Mars Global Surveyor Project
Archive Generation, Validation, and Transfer Plan

Prepared by:

R. Arvidson, E. Guinness and S. Slavney
Department of Earth and Planetary Sciences
Washington University
St. Louis, MO 63130

R. J. Springer
Jet Propulsion Laboratory
Pasadena, California 91109

Document # 542-312

July 3, 1997




      1.1 Purpose
      1.2 Scope
      1.3 Contents
      1.4 Applicable Documents and Constraints
      2.1 Mission Overview
      2.2 Ground Data System
      3.1 Generation
      3.2 Validation and Delivery
      4.1 Mars Global Surveyor
      4.2 Planetary Data System
      4.3 National Space Science Data Center
      5.1 Postings for Outreach and Education
      5.2 Archive Volumes for Science Community Use


1.1 Purpose

The purpose of this document is to provide a plan for generation, validation, and transfer to the Planetary Data System (PDS) of Mars Global Surveyor (MGS) archives containing raw and reduced data, documentation, and algorithms/software. A second purpose is to delineate plans for posting on the Internet a subset of derived data and documentation that shows interesting and timely results.

1.2 Scope

The plan covers archiving of raw and reduced data sets and related information to be acquired or derived during the MGS mission mapping phase, which is scheduled to begin in March 1998 and to end in January 2000. Data acquired before the mapping phase (e.g., during cruise, orbit insertion, and circularization) may be included in archives of mapping phase data. Data archive generation will continue after the mapping phase into the analysis phase of the mission, ending in September 2001. A plan for an extended relay mission for the Mars Surveyor Program will be prepared later as needed. Finally, addenda to this Plan will be published at a later date if products generated by MGS Interdisciplinary Scientists (e.g. global circulation model output) are deemed appropriate for archiving.

Specific aspects addressed in this plan are:

  1. Generation of high-level mission, spacecraft and instrument documentation, instrument calibration reports, algorithms, and documentation of software used to produce Levels 1 to 3 reduced data records.

  2. Reduction of science packet data (i.e., packetized level 0 data) to reduced data records, including generation of data sets expressed in geophysical units, with associated documentation that determines when and where the data were acquired and for what purpose.

  3. Generation of SPICE archives for use with software from the Jet Propulsion Laboratory's Navigation and Ancillary Information Facility (NAIF).

  4. Generation and validation of archive volumes containing MGS data, software, algorithms, documentation, and ancillary information.

  5. Delivery to the PDS of validated MGS archives.

1.3 Contents

This plan begins with a summary of MGS mission phases and an overview of the ground data system. This section is followed by a description of the roles and responsibilities for organizations and personnel associated with generation, validation, and archiving of MGS data. The document ends with specific plans for archiving and for posting of subsets of data for outreach and educational purposes. For reference, Appendix I is a glossary of selected terms used in this document.

1.4 Applicable Documents and Constraints

The MGS Archive Generation, Validation, and Transfer Plan is responsive to the following Mars Global Surveyor documents:

    Project Plan (Doc. 542-10, Dec. 1994).

    Mission Plan (Doc. 542-405, Jul. 1995).

    Investigation Description and Science Requirements Document (Doc. 542-300, Feb. 1995, JPL D-12487).

    Project Data Management Plan (Doc. 542-403).

    Science Data Management Plan (Doc. 542-310).

    Mission Operations (Doc. 542-409, vol. 1-12).

    The plan is consistent with the principles delineated in the following National Academy of Sciences reports:

    Data Management and Computation, Volume 1, Issues and Recommendations, 1982, National Academy Press, 167 p.

    Issues and Recommendations Associated with Distributed Computation and Data Management Systems for the Space Sciences, 1986, National Academy Press, 111 p.

    The plan is also consistent with the following Planetary Data System documents:

    Planetary Science Data Dictionary Document, July 15, 1996, JPL D-7116, Rev D.

    Planetary Data System Data Preparation Workbook, February 1, 1995, Version 3.1, JPL D-7669, Part-1.

    Planetary Data System Data Standards Reference, July 24, 1995, Version 3.2, JPL D-7669, Part-2.

    Finally, the plan is meant to be consistent with the contracts negotiated between the MGS Project and each Principal Investigator (PI), Team Leader (TL), and Interdisciplinary Scientist (IDS), in which reduced data records and documentation are explicitly defined as deliverable products.


2.1 Mission Overview

The MGS spacecraft will be placed into orbit about Mars in September 1997 and begin a 211-day phase that results in a mapping orbit (Figure 1). Mapping will begin in March 1998 and extend for a full Mars year (687 Earth days); i.e., until January 2000. The near-polar mapping orbit will have a 118-minute period with a 7-sol near-repeat groundtrack. Each 7-sol cycle will be systematically offset from the next by approximately 1 degree at the equator. The 7-sol mapping cycle is important for product generation in that this period covers one cycle of global observations. Thus, in this Plan gridded standard products will be defined, in part, on the basis of the integer number of mapping cycles worth of data incorporated into the products.

The MGS Mission has objectives that pertain to geosciences and atmospheric sciences. The primary geoscience objectives include the global definition of the topography and the gravitational field, global determination of the mineralogical character of surface materials, and determination of the nature of the magnetic field around Mars. The primary climatology objectives are the determination of the time and space distribution, abundances, sources and sinks of volatile material and dust over a seasonal cycle, as well as the delineation of atmospheric structure and dynamics. MGS objectives require mapping and result in raw and derived data sets that have both spatial and temporal dimensions. The intent is to generate a suite of products that depict atmospheric, surface, and subsurface characteristics as a function of latitude, longitude, altitude (as appropriate), and time.

Table 1 shows instruments on MGS, measurements to be made, and investigators responsible for the instruments. Table 2 lists the Interdisciplinary Scientists and their planned activities. For reference, Table 3 is a summary of raw data to be acquired by each instrument over the course of the nominal MGS Mission.

Through extensive discussions within the Mars Observer (MO) Data and Archives Working Group, a set of standard products were compiled for each MO experiment. The majority of those products are to be generated for MGS. The list is shown in Table 4 and descriptions are given in Appendix II. The products consist of documentation/ancillary data, time sorted vectors (e.g., TES along track spectral radiances), and gridded products (e.g., digital elevation maps from MOLA).

A fundamental tenet of the Mars Surveyor Program and MGS is that each PI and TL is obligated to deliver to the PDS a complete, validated archive of his data by the end of mission, September 30, 2001.

2.2 Ground Data System

The MGS ground data system will involve a centralized mission operations component at JPL and a distributed component located at home institutions of the Principal Investigators, the Radio Science Team Leader, Interdisciplinary Scientists, Team Members, Co-Investigators, and Participating Scientists. Science Operations Planning Computer (SOPC) workstations located at Principal Investigator, Team Leader, and Interdisciplinary Scientist home institutions will be electronically connected via NASCOM links to a Project Data Base at JPL. Personnel at JPL and those with SOPC workstations will use the Project Data Base to coordinate observation planning. Level 0 science data in packetized form, SPICE files, and relevant engineering data will be placed in the PDB for access by Principal Investigators and the Radio Science Team Leader. These files will be transferred to the relevant home institutions for examination and generation of reduced data records.

Each Principal Investigator and the Radio Science Team Leader is responsible for getting the products to his respective team members and to interdisciplinary scientists and participating scientists, under the guidelines of data use outlined in the MGS Science Data Management Plan. It is expected that ftp transfers, use of CD-WOs, and other transfer mechanisms will be used to get data to the relevant individuals. This science part of the ground data system will be based on existing systems and/or purchases for science use and will not formally be part of the MGS ground data system. Finally, each Principal Investigator and the Radio Science Team Leader will maintain an on line data base, accessible over Internet, that contains recent reduced data of general interest, together with documentation explaining the products and their relevance to MGS and Mars science. These postings are to be generally available to Internet users for outreach and educational purposes.


Standard products form the core of the archives to be produced by MGS and released to the PDS for distribution to the science community. These products and associated raw data, SPICE files, and ancillary information will be placed on archive volumes for validation and transfer to the PDS. A logical grouping of volumes is termed an archive collection (Appendix I). Table 5 lists the key elements associated with archive collections and Table 6 lists suppliers of data and information for MGS archive collections. There will be one archive collection (and associated volumes) for each instrument, one for SPICE files, one for level 0 science packets for MOC, MOLA, TES, and MAG/ER, together with engineering data, and one for level 0 radio science data, for a total of 8 archive collections (and associated volumes).

In the following section we discuss the processes and schedules for generation and validation of standard products and archive volumes and ingestion by the PDS. Figure 2 shows the flow of components through the various stages of archive volume generation, validation, transfer to the Planetary Data System, and distribution of products to the science community. Also shown is posting of timely results on Internet for education and outreach.

3.1 Generation

Generation of archive volumes of level 0 spacecraft instrument science packets, spacecraft engineering packets, DSN monitor packets, and SPICE files is the responsibility of Data Administration. Generation of archive volumes of raw radio science data is the responsibility of the Radio Science Team

The Science Operations Team will be responsible for the generation of reduced data records (as standard data products), documentation, algorithms or software to generate levels 1 to 3 products. Archive volumes will be assembled under Principal Investigator and Radio Science Team Leader auspices.

3.2 Validation and Delivery

Validation of level 0 science packets and SPICE files will be an intrinsic part of standard product generation. Validation of standard products will be done in part during analysis of the data. However, a key additional requirement is the validation of archive volumes for integrity of scientific content, file structures (e.g., do the files conform to Software Interface Specification documents?), directory structures, compliance with PDS standards, and integrity of the physical media used to transfer the data set collections. This validation will be overseen by the Science Operations Team through its Science Data Validation Team.

The Science Data Validation Team will consist of a Team Chief, the Interdisciplinary Scientist for Data and Archives, Experiment Representatives, PDS Mission Interface Team Representative, the Multimission Ground Data System Data Base Administrator, and a representative from each Science Team. These personnel will work with the Principal Investigators and the Radio Science Team Leader, examining volumes and generating reports that delineate problems.

The Science Operations Team will have veto power on whether given archive volumes are ready for transfer to the PDS. Errors, if minor, may simply be documented. Large errors would require corrections and regeneration of the respective volumes. If given volumes pass validation, then the Principal Investigator or Radio Science Team Leader would transfer the archives to the PDS, based on the release schedule given in Section 5 of this Plan.

Final validation will take place under PDS auspices as a check of archive volumes before release to the planetary community. Problems due to obvious errors in science, missing files, and inadequate documentation will be referred back to the MGS Project for correction, although it is expected that such referrals will be highly unusual because of the work of the Science Teams and the Science Data Validation Team. A fundamental aspect of the release schedule is that level 0 science packets, SPICE files, and algorithms/software generating levels 1 to 3 data products are released at the same time as reduced data records generated from the relevant science packet data.


In this section the roles and responsibilities for personnel and organizations involved in MGS archive generation, validation, transfer, and distribution are summarized.

4.1 Mars Global Surveyor

The Project Scientist and the Project Science Group (Project Scientist, Team Leaders, Principal Investigators, and Interdisciplinary Scientists) provide an oversight function for implementation of the Archive Generation, Validation, and Transfer Plan. The MGS Interdisciplinary Scientist for Data and Archives, with input from the SDVT and the MGS Project Science Group, will advise the Project with regard to archiving and will work with MGS and the PDS to help ensure that detailed plans are in place for generation of Planetary Data System-compatible products and associated documentation, and that archive volumes are generated, validated, and transferred to the Planetary Data System.

MGS Data Administration will compile archive volumes containing engineering, level 0 science packets from spacecraft instruments, DSN monitor data, and SPICE files. The Radio Science Team Leader will produce the Radio Science level 0 archive collection. Principal Investigators are responsible for generation of reduced science data records, documentation, algorithms/software to generate levels 1 to 3 products, and archive volumes containing standard products and supporting information. The Radio Science Team Leader will not supply reduction software, but will instead provide documentation to explain how the processing is carried out. Table 6 lists the suppliers for each component of the archive collections. The author of each archive collection (and associated volumes) is responsible for publishing a Software Interface Specification document that delineates the format and content of the respective volumes. These SISs are due in final form by the time of orbit insertion. Generally, the relevant SIS is included on the archive volume.

Each Principal Investigator and the Radio Science Team Leader will also be responsible for posting a subset of reduced data (and relevant documentation) on a system accessible via the Internet for public access.

As discussed in Section 3.2, the Science Data Validation Team (SDVT) will be responsible for reviewing the initial archive volumes. Note that the Data and Archives Working Group (DARWG) discussed in the MGS Science Data Management Plan has been replaced by the SDVT.

The MGS Project will provide funds for production (e.g., premastering of CD-ROMs) and distribution of archive volumes for use by the MGS community.

4.2 Planetary Data System

The PDS is the designated point of contact for MGS on archive-related issues. The interfaces between the MGS teams and elements of the Planetary Data System are summarized in Table 7. The PDS is also the interface between MGS and the NSSDC.

The PDS, through its Mission Interface Team and with help from its Discipline Nodes, will work with the SDVT and other MGS elements to ensure that the MGS archives are compatible with PDS standards and formats. The PDS will provide funds for generation, distribution, and maintenance of MGS archives volumes for the NASA-supported science community after the volumes have been released by MGS.

4.3 National Space Science Data Center

The National Space Science Data Center will maintain a "deep archive" of MGS data for long-term preservation and for filling large delivery orders to the science community. The PDS will deliver copies of MGS archive volumes to NSSDC.


5.1 Postings for Outreach and Education

It is expected that each Principal Investigator and the Radio Science Team Leader will develop a World-Wide Web site for his instrument or experiment. This site will be operational by the time of launch and will have pointers to the MGS Project Web site and to the other MGS instrument/experiment sites. Within a month after start of mapping operations, each of the instrument/experiment Web sites will provide access to reduced data and documentation that illustrate exciting results from the observations. Updates to the postings of reduced data and documentation will be done at least for every mapping cycle, or 7 sols.

For MOC, a large subset of images will be posted. For TES, selected spectra will be displayed, along with maps depicting derived parameters such as composition of the surface. MOLA postings will include along track elevation data and maps depicting surface elevations. MAG/ER postings will be similar in form to those for MOLA. The Radio Science postings will include atmospheric temperature, pressure profiles and gravity vector and map-oriented presentations.

5.2 Archive Volumes for Science Community Use

As discussed above, standard products will be generated in systematic manners during the course of the mission. These products will be used for analyses and some will be posted for education and outreach. A final and important purpose for the standard products is to provide the research community with the best derived data for their analysis. Table 8 lists the standard products, the number of cycles worth of data to be included in the products, the number of times the products will be issued, and data volumes. Also included are the processing levels for each product, using level definitions provided in Appendix III.

The standard products are the core data sets for archive volumes to be delivered to the PDS. Further, all raw data and SPICE files used to generate the standard products will be released to the PDS at the same time that the standard products are released.

In the MGS Science Data Management Plan it is assumed that standard products (and associated raw data and SPICE files) will be delivered to the PDS six months after receipt of the last raw data used in generating the standard products. However, a 20-month science analysis phase is now planned to follow the end of the mapping phase. Generation of archive volumes will extend throughout the analysis phase. This means that for most products, the period of time between acquisition and delivery to the PDS will be over six months. This plan is consistent with reduced funding relative to earlier incarnations of budgets and archive plans for MGS.

The first delivery of archives to the PDS will take place six months after start of mapping, September 1998, and will contain data from the first four mapping cycles (28 sols). This will be followed by a delivery every six months, with each delivery containing up to 16 mapping cycles worth of data. The last data acquired at the end of the mapping phase (January 2000) will be delivered at the end of the analysis phase (September 2001). Using this schedule and the data given in Table 8, it is possible to generate size estimates for delivery of archive volumes to the PDS (Table 9).

During the period between receipt of data and delivery of archive volumes to the PDS, standard products will be generated and validated, archive volumes will be assembled and placed on relevant media (e.g., CDs), and the volumes will be validated.

Figure 1. Timeline showing MGS mission activities and archive volume deliveries to the PDS. The first delivery would be six months after start of mapping and would consist of data from the first four mapping cycles. Deliveries would then take place every six months and consist of data from subsequent mapping cycles. Also shown are the timelines for World-Wide Web home pages and SIS publications. Note that the delivery of data from cycles 69 through 84 is not shown in the figure due to space limitations.

Figure 2. Flow of MGS archive volume generation, validation, and transfer. Also shown is posting of reduced data for outreach and education.

TABLE 1. Mars Global Surveyor Instruments

NASA MAG/ER           Up to 16 magnetic field vectors per second.    Mario Acuña,        
(Magnetometer/        Electron reflectometer will determine          Goddard Space       
Electron              electron pitch angle distribution, field       Flight Center       
Reflectometer)        strength, altitude dependence of field.                            
                      Continuous operation.                                              

MOC (Mars Orbital     Wide angle imaging able to generate global     Michael Malin,      
Camera)               map in one Sol with 7.5 km/pixel resolution.   Malin Space         
                      Wide angle for regional imaging with 250       Science Systems,    
                      m/pixel resolution at nadir. Global imaging    Inc.                
                      using blue or red filters. Narrow angle (NA)                       
                      cross track widths with 1.4 m/pixel. NA                            
                      images are accompanied by simultaneously                           
                      acquired WA context images.                                        

MOLA (Mars Orbital    Distances from spacecraft to nadir surface     David Smith,        
Laser Altimeter)      locations with vertical resolution of          Goddard Space       
                      several meters. Surface reflectivity at 1.06   Flight Center       
                      micrometer from backscattered power.                               
                      Operates continuously at 10 pulses/second.                         

TES (Thermal          Emitted radiance from 6.25 to 50 micrometer    Philip R.           
Emission              from surface and atmosphere with 10 cm- 1      Christensen,        
Spectrometer)         (apodized) resolution; Solar radiance from     Arizona State       
                      0.3 to 3.9 micrometers; Broadband radiance     University          
                      from 0.3 to 100 micrometers. Three kilometer                       
                      field of view at nadir. Nadir observations;                        
                      fore and aft surface observations to vary                          
                      emission angle; limb observations.                                 

RS (Radio Science)    Radio occultation measurements of polar        G. Leonard Tyler,   
                      atmosphere to obtain profiles of refractive    Team Leader,        
                      index, number density, temperature, and        Stanford            
                      pressure for lowest several scale heights.     University          
                      Atmospheric scintillation measurements will                        
                      also be obtained. Radio tracking of                                
                      spacecraft for information on gravitational                        
                      field. Orbital decay due to air drag by                            
                      analysis of spacecraft orbital evolution.                          

TABLE 2. Interdisciplinary Scientists

R.E. Arvidson  Washington       Weathering and Chair, Data & Archives Working Group      

M. Carr  United States          Geosciences                                              
Geological Survey                                                                        

A. Ingersoll  California        Polar atmospheric science                                
Institute of Technology                                                                  

B. Jakosky  University of       Surface-atmospheric science                              

R. Haberle  Ames Research       Climatology                                              

L. Soderblom  United States     Surface processes and geomorphology                      
Geological Survey                                                              

TABLE 3. Instrument Data Rates and Volumes

Data Returned (S&E 1) in Gbits

MAG/ER                         50.6                                   
MOLA                           36.7                                   
TES                            70.9                                   
MOC                            315.1                                  
Data Returned (S&E 2) in Gbits

TES                            25.1                                   
MOC                            147.3                                  
Radio Science Data in Gbits

Occultations                   170                                    
Tracking                       150                                    

MAG/ER                          50.6                                   
MOLA                            36.7                                   
TES                             96.0                                   
MOC                            462.4                                  
RS                             464                                    
Total                         2075.4 or approximately 259.4 Gbytes   

Notes: 	Sum equivalent to approximately 400 CD-ROMs
	RS data estimate from Richard Simpson, Stanford University
	Other data from MGS Project 9/19/95

TABLE 4. Standard Data Products by Instrument

Magnetometer/ Electron     Time Series Data (MAG-TSD) Orbital Map (MAG-OM)               

Mars Orbital Camera        Narrow Angle Standard Data Product (MOC-NA-SDP) Wide Angle    
                           Standard Data Product (MOC-WA-SDP) Global Map Image           

Mars Orbital Laser         Aggregated Experiment Data Record (MOLA-AEDR) Precision       
Altimeter                  Experiment Data Record (MOLA-PEDR) Initial Experiment         
                           Gridded Data Record (MOLA-IEGDR) Mission Experiment Gridded   
                           Data Record (MOLA-MEGDR)                                      

Radio Science              Occultation Summary File (RS-OCCSUM) Atmospheric              
                           Temperature-Pressure Profiles  (RS-TP) Intensity Power        
                           Spectra From Atmospheric Scintillations (RS-IPS)              
                           Line-of-sight Acceleration Profiles (RS-LOSAPDR) Spherical    
                           Harmonic Models of Gravity Field (RS-SH) Radio Science        
                           Digital Maps (RS-DM)                                          

Thermal Emission           Observational Parameters (TES-OBS) Global Derived Surface     
Spectrometer               Property Maps (TES-GDSPM)                                     

TABLE 5. Components of Mars Global Surveyor Archive Collections

SPICE Archive Collections
	SPICE Kernel Software Interface Specification Documents
	SPICE Kernels
	NAIF Software

Science Data Archive Collections High-level catalog mission, spacecraft, instrument, and data set collections, data set templates Software Interface Specification Documents Processing Descriptions, Algorithms, and Software (to use in understanding reduced data record generation) Instrument Calibration Reports and associated data needed to understand level 1 product generation Standard Data Products Labels Data Objects

Engineering and Level 0 Science Data Archive Collections

Archive Collection and Volume Software Interface Specification Document Data Product Software Interface Specification Documents Science Packet Data Products Labels Data Objects Engineering Data Products Labels Data Objects

Radio Science Level 0 Data Archive Collection

High-level catalog files Archive Collection and Volume Software Interface Specification Document Data Product Software Interface Specification Documents (as available) Original Data Stream Files Labels Data Objects Archival Tracking Data Files Labels Data Objects Orbit Data Files Labels Data Objects Ancillary Files

TABLE 6. Mars Global Surveyor Archive Collection Component Suppliers

Science Operations Team (SOT)

Planetary Data System high-level catalog templates I Kernels E Kernel contributions---instrument specific Reduced Data Records Standard Data Products Special Data Products Detailed-level catalog information in label keywords Processing algorithms and software to go from level 0 to level 1 products Instrument calibration reports and associated data

Data Administration

E Kernels Science packet data Engineering packet data Monitor data [RTOT(DSO)] SPICE file archive Engineering data archive files

Spacecraft Team (SCT)

C Kernels Spacecraft Status Report Mission Controllers Real-Time Operations Log

Navigation Team (NAV)

SP Kernels

Mission Planning and Sequencing Team (PST)

Predicted Events File as input to the E Kernel Sequence of Events File as input to the E Kernel

Radio Science [SOT(RS)]

Radio Science Files

All Teams

Software Interface Specification documents

TABLE 7. Planetary Data System Responsibilities for Archiving Mars Global Surveyor Data

Planetary Data System Organization     Responsibility

Central Node/Mission Interface Team    Overall coordination with Mars Global Surveyor   
                                       Project, including joint planning efforts.       

Geosciences Node                       Archive TES, MOLA, and RS gravity volumes.       

Atmospheres Node                       Archive RS occultation volumes, TES              
                                       atmospheric volumes.                             

Image Node                             Archive MOC volumes.                             

NAIF Node                              Archive SPICE Kernels; NAIF Toolkit; level 0     
                                       science instrument data packets and              
                                       engineering data, including DSN monitor data;    
                                       and Radio Science level 0 archive collection.    

Plasma Interactions Node               Archive MAG/ER volumes.                          

TABLE 8. Standard Data Product Types and Sizes

MGS I/F   Description and Acronym  Data      Data     Number of   Size of     Data set    
   ID                              Type*     Level    7-sol       product     size        
                                                      cycles in   grouping    (Mbytes)    
                                                      product     (Mbytes)                

SPAE017   Time Series Data           TOV     1A       4                258.4  6,330.0     

SPAE018   Orbital Map (MAG-OM-P)      GP     3        49                 2.0  2.0         
          Orbital Map (MAG-OM-F)      GP     3        98                 2.0  2.0         

SPAE020   Narrow Angle Standard       GP     1A       4              1,179.6  28,900.0    
          Data Product                                                                    
          Wide Angle Standard         GP     1A       4              1,179.6  28,900.0    
          Data Product                                                                    

SPAE023   Global Map Image            GP     3        4                217.1  5,320.0     

SPAE067   Aggregated Experiment      TOV     1B       4                218.7  5,359.0     
          Data Record (MOLA-AEDR)                                                         

SPAE026   Precision Experiment       TOV     1B       4                962.0  23,570.0    
          Data Record                                                                     

SPAE027   Initial Degree              GP     3        4                  1.8  44.0        
          Experiment Gridded                                                              
          Data Record                                                                     
          Mission Experiment          GP     3        98               311.0  311.0       
          Gridded Data Record                                                             

SPAE034   Atmospheric                TOV     3        4                242.0  5,928.0     
          Profiles (RS-TP)                                                                

SPAE070   Occultation Summary        TOV     N/A      4                  0.6  14.0        
          File (RS-OCCSUM)                                                                

SPAE038   Intensity Power            TOV     N/A      4                109.1  2,674.0     
          Spectra (RS-IPS)                                                                

SPAE041   Radio Science Gravity       GP     3        49                90.0  90.0        
          Models, Spherical                                                               
          Harmonic Models (RS-SH)                                                         
          Final Radio Science         GP     3        98                90.0  90.0        
          Gravity Models,                                                                 
          Spherical Harmonic                                                              
          Models (RS-SH-F)                                                                

SPAE044   Radio Science Digital       GP     3        49                 6.0  6.0         
          Maps (RS-DM)***                                                             
          Final Radio Science         GP     3        98                 6.0  6.0         
          Digital Maps                                                                    

SPAE049   Line-Of-Sight              TOV     2        4                 45.5  1,114.0     
          Acceleration Profiles                                                           

SPAE052   TES Observational          TOV     1A       4              4,700.5  115,162.0   
          Parameters (TES-OBS)                                                            

SPAE055   Global Derived Surface      GP     3        12                 4.0  4.0         
          Property Map                                                                    
          Final Global Derived        GP     3        98                50.0  50.0        
          Surface Property Map                                                            
          Total                                                               247,869.0   

*   TOV:  Time Ordered Vector; GP: Gridded Product; DAI: Documentation,
	  Ancillary Information

** Multiple versions will be produced; the final version will be in the permanent archive.

*** Some Radio Science map products will have fewer cycles than shown in a product grouping.

Note: Level descriptions can be found in Appendix III.

TABLE 9. Summary of Archive Sizes (in Mbytes) For Each Delivery to the PDS

  PDS   Delivery  Mapping    MAG/ER     MOC      MOLA      RS        TES      Total per   
Delivery  Date    Cycles                                                      Delivery

   1     Sep-98     1-4        258.4   2,576.3  2,154.6   397.2     4,700.5    10,087.0

   2     Mar-99    5-20      1,033.6  10,305.2  8,639.8   1,588.8   18,806.0   40,373.4

   3     Sep-99   21-36      1,033.6  10,305.2  8,661.2   1,588.8   18,802.0   40,390.8

   4     Mar-00   37-52      1,035.6  10,305.2  8,639.8   1,684.8   18,802.0   40,467.4

   5     Sep-00   53-68      1,033.6  10,305.2  8,639.8   1,588.8   18,802.0   40,369.4

   6     Mar-01   69-84      1,033.6  10,305.2  8,661.2   1,588.8   18,802.0   40,390.8

   7     Sep-01   85-98        906.4   9,017.1  7,873.5   1,486.2   16,501.8   35,785.0

                  Total      6,334.8  63,119.4  53,269.9  9,923.4  115,216.3  247,863.8


Archive collection -- A group of related data sets, supplemental data, software, and documentation that are logically linked to facilitate their use and administration. An example of an archive collection is the MGS MOLA Science Data Archive Collection.

Archive volume, archive volume set-- A volume is a single unit of media on which one or more data sets are stored; e.g., one CD-ROM. When the data span multiple volumes, the group of volumes is called a volume set. The media supported by PDS are CD-ROMs and magnetic tape. Within each volume is a directory structure listing the subdirectories and files contained on that volume. Magnetic tapes have a "virtual" directory structure provided in a directory and file map included on the volume.

Data product, standard data product -- A data product is a labeled grouping of data resulting from a scientific observation, usually stored in a single file. A product label identifies, describes, and defines the structure of the data. A standard data product is a reduced data record generated in a standard or predefined way using well-understood procedures, processed in "pipeline" fashion. Examples of a standard data product are a MOC narrow angle image, a Radio Science intensity power spectrum, and a MAG time series table. Data products that are generated in a nonstandard way are sometimes called special data products.

Data set- A logical grouping of data products; e.g., the set of all MOC narrow angle images, all RS power spectra, or all MAG time series tables.

High-level catalog -- High-level descriptive information about mission, spacecraft, instrument, data sets, and related items. Catalog inputs derived from templates expressed in Object Description Language (ODL) which are suitable for loading into a catalog.

Reduced data record -- A data product generated by processing raw science data to some level (see Appendix III for definitions of processing levels).

Science packets -- Level 0 (raw) data for a given instrument in packetized form.


Below are brief descriptions of each of the MGS Standard Data Products. Each Standard Data Product is identified first by a MGS interface ID and is followed by a product acronym.


Vector magnetic field as a function of time along spacecraft orbit.


Orbital altitude map of average magnetic field (components and magnitude). Plans include initial and final versions.


Wide-angle image data of the following types of observations: regional mapping; limb observation; global mapping; or narrow angle context image.


Narrow-angle image data containing high-resolution sampling or targeted narrow angle image.


Global map images. Plans include initial and final versions.


The MOLA Experiment Data Records (EDR) including both science and maintenance mode data packets aggregated by Mars Global Surveyor orbit.


Time series, along track MOLA data science mode data in geophysical units. A record contains range, orbit data (time, latitude, longitude, areocentric distance), elevation, relative pulse energy, and match filter number. Includes engineering and housekeeping data.


Initial MOLA corrected profile data mapped to a 5x5-degree grid. The cells shall contain elevation, height variance, and relative reflectivity. Also, a data density per grid cell shall be given.


MOLA corrected profile data for the entire mission, mapped to a 0.25 x 0.25-degree grid. The cells shall contain elevation, height variance, and relative reflectivity. Also, a data density per grid cell shall be given.


Occultation summary file covering approximately one-month periods of observations. Will include observing conditions, temperature, pressure, occultation radius, column content, and pointer back to T-p profile files, i.e., to RS-TP files.


(a) Atmospheric temperature and pressure vs. altitude near each occultation point at approximately 200 m vertical resolution over 0-100 km.

(b) Atmospheric temperature and pressure vs. altitude near each occultation point at approximately 10-20 m vertical resolution over 0-100 km.


Intensity power spectra from spectral analysis of atmospheric scintillations in radio occultation data.


Line of sight acceleration profiles, giving the component of spacecraft acceleration along Earth-Mars line as a function of spacecraft position in its orbit.


Spherical harmonic expansions of gravity field:

(a) ASCII files containing coefficients

(b) Binary file equivalents, with covariance terms


Maps showing Bouguer, isostatic, and free air anomalies


Raw, calibrated and atmosphere corrected radiance observations produced by the TES instrument, stored in time series format. Includes up to 143 spectrometer channels, plus 1 solar albedo channel and 1 thermal bolometric channel for each IFOV. Also included for each observation are the instrument state parameters and observing geometry. Where it is possible to derive them, the following surface and atmospheric properties are also included: surface radiance, surface temperature, surface pressure, thermal inertia, atmospheric opacity, single scattering albedo, dust column density and pressure-temperature profile.


TES derived surface properties maps, including principal component unit maps, surface composition based on Project-agreed algorithm, thermal inertia, albedo, rock abundance, and surface frost occurrence. Plans include initial and final versions.


LEVEL 0 -- Instrument science packets (e.g., raw voltages, counts) at full resolution, time ordered, with duplicates and transmission errors removed. Corresponds to Space Science Board's Committee on Data Management and Computation (CODMAC) Edited Data (see National Academy press, 1986).

NOTE: Following levels correspond to Reduced Data Records and may correspond to Standard or Special Data Products.

LEVEL 1A -- Level 0 data which 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). Corresponds to CODMAC Calibrated Data.

LEVEL 1B -- Irreversibly transformed (e.g., resampled, remapped, calibrated) values of the instrument measurements (e.g., radiances, magnetic field strength). Corresponds to CODMAC Resampled Data.

LEVEL 1C -- Level 1A or 1B data, which 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). Corresponds to CODMAC Derived Data.

LEVEL 2 -- Geophysical parameters, generally derived from Level 1 data, and located in space and time commensurate with instrument location, pointing, and sampling. Corresponds to CODMAC Derived Data.

LEVEL 3 -- Geophysical parameters mapped onto uniform space-time grids. Corresponds to CODMAC Derived Data.