R. Arvidson, E. Guinness and S. Slavney
Department of Earth and Planetary Sciences
St. Louis, MO 63130
R. J. Springer
Jet Propulsion Laboratory
Pasadena, California 91109
July 3, 1997
Specific aspects addressed in this plan are:
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
R.E. Arvidson Washington Weathering and Chair, Data & Archives Working Group University M. Carr United States Geosciences Geological Survey A. Ingersoll California Polar atmospheric science Institute of Technology B. Jakosky University of Surface-atmospheric science Colorado R. Haberle Ames Research Climatology Center L. Soderblom United States Surface processes and geomorphology Geological Survey
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 Totals 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
Magnetometer/ Electron Time Series Data (MAG-TSD) Orbital Map (MAG-OM) Reflectometer Mars Orbital Camera Narrow Angle Standard Data Product (MOC-NA-SDP) Wide Angle Standard Data Product (MOC-WA-SDP) Global Map Image (MOC-GMI) 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)
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
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
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)
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
Software Interface Specification documents
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.
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) grouping SPAE017 Time Series Data TOV 1A 4 258.4 6,330.0 (MAG-TSD) 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 (MOC-NA-SDP) Wide Angle Standard GP 1A 4 1,179.6 28,900.0 Data Product (MOC-WA-SDP) SPAE023 Global Map Image GP 3 4 217.1 5,320.0 (MOC-GMI) 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 (MOLA-PEDR)** SPAE027 Initial Degree GP 3 4 1.8 44.0 Experiment Gridded Data Record (MOLA-IEGDR) Mission Experiment GP 3 98 311.0 311.0 Gridded Data Record (MOLA-MEGDR) SPAE034 Atmospheric TOV 3 4 242.0 5,928.0 Temperature-Pressure 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 (RS-DM-F)*** SPAE049 Line-Of-Sight TOV 2 4 45.5 1,114.0 Acceleration Profiles (RS-LOSAPDR) 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 (TES-GDSPM) Final Global Derived GP 3 98 50.0 50.0 Surface Property Map (TES-GDSPM-F) 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.
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 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.
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.
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.