is found in the DOCUMENT directory, including Software Interface Specification (SIS) documents for the PEDR data set (PEDRSIS.HTM) and for the PEDR archive volumes (ARCHSIS.HTM). A description of calibration procedures applied to MOLA data is also given.

3. Notes and Caveats

MOLA data products are identified by orbit number in the file name and in the product ID found in the label. MOLA products from the Orbit Insertion Phase of the mission contain one orbit per file. Mapping Phase products are aggregated by day, so that one file contains several orbits. For Mapping Phase products, the orbit number in the file name and the product ID refers to the first orbit covered by that product. (Note: subtract 10000 from a MOLA mapping phase orbit number to determine the equivalent MGS Project orbit number.)

4. File Formats

PEDRs are binary files with attached PDS labels. The format of these files is described in the PEDR Software Interface Specification (SIS) document in the DOCUMENT directory. Additional information about PDS labels is found in the Planetary Data System Standards Reference, version 3.5, October 30, 2002, JPL D-7669.

All text files on this volume are stream format files, with a carriage return (ASCII 13) and a line feed character (ASCII 10) at the end of the record. This allows the files to be read by the MacOS, DOS, and UNIX operating systems. The SIS documents in the DOCUMENT directory are given as hypertext (HTML), which can be viewed with a Web browser, and in the proprietary Adobe Portable Document Format (PDF), which can be viewed with the free software Acrobat Reader from Adobe Systems Incorporated.

5. Volume Contents

Files on this volume are organized into a series of subdirectories below the top-level directory. The following table shows the structure and content of these directories. In the table, directory names are enclosed in square brackets ([]).

      FILE                  CONTENTS

  Top-level directory
   |
   |- AAREADME.TXT          Plain text version of AAREADME.HTM.
   |- AAREADME.HTM          The file you are reading.
   |- AAREADME.LBL          PDS label for both AAREADME files.
   |- ERRATA.TXT            Comments and errata on this volume.
   |- VOLDESC.CAT           Description of the contents of this CD-ROM
   |                        volume in object format.
   |
   |- [CATALOG]             PDS catalog objects.
   |   |- CATINFO.TXT       Description of files in the CATALOG directory.
   |   |- INST.CAT          Description of the MOLA instrument.
   |   |- INSTHOST.CAT      Description of the MGS spacecraft.
   |   |- MISSION.CAT       Description of the MGS mission.
   |   |- PEDRDS.CAT        Description of PEDR data set.
   |   |- PERSON.CAT        Description of personnel associated with
   |   |                      production of this volume.
   |   |- REF.CAT           Reference objects mentioned in *.CAT files.
   |
   |- [DATA]
   |   |- [APnnXXX]         PEDR data directory, where nn represents a
   |       |                  group of 1000 orbits. For example, AP12XXX
   |       |                  includes data from orbits 12000 to 12999. 
   |       |- APnnnnnL.B    PEDR data files, where nnnnn = orbit number.
   |                          The MOLA orbit number is equal to the MGS
   |                          Project orbit number plus 10000, for 
   |                          Mapping Phase products. 
   |    
   |
   |- [DOCUMENT]            Documentation files.
   |   |- ARCHSIS.HTM       MOLA Archive Volume SIS.
   |   |- ARCHSIS.LBL       PDS label for ARCHSIS.HTM and ARCHSIS.PDF.
   |   |- ARCHSIS.PDF       MOLA Archive Volume SIS in Adobe Portable
   |   |                      Document Format.
   |   |- CALFIGS.LBL       PDS label for CALFIGS.PDF.
   |   |- CALFIGS.PDF       Figures to accompany CALIB.PDF.
   |   |- CALIB.LBL         PDS label for CALIB.PDF.
   |   |- CALIB.PDF         MOLA calibration document.
   |   |- DOCINFO.TXT       Description of files in DOCUMENT directory.
   |   |- FIGURE1.GIF       Figure 1 used in ARCHSIS.HTM.
   |   |- PEDRSIS.HTM       MOLA PEDR SIS.
   |   |- PEDRSIS.LBL       PDS label for PEDRSIS.HTM and PEDRSIS.PDF.
   |   |- PEDRSIS.PDF       MOLA PEDR SIS in Adobe Portable Document
   |                          Format.
   |   
   |- [INDEX]               Index files.
   |   |- INDXINFO.TXT      Description of files in the INDEX directory.
   |   |- INDEX.LBL         PDS label for INDEX.TAB.
   |   |- INDEX.TAB         Index table of PEDR products on this volume.
   |
   |- [LABEL]               Format files referenced by data product labels.
   |   |- LABINFO.TXT       Description of files in the LABEL directory.
   |   |- PEDRENGn.FMT      Describes the format of the second section
   |   |                      of a PEDR, where n=1 through 7. Seven
   |   |                      different record formats are possible,
   |   |                      depending on which of seven frames is
   |   |                      recorded.
   |   |- PEDRSEC1.FMT      Describes the format of the first section
   |   |                      of a PEDR.
   |   |- PEDRSEC3.FMT      Describes the format of the third section
   |                          of a PEDR.
   |
   |- [SOFTWARE]            Software for accessing PEDR files.
       |- SOFTINFO.TXT      Description of files in SOFTWARE directory.
       |
       |- [MPROF]           Directory containing MPROF software to
       |   |                  generate PEDR topography profiles.
       |   |
       |   |- MPRFINFO.TXT  Instructions for using MPROF.PRO.
       |   |- MPROF.PRO     PC/Windows version of IDL script.
       |
       |- [PEDR2TAB]        Directory containing PEDR2TAB software
       |   |                  to generate PEDR ASCII tables.
       |   |
       |   |- [MAC]         Directory containing Macintosh version.
       |   |   |- MOLA.LBL      Example PDS label for PEDR2TAB output.
       |   |   |- P2TABPPC.HQX  BINHEX file containing executable
       |   |   |                  program compiled for PowerPC.
       |   |   |- P2TINFO.TXT   Instructions for using PEDR2TAB.
       |   |   |- PEDR2TAB.F    Fortran 77 source code for Macintosh.
       |   |   |- PEDR2TAB.PRM  Preferences file to be edited by user.
       |   |
       |   |- [PC]          Directory containing PC/Windows version.
       |   |   |- MOLA.LBL      Example PDS label for PEDR2TAB output.
       |   |   |- P2TINFO.TXT   Instructions for using PEDR2TAB.
       |   |   |- PEDR2TAB.EXE  Executable file compiled for MS-DOS.
       |   |   |- PEDR2TAB.F    Fortran 77 source code for PC/Windows.
       |   |   |- PEDR2TAB.PRM  Preferences file to be edited by user.
       |   |
       |   |- [SUN]         Directory containing Sun/UNIX version.
       |       |- MOLA.LBL      Example PDS label for PEDR2TAB output.
       |       |- P2TINFO.TXT   Instructions for using PEDR2TAB.
       |       |- PEDR2TAB.EXE  Executable file compiled for Solaris 2.4.
       |       |- PEDR2TAB.F    Fortran 77 source code for Sun/UNIX.
       |       |- PEDR2TAB.PRM  Preferences file to be edited by user.
       |
       |- [SPLITORB]        Directory containing SPLITORB software
           |                  to separate a PEDR into single orbits.
           |
           |- SPLTINFO.TXT  Instructions for using SPLITORB.PRO.
           |- SPLITORB.PRO  Script for use with UNIX or PC versions
                              of IDL.

6. Whom To Contact For Information

For questions concerning this data set collection:

PDS Geosciences Node
Washington University
Dept. of Earth and Planetary Sciences
1 Brookings Drive
St. Louis, MO 63130
314-935-5493
WWW Site: http://pds-geosciences.wustl.edu
Electronic mail address: geosci@wunder.wustl.edu

MOLA Science Team
Code 920
NASA / Goddard Space Flight Center
Greenbelt, MD 20771
WWW Site: http://ssed.gsfc.nasa.gov/tharsis/mola.html
Electronic mail address: Gregory.Neumann@GSFC.NASA.GOV

7. Cognizant Persons

MOLA data were provided by David Smith, MOLA Principal Investigator, with assistance from Greg Neumann, both of NASA/Goddard Space Flight Center, and Peter Ford, MIT.

This volume was designed and produced by Susan Slavney, Planetary Data System Geosciences Node, Washington University, St. Louis, Missouri.

8. Citations

The MOLA PEDR data set published on this volume may be cited in published literature using the following reference.

Smith, D., G. Neumann, P. Ford, R. E. Arvidson, E. A. Guinness, and S. Slavney, "Mars Global Surveyor Laser Altimeter Precision Experiment Data Record", NASA Planetary Data System, MGS-M-MOLA-3-PEDR-L1A-V1.0, 1999.