PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT INTERCHANGE_FORMAT = ASCII PUBLICATION_DATE = 2009-02-06 NOTE = "N/A" END_OBJECT = TEXT END Mars Global Surveyor Radio Science Team Electron Density Profile Archive (MGS-M-RSS-5-EDS-V1.0) AAREADME.TXT R.A. Simpson Stanford University ============================================================================== OVERVIEW ============================================================================== This archival volume contains the entire collection of radio occultation ionospheric electron density (EDS) profiles derived from Mars Global Surveyor (MGS) data during the MGS mission. The profiles were archived previously as part of the MGS-M-RSS-5-SDP-V1.0 data set, which is contained in a different archive volume. These are the same profiles, but they have been collected into a single volume where they are organized chronologically. The accompanying PDS detached labels are also the same except for minor edits needed for conformance to the new data set. ============================================================================== VOLUME STRUCTURE ============================================================================== The volume has four files and four directories at the root level. The AAREADME.TXT file (this file) provides an overview of the archive; the ERRATA.TXT file contains notes, warnings, and known errors in the data set at the time the volume was produced; and the VOLDESC.CAT file contains catalog information. The DATA directory contains two sub-directories: EDS directory contains electron density files arranged into subdirectories by year and month. The OCS directory contains a single file which is a summary table of all 5600 electron density profiles (the slightly edited header record from each EDS file). Each entry in the table gives the latitude and longitude of the occultation point, the solar longitude (Ls) of Mars, the solar zenith angle, the local true solar time, names of files used in the processing, and the name of the parent EDS file. In the INDEX directory the INDEX.TAB file contains a listing of the data files in the volume, together with some properties of those files. The CATALOG directory contains descriptive information. Included are files describing the mission, instrument, and data set. The DOCUMENT directory contains more specific information on the file organization and structure. Included is a Software Interface Specification (SIS) document, describing the organization of the volume and and its files. Also included is the OCCLOG.TAB file, which is a summary of each observation opportunity with equipment settings from data acquisition and results from early processing. This table has 33888 rows, including summaries of tests and failed observation attempts. The diagram below shows the organization of this volume, starting from the root of the compact disc. root | |- AAREADME.TXT |- ERRATA.TXT |- VOLDESC.CAT |- CHECKSUMS.TXT | |- CATALOG | | | |- CATINFO.TXT Streamlined PDS catalog files | |- MGS_MISSION.CAT for mission, host, instrument, | |- MGS_INST_HOST.CAT references, personnel, data | |- MGS_RSS_INST.CAT set, and target. | |- MGS_RSS_REF.CAT | |- MGS_RSS_PERSON.CAT | |- MGS_RSS_5_EDS_DS.CAT | |- MGS_TARGET.CAT | |- DOCUMENT | | | |- DOCINFO.TXT Overview of directory | |- OCCLOG.TAB Summary of observation attempts | |- OCCLOG.LBL PDS label for OCCLOG.TAB | `- EDS_VOLM.TXT SIS for the volume | |- INDEX | | | |- INDXINFO.TXT Overview of directory | |- INDEX.LBL Label to INDEX.TAB | `- INDEX.TAB Table of contents for this volume | | | DATA DIRECTORIES | |- OCS Occultation Summary File | | | |- 812506AA.OCS Summary of EDS files | `- 812506AA.LBL PDS label for above | `- EDS Electron Density Profiles | | Directory containing EDS files organized into ... subdirectories by year and month. Typical file names are: ydddHmmN.EDS Nth solution for data beginning year y (last digit of year), day ddd, hour H, minute mm ydddHmmN.LBL PDS detached label for the above file To locate specific data files within the volume, users may consult INDEX.TAB in the INDEX directory. To search for occultations captured under certain conditions (solar zenith angle, latitude, season, etc.) users should sort the 812506AA.OCS file in the OCS directory. To find occultations meeting certain signal-to-noise ratio or observing criteria, sorting the OCCLOG.TAB files in the DOCUMENT directory may be the most appropriate strategy. ============================================================================== ERRATA ============================================================================== A cumulative list of notes, warnings, and known errors is maintained in the ERRATA.TXT file at the root level of each volume. ERRATA.TXT in the initial release of this volume will have little content, however. ============================================================================== FILE FORMAT ============================================================================== All data files on the disc are accompanied by detached PDS labels, which describe their contents. PDS TEXT objects have attached labels. Detached labels have the same file name as the data file except that the label name has the suffix "LBL". The label fully describes the format and content of its associated file. Detached labels use pointers to reference the data file -- for example, ^IMAGE = "JGM50C01.IMG" points to JGM50C01.IMG, which contains the actual image described by the label. Some data files contain more than one structure. For example, ^RSED_HDR_TABLE = ("8358D47A.EDS",1) ^RSED_TABLE = ("8358D47A.EDS",6) are pointers to the file 8358D47A.EDS which contains two tables, one beginning at record 1 and one beginning at record 6. Additional documentation on all data file types is available in the Volume Software Interface Specification in the DOCUMENT directory. Text files, including data files of ASCII text and all labels (*.LBL files) and tables (*.TAB files), are delimited with carriage-return (ASCII 13) line-feed (ASCII 10) pairs at the end of each line. In a departure from the practice in the original MGS-M-RSS-5-SDP-V1.0 archive, detached labels generally do NOT have fixed length records (of 80 bytes). This change was instituted to reduce the total volume of the EDS directory. Text and catalog files (*.TXT and *.CAT, respectively) do have fixed length records of 72 or 80 bytes, ending with a carriage-return line-feed pair. ============================================================================== CITATIONS ============================================================================== Users wishing to cite products in this volume should use the following volume information: Author: D.P. Hinson Editor: R.A. Simpson Volume Name: Mars Global Surveyor Radio Occultation Profiles of the Ionosphere - Reorganized Volume: USA_NASA_JPL_MORS_1102 Data Set ID: MGS-M-RSS-5-EDS-V1.0 Publisher: NASA Planetary Data System Year: 2008 ============================================================================== ACKNOWLEDGMENTS ============================================================================== These data were collected under auspices of the Mars Global Surveyor Project. G. Leonard Tyler of Stanford University was the Radio Science Team Leader. Members of the Team and its support elements involved in data acquisition and validation included Patricia Priest, Sami Asmar, Aseel Anabtawi, Elias Barbinis, Paula Eshe, Danny Kahan, Alex Konopliv, Frank Lemoine, William Sjogren, Tim Smith, and Joe Twicken. At PDS the assistance of Ed Guinness, Lyle Huber, Betty Sword, and Joel Wilf was appreciated. The data archive was reorganized into its present form at PDS PPI. ============================================================================== DISCLAIMER ============================================================================== Although considerable care has gone into making this volume set, errors are possible. Reports of errors or difficulties would be appreciated. Please contact one of the persons listed below. ============================================================================== COGNIZANT PERSONNEL ============================================================================== David Hinson was the lead scientist for radio occultation studies on the MGS Radio Science Team and was primarily responsible for extracting the electron density profiles from the raw data; he also reorganized the data for this volume. Dick Simpson, MGS Radio Science Team Experiment Engineer, assembled the volume. G. Leonard Tyler was the Leader of the MGS Radio Science Team. The present form of the archive was produced from the original CD-WO archive at the PPI Node of the PDS. David P. Hinson Center for Radar Astronomy Packard Building - Room 333 350 Serra Mall Stanford University Stanford, CA 94305 Tel: 650-723-3534 FAX: 650-723-9251 dhinson@stanford.edu or David P. Hinson SETI Institute 515 North Whisman Rd Mountain View, CA 94043 Tel: 650-810-0217 dhinson@seti.org Richard A. Simpson Center for Radar Astronomy Packard Building - Room 332 350 Serra Mall Stanford University Stanford, CA 94305 Tel: 650-723-3525 FAX: 650-723-9251 rsimpson@magellan.stanford.edu G. Leonard Tyler Center for Radar Astronomy Packard Building - Room 331 350 Serra Mall Stanford University Stanford, CA 94305 Tel: 650-723-3535 FAX: 650-723-9251 len.tyler@stanford.edu PPI Node of the PDS: PDS Operator c/o Dr. Raymond Walker 3845 Slichter Hall UCLA - IGPP Los Angeles, CA 90095-1567 Tel: (310) 206-6073 pds_operator@igpp.ucla.edu ============================================================================== ACRONYMS AND ABBREVIATIONS ============================================================================== CD Compact Disc HGA High-Gain Antenna MGS Mars Global Surveyor OCS Occultation Summary File (standard resolution products) PDS Planetary Data System RSS Radio Science Subsystem RST Radio Science Team SDP Science Data Products SIS Software Interface Specification T-p Temperature-pressure TPS Temperature-Pressure Profile (standard resolution) WO Write Once