PDS_VERSION_ID = PDS3 LABEL_REVISION_NOTE = "2002-12-13, GRS Team; 2002-09-30, GRS Team; 2003-12-17, GRS Team; 2004-03-23, GRS Team; 2004-11-19, GRS Team; 2005-06-24, GRS Team; 2005-08-31, GRS Team; 2005-11-30, GRS Team; 2006-09-06, GRS Team" OBJECT = DATA_SET DATA_SET_ID = "ODY-M-GRS-2-EDR-V1.0" OBJECT = DATA_SET_MISSION MISSION_NAME = "2001 MARS ODYSSEY" END_OBJECT = DATA_SET_MISSION OBJECT = DATA_SET_INFORMATION DATA_SET_NAME = "ODY MARS GAMMA RAY SPECTROMETER 2 EDR V1.0" DATA_SET_COLLECTION_MEMBER_FLG = "N" DATA_OBJECT_TYPE = TIME_SERIES START_TIME = 2001-04-25T23:00:32.834Z STOP_TIME = 'UNK' DATA_SET_RELEASE_DATE = 2002-10-03 PRODUCER_FULL_NAME = "WILLIAM BOYNTON" DETAILED_CATALOG_FLAG = "N" ARCHIVE_STATUS = "LOCALLY ARCHIVED" DATA_SET_TERSE_DESC = "Raw, uncalibrated spectra and ancillary files from the Odyssey GRS, NS, and HEND instruments." CITATION_DESC = "Boynton, W.V., Mars 2001 Odyssey Gamma Ray Spectrometer EDR Data V1.0, ODY-M-GRS-2-EDR-V1.0, NASA Planetary Data System, 2001." ABSTRACT_DESC = "Raw, uncalibrated spectra and ancillary files from the Odyssey GRS, NS, and HEND instruments." DATA_SET_DESC = " Data Set Overview ================= The Mars Odyssey Gamma-Ray Spectrometer (GRS) is a suite of three instruments working together to collect data that will permit the mapping of elemental concentrations on the surface of Mars. The suite of three instruments, the gamma sensor head (GS), the neutron spectrometer (NS) and the high-energy neutron detector (HEND), are a complementary set of instruments in that the neutron instruments have better counting statistics and sample to a greater depth than the GS, but the GS determines the abundance of many more elements. A full description of the Mars Odyssey Gamma-Ray Spectrometer instrument suite can be found in [BOYNTONETAL2004]. The ODY MARS GAMMA RAY SPECTROMETER 2 EDR (GRSEDR) data set is a time series collection of GS, NS, HEND, calibration, engineering, and commanding measurements from the Mars Odyssey spacecraft. Data are sorted by type and by time. Data types included in this data set are gamma spectra, neutron spectra, hend spectra, pulser, profile, engineering, channelized, command list, message log, and e-kernel data types. Data are sorted by time, with each data file containing one day's worth of data from midnight to midnight UTC. Measurements are assigned to a particular day based on the end of the collection interval. The GRS collects a new spectrum (pixel) approximately every 20 seconds, 360 times per orbit. Approximately 4200 spectra are expected to be received every day. The data (both science and engineering) are downloaded from the spacecraft by the Jet Propulsion Laboratory (JPL) into the Telemetry Data System (TDS). The TDS sends data to a process that translates data packets and examines instrument health via messages. Data are output to a spooler that passes them to the University of Arizona (UA) database ingest process. The ingest process inputs raw data into the UA database. Data are retrieved from the UA database to build the GRSEDR data products. The GRSEDR data set is intended to be the lowest level (level 0) data available for the GRS. It should be useful to those scientists who are experienced in gamma or neutron spectroscopy. Parameters ========== The GRSEDR data set is composed of three main data types and seven supporting data types. The objective of compiling the GRSEDR is to create a record of the primary data collected by the GRS. The following paragraphs discuss the parameters of interest in each of the data types. Gamma ----- The gamma data are time series records taken over the course of a day. Data files are labeled with the date. Individual records are a single data collection interval, which lasts approximately 20 seconds. Gamma data are the science data produced by the GS. NS -- The NS data are time series records taken over the course of a day. Data files are labeled with the date. Individual records are a single data collection interval, which lasts approximately 20 seconds. NS data are the science data produced by the NS. HEND ---- The HEND data are time series records taken over the course of a day. Data files are labeled with the date. Individual records are a single data collection interval, which lasts approximately 20 seconds. HEND data are the science data produced by HEND. The Message Log, Command List, Pulser Spectra, Engineering and Channelized data sets provide supporting information. Message Log ----------- The Message Log data are time series records taken over the course of a day. Data files are labeled with the date. Individual records are a single data collection interval, which lasts approximately 20 seconds. The Message Log data are messages returned from the GRS central electronics box (CEB). Command List ------------ The Command List data are time series records taken over the course of a day. Data files are labeled with the date. Individual records are a single data collection interval, which lasts approximately 20 seconds. Command List data are records of the commands issued to the file interchange system (FIS) for up-link to the spacecraft and executed by the CEB. Pulser Spectra -------------- The Pulser Spectra data are time series records taken over the course of a day. Data files are labeled with the date. Individual records are a single data collection interval, which lasts approximately 20 seconds. Pulser data are internal GS calibration data. Engineering Data ---------------- The Engineering data are time series records for each engineering parameter taken over the course of a day. Data files are grouped in the ENG folder and are labeled with the engineering parameter name. Individual records are a single data collection interval that is variable in duration. Engineering values are reported by parameter name and include collection time, raw value, and engineering value, In general, temperatures are reported in Celsius, currents in amps, and potentials in volts. The ENG_DATA label file is the definitive source for the units of measure. Engineering values are specific monitor values recorded by the GRS CEB. Channelized Data ---------------- Channelized data are time series records taken over the course of a day. Data files are grouped in the CHAN folder and are labeled with the channelized parameter name. Individual records are a single data collection interval, which is variable in duration. Channelized data values are reported by type, and contain the processed channelized value. Channelized values are different than engineering values in that they are recorded by the spacecraft computer and are received and processed by JPL, and then ingested into the UA database. Processing ========== GRS data (both science and engineering) are downloaded from the Mars Odyssey spacecraft by JPL into the Telemetry Data System (TDS). The TDS sends the data to a process called GRS_tl, which translates GRS packets from any source to any destination and examines instrument health via messages. The data are checked for packet types, header information, messages, errors, engineering and channelized data values and are output to a spooler, which passes data to the UA database ingestion process. The ingestion process inputs raw data into the database. The initialization of the ingestion process sets up the necessary connections to the SPICE kernel information (Navigation and Ancillary Information Facility (NAIF) system designed to provide scientists with ancillary observation geometry data useful in interpretation of science instrument observations returned from planetary spacecraft), the database, and the input data. The appropriate SPICE kernels are loaded and opened, and a connection is initiated with the database. Command line options are then read, and the data ingestion begins. A function reads the data header to get the total number of bytes in the packet, and the sequence bytes. The rest of the packet is then read. The data type, read from the common header, is returned, determining the next step in the processing. One of eighteen different procedures is run to insert packet data into the appropriate database tables. If the data type returned is less than or equal to 0 an error message is returned stating that the packet was not inserted. All data packets are processed for timing and spatial information. Once time data are extracted from the data packet, UTC time is calculated from the spacecraft event time (sc_ev_time, time at the middle of the collection interval) by a SPICE function. The UTC time is then inserted into the database. The spatial portion of the data packet is calculated using another SPICE routine. The returned values are all the spatial elements of an observation, including latitude and longitude at the mid-point of the observation. Engineering values have an additional step of processing. Raw engineering values (digital) are converted to engineering unit values by scaling the raw value with a stored polynomial. The polynomials were derived through hardware calibrations, and are calculated by a series of database triggers. See the Gamma Processing document for a table of the engineering conversions. Data ==== The GRSEDR data set is composed of a series of date stamped files that contain 1 day's worth (24 hours, 00:00:00 UTC to 23:59:59 UTC) of data for 10 different data types. The following sections describe each data type. Gamma Spectra ------------- Gamma Spectra data are composed of raw gamma spectra and the associated timing and spatial information. The gamma spectra consists of the cumulative counts of gamma rays at the detector over one collection interval binned into 16384 channels based on energy. The collection interval is approximately 19.7 seconds, but may vary over the course of mapping. The timing and spatial data provided with the gamma spectra includes spacecraft clock values and spacecraft geometry data. The sc_ev_time, UTC time and spatial fields are all recorded at the center of the collection interval. Neutron Spectra --------------- Neutron Spectra data are composed of 15 histograms, event data and the associated timing and spatial information. The neutron event data are the cumulative counts of neutrons detected at 1 of four prisms over the collection interval. The collection interval is approximately 19.7 seconds, but may vary over the course of mapping. The timing and spatial data provided with the neutron spectra includes spacecraft clock values and spacecraft spatial data. The sc_ev_time, UTC time and geometry fields are all recorded at the center of the collection interval. Hend Spectra ------------ HEND Spectra data are composed of HEND records and the associated timing and spatial information. HEND records (frames) can be one of three types: nominal (spectra), profile (time series), or status (commands). The nominal frame consists of six spectra, with 16 channels, two bytes per channel. The profile frame consists of the six spectra plus two time profiles. The inner scintillator profile is thirty seconds in duration, with a count for each second. The outer scintillator profile is also thirty seconds in duration, but has a time resolution of 0.25 seconds, with a count for each interval. The timing and spatial data provided with the HEND data includes spacecraft clock values and spacecraft geometry data. The sc_ev_time, UTC time and spatial fields are all recorded at the center of the collection interval. Pulser Spectra -------------- Pulser Spectra are composed of the GS derived spectra of three artificially produced pulses of energy as well as associated timing and spatial information. During the normal gamma spectrum collection voltage pulses of known amplitude, and a flag labeling them as pulsers, are sent to the GS detector at a frequency of 10Hz. These are interpreted by the detector as events and binned in the appropriate channels, but saved in a separate memory location. Pulser spectra are used to evaluate the frequency response and drift of the GS detector and electronic components as functions of instrument temperatures, voltages, and other variables. Profile Data ------------ Profile data are an array of the raw gamma events continuously binned at high time resolution and limited energy resolution. The array length, settable up to 2048 elements, covers the duration of the current pixel. Each element contains four scalars which represent the counts above the Lower Level Discriminator (LLD), between LLD and L1, between L1 and L2, and between L2 and L3. The parameters LLD, L1, L2, and L3 are all settable parameters. These data are sent from the CEB when a gamma-ray burst is detected. At the time of detection the current pixel's profile data along with additional pixel sets are packaged for downlink. The total number of additional sets is a settable parameter and is currently set to 2. Engineering Data ---------------- Engineering data are composed of the 67 different engineering readings monitored in the GRS, and the associated timing information. The engineering readings can be taken at several different time intervals, which can be changed depending on spacecraft operation. Times associated with the individual readings can be used to determine the sampling intervals. The following is a list of all the engineering readings and a description of each. 0 CEB_AGND - central electronics box analog ground 1 CEB_PLUS_5_CRYO - central electronics box plus 5 volt cryogenic diode sensor reference voltage 2 CEB_PS1_TEMP - central electronics box power supply temperature sensor 1 3 CEB_CPU_TEMP - central electronics box CPU clock temperature sensor 4 CEB_IS_TEMP_A - gamma cooler inner stage temperature sensor 5 CEB_OS_TEMP_A - gamma cooler outer stage temperature sensor 6 CEB_MNT_RNG_TEMP_A - gamma cooler mounting ring temperature A sensor 7 CEB_HTR_CNTRL_TEMP - central electronics box power control board temperature sensor 8 CEB_CPU_PLUS_5 - central electronics box CPU +5 volt bus sensor 9 CEB_CPU_PLUS_5_CURR - central electronics box central processing unit +5 volt bus current sensor 10 CEB_PS2_TEMP - central electronics box power supply temperature sensor 2 11 CEB_IS_TEMP_B - gamma cooler inner stage temperature B sensor 12 CEB_OS_TEMP_B - gamma cooler outer stage temperature B sensor 13 CEB_MINUS_12V_CEB_AN - central electronics box -12 volt analog supply bus voltage 14 CEB_MNT_RNG_TEMP_B - gamma cooler mounting ring temperature B sensor 15 CEB_PLUS_12V_CEB_AN - central electronics box +12 volt analog supply bus voltage 16 CEB_PLUS_28_CURR - central electronics box main +28 volt supply bus current readings 17 CEB_ALT_ACTUATOR_CURR - central electronics box alternate +28 volt supply bus current 18 CEB_SPARE_CURR_SENSE_2 - central electronics box spare current sensor 2 19 CEB_SPARE_CURR_SENSE_3 - central electronics box spare current sensor 2 20 CEB_PC_CURR_REF - central electronics box power control board current sensor reference voltage 21 CEB_AGND_SPARE1 - central electronics box analog ground spare 1 22 CEB_AGND_SPARE2 - central electronics box analog ground spare 2 23 CEB_AGND_SPARE3 - central electronics box analog ground spare 3 24 CEB_PS_CURR_REF - central electronics box power supply board current sensor reference voltage 25 CEB_MAIN_ACTUATOR_CURR - central electronics box main +28 volt bus actuator current 26 CEB_AD_TEMP - central electronics box analog to digital converter temperature sensor 27 GAMMA_ELEC_FAST - gamma detector electrometer fast readings 28 GAMMA_ELEC_SLOW - gamma detector electrometer slow readings 29 GAMMA_PLUS_12V_RAIL_VOLT - gamma subsystem +12 volt analog bus voltage monitor 30 GAMMA_PLUS_12V_RAIL_CRNT - gamma subsystem +12 volt analog bus current monitor 31 GAMMA_MINUS_12V_RAIL_VOLT - gamma subsystem -12 volt analog bus voltage monitor 32 GAMMA_MINUS_12V_RAIL_CRNT - gamma subsystem -12 volt analog bus current monitor 33 GAMMA_PLUS_5V_DIG_RAIL_VOLT - gamma subsystem +5 volt digital bus voltage monitor 34 GAMMA_PLUS_5V_DIG_RAIL_CRNT - gamma subsystem +5 volt digital bus current monitor 35 GAMMA_PLUS_12V_HVBS_RAIL_CRNT - gamma high voltage bias supply +12 volt bus current monitor 36 GAMMA_MINUS_12V_HVBS_RAIL_CRNT - gamma high voltage bias supply -12 volt bus current monitor 37 GAMMA_PLUS_12V_PULSE_AMP_CRNT - gamma preamplifier +12 volt bus current 38 GAMMA_MINUS_12V_PULSE_AMP_CRNT - gamma preamplifier -12 volt bus current 39 GAMMA_VDD_DIRECT_MNTR - gamma subsystem +5 digital bus voltage monitor 40 GAMMA_REF_VOLT_166 - gamma subsystem 1.66 reference voltage 41 GAMMA_REF_VOLT_333 - gamma subsystem 3.33 reference voltage 42 GAMMA_REF_VOLT_500 - gamma subsystem 5.00 reference voltage 43 GAMMA_DAC_0 - gamma subsystem digital to analog converter 0 output voltage. (Low level discriminator threshold setting) 44 GAMMA_DAC_1 - gamma subsystem digital to analog converter 1 output voltage. (L1 discriminator threshold setting) 45 GAMMA_DAC_2 - gamma subsystem digital to analog converter 2 output voltage. (L2 discriminator threshold setting) 46 GAMMA_DAC_3 - gamma subsystem digital to analog converter 3 output voltage. (L3 discriminator threshold setting) 47 GAMMA_DAC_4 - gamma subsystem digital to analog converter 4 output voltage. (Upper level discriminator threshold setting) 48 GAMMA_DAC_5 - gamma subsystem digital to analog converter 5 output voltage. (Spare channel) 49 GAMMA_DAC_6 - gamma subsystem digital to analog converter 6 output voltage. (Spare channel) 50 GAMMA_DAC_7 - gamma subsystem digital to analog converter 7 output voltage. (High voltage bias supply setting) 51 GAMMA_HVBS_MNTR - gamma high voltage bias supply output voltage monitor 52 GAMMA_SPARE_1 - gamma subsystem spare channel 1 53 GAMMA_HVBS_ENABLE_MNTR - gamma high voltage bias supply enable monitor 54 GAMMA_VREF_TEMP - gamma subsystem voltage reference temperature reading 55 GAMMA_GPA_TEMP - gamma preamplifier temperature readings 56 GAMMA_HVBS_TEMP - gamma high voltage bias supply temperature 57 GAMMA_SPARE_2 - gamma subsystem spare channel 2 58 GAMMA_MUX_OFFSET - gamma subsystem analog ground reference measurement 59 PLUS_5V_ANLG - neutron spectrometer + 5 volt analog bus voltage readings 60 MINUS_5V_ANLG - neutron spectrometer -5 volt analog bus voltage readings 61 PLUS_5V_CRNT_ANLG - neutron spectrometer +5 volt analog bus current readings 62 MINUS_5V_CRNT_ANLG - neutron spectrometer -5 volt analog bus current readings 63 PLUS_5V_CRNT_DIG - neutron spectrometer +5 volt digital bus current readings 64 HVPS_MNTR_1 - neutron spectrometer high voltage power supply #1 monitor 65 HVPS_MNTR_2 - neutron spectrometer high voltage power supply #2 monitor 66 PREAMP_TEMP - neutron spectrometer preamplifier temperature Channelized Data ---------------- The Channelized data are 26 engineering readings from the spacecraft, and the associated timing values. These data are taken by the spacecraft, and sampling intervals are set by the JPL spacecraft team. Some of the channelized readings are only recorded when there is a change in the setting, whereas others are sampled on a regular interval. The following is a list of the names and descriptions of the channelized data. Future data releases may contain a different set of channelized readings. 0 GRS_AD_EN_ST - Status of the enable state. 1 GRS_ANDR_ST - GRS Anneal Door Status 2 GRS_ANNEAL - Instructs the enabling or disabling of the GRS anneal process. 3 GRS_BOOT_ST - Boot select discrete status 4 GRS_CEB_TMP - CEB temperature 5 GRS_GPA_TMP - Gamma GPA temperature 6 GRS_GSH_TMP - Gamma sensor head temperature 7 GRS_HB_CTR - Number of total heartbeats received from the GRS 8 GRS_HB_LT_C - Spacecraft time of last heartbeat (coarse reading in seconds) 9 GRS_HEND_TMP - GRS temp HEND. 10 GRS_HFTLP_EN - Enable status for GRS_HFTL_P_EXEC command to be processed. 11 GRS_HFTLP_EX - HFTL primary execute duration 12 GRS_HFTLS_EN - Enable status for GRS_HFTL_S_EXEC command to be processed. 13 GRS_HFTLS_EX - HFTL secondary execute duration 14 GRS_HT_CRR - Number of heartbeats from last power-on or last boot or last system 15 GRS_NS_TMP - Neutron Spectrometer temperature 16 GRS_PWR_NCTR - Number of times the GRS power notification command is sent 17 GRS_RST_CTR - Number of times GRS has been reset 18 GRS_SYNC_T_C - Synch of spacecraft clock and GRS central electronics box clock 19 GRS_SYN_CTR - Number of times GRS has been synched 20 HND_PWR_NCTR - Number of times the Hend power notification command is sent 21 RPC_1_CUR - GRS main current monitor 22 RPC_3_CUR - GRS HEND current monitor 23 RPC_8_CUR - GRS replacement heater monitor current 24 RPC_8_VLT - GRS replacement heater monitor voltage 25 RPC_9_CUR - GRS alternate current Command List ------------ The Command List data are a record of the commands that have been sent to or executed from the spacecraft and the associated timing information. Command data are produced whenever a command is executed. Timing information is stored with the commands, indicating when the command was sent to the spacecraft, the time the command should have been executed, and when the command was executed. Message Log ----------- The Message Log data consists of the data sent from the CEB in response to some action taking place in the GRS and the associated timing information. The message data includes general messages and warnings as well as CEB error messages. The frequency of message data depends on CEB activity. The timing information (sc_ev_time and UTC time) for each message is associated with the actual time the message was produced. E-Kernel -------- The E-Kernel data consists of the Experimenter's Notes, the list of commands sent, and the associated timing information. These data are produced in response to a set of commands being placed on the FIS. Ancillary Data ============== Ancillary data are listed by data type. Command List ------------ A list of all command Op codes and the commands they correspond to can be found in the Command list label file, or can be found in the grs_command_dict document located in the document directory. Message Log ----------- A list of all message ID's and their associated meanings can be found in the Message Log label file. A list of message detail ID's and the associated information can be found in the grs_message_dict document located in the document directory. E-Kernel -------- The information in the command list section above applies to this data also. Coordinate System ================= The coordinate system used for all GRS data is a Mars areocentric system following the IAU convention [SEIDELMANNETAL2002], with east longitudes from 0 to 360. Software ======== A library of source code to parse the GRSEDR data product files is included in the software directory. This library allows a programmer to build applications that display or manipulate GRSEDR data. This source is written in the Java language, and requires version 1.3 of the Java Runtime Environment (JRE) or Java Software Development Kit (SDK). Documentation for the code is located in the software directory in the file GRS_CODE_DOC.ZIP. The contents of this file are described in the label GRS_CODE_DOC.LBL and the source and the binary classes that make up the library are in the file EDR_CODE.JAR. Media/Format ============ The GRSEDR will be delivered using DVD media. Formats will be based on standards for such products established by the Planetary Data System (PDS) [PDSSR2001]." CONFIDENCE_LEVEL_NOTE = " Confidence Level Overview ========================= The data presented in the GRSEDR is intended to be the least processed, most primitive data set released for the GRS. Data presented here are an accurate representation of the GRS data as received from the spacecraft, with minimal timing and spatial processing. The usefulness of this data is limited by two significant factors; the large volume of data with a small signal-to-noise ratio, and the necessity of correcting gamma data for a common energy scale. Review ====== The GRSEDR was reviewed internally by the GRS team prior to release to the PDS. PDS also performed an external review of the GRSEDR. Data Coverage and Quality ========================= Data reported are the minimally processed data received from the spacecraft during the three mission stages: cruise, aerobraking and mapping. Data coverage and quality are addressed in the following sections. Cruise ------ The Cruise portion of the mission lasted from launch, April 07, 2001 to October 23, 2001. Spacecraft power was turned on to the CEB, on April 25, 2001, and the GS, NS and HEND were powered on May 02, 2002. GS data were collected on and off during the period May 2, 2001 to September 4, 2001. NS and HEND data were collected on and off during the period from May 2, 2001 to September 24, 2001. All GRS systems were shut down for Mars orbital insertion on September 24, 2001. During Cruise the GRS high voltage was ramped down on August 15, 2001 to August 17, 2001 due to a solar particle event. During this period no high voltage data were collected. Other short data outages occurred on July 26, 2001 and September 6, 2001 due to software re-sets. There may also be other periods of missing data during the Cruise mission phase. These short outages, called data gaps, are due to missing telemetry and cannot be recovered. Aerobraking ----------- The Aerobraking portion of the mission lasted from October 24, 2001 to February 18, 2002. Science data (GS, NS, HEND) were collected for the first 2 days of the Aerobraking mission phase. On October 26, 2001 the spacecraft was placed in safe mode, and the GRS was shut down until November 16, 2001. Science data were then collected on and off from November 16, 2001, to December 19, 2001. On December 19 the GRS was shut down until January 14, 2002. Science data were collected from January 14, 2002, until February 18, 2002, with a short data outage on February 15. During the aerobraking mission phase there may be short periods of missing data due to missing telemetry. Primary Mapping --------------- The Mapping portion of the mission began February 19, 2002, and is expected to last until August, 2004. Primary mapping is broken into two phases based on the GRS instrument configuration: stowed mapping and deployed mapping. Stowed Mapping -------------- The stowed mapping configuration began on February 19, 2002 and lasted until June 1, 2002. The stowed mapping configuration is with the Odyssey spacecraft in a mapping orbit, with the GRS in data collection configuration without the 6-meter boom deployed. The GS is located at the end of the 6-meter boom in order to reduce background from the spacecraft. GS data was collected before the boom was deployed to measure the background signal from the spacecraft. The NS and HEND instruments are not affected by the boom configuration. During the stowed mapping portion of the mission, two anneals were performed on the gamma detector. The anneals were performed between March 8, 2002, and March 22, 2002, and between May 6, 2002, and May 20, 2002. No gamma science data were collected during these two periods. On June 1, 2002 the GS was shut down to prepare for boom deployment, which occurred on June 4, 2002. Again, no gamma science data was collected during this period. During the stowed mapping phase there may be short periods of missing data due to missing telemetry that cannot be recovered. Deployed Mapping ---------------- Deployed Mapping began on June 5, 2002 and ran through the end of primary mission (August, 2004). Deployed Mapping continued in extended mission 1, which runs from August 2004 until August 2006. All science data collected during these times are suspect due to solar particle events (SPE): 07/16/02 17:00:00 to 07/24/02 12:00:00 10/14/02 15:00:00 to 10/17/02 03:00:00 10/25/02 10:15:00 to 10/27/02 00:00:00 10/28/02 00:00:00 to 11/02/02 00:00:00 03/18/03 15:00:00 to 03/21/03 00:00:00 05/31/03 00:00:00 to 06/02/03 00:00:00 10/26/03 18:00:00 to 10/28/03 11:05:00 10/28/03 11:05:00 to 10/29/03 07:40:00 07/06/04 00:00:00 to 07/09/04 12:00:00 09/12/04 03:30:00 to 09/14/04 17:30:00 11/11/04 11:45:00 to 11/19/04 00:00:00 01/19/05 13:23:37 to 01/26/05 00:09:03 02/01/05 10:50:00 to 02/03/05 22:49:43 06/16/05 21:54:00 to 06/20/05 00:00:00 07/14/05 14:30:00 to 07/17/05 14:30:00 07/17/05 14:30:00 to 07/19/05 02:30:00 07/24/05 22:00:00 to 07/26/05 00:00:00 08/23/05 13:08:31 to 08/25/05 22:40:48 08/29/05 12:00:00 to 09/04/05 23:59:56 09/07/05 19:59:56 to 09/16/05 05:59:56 All science data collected during solar flare events are also suspect: 07/16/02 15:54:02 to 07/16/02 16:05:13 10/14/02 14:25:39 to 10/14/02 14:38:29 10/27/02 22:58:30 to 10/27/02 23:24:00 03/29/03 11:45:16 to 03/29/03 11:47:54 04/06/03 22:36:53 to 04/06/03 22:39:51 04/21/03 13:09:17 to 04/21/03 13:14:34 04/25/03 15:48:08 to 04/25/03 15:58:00 05/28/03 00:26:59 to 05/28/03 00:37:31 10/22/03 20:12:49 to 10/22/03 20:17:26 10/23/03 08:26:23 to 10/23/03 08:54:30 10/24/03 02:47:45 to 10/24/03 03:05:52 10/26/03 07:04:36 to 10/26/03 07:50:23 10/26/03 17:32:00 to 10/26/03 18:00:00 Gamma data collected these dates are suspect due to temperature fluctuations in the gamma subsystem: 06/19/02 18:00:00 to 06/20/02 18:00:00 07/08/02 18:15:00 to 07/08/02 20:00:00 07/15/02 15:45:00 to 07/16/02 17:00:00 07/23/03 23:28:00 to 07/24/03 17:00:00 09/29/03 21:55:00 to 09/30/03/00:55:00 11/28/03 07:20:00 to 11/28/03 17:00:00 12/02/03 14:30:00 to 12/02/03 15:30:00 12/11/03 16:15:00 to 12/11/03 20:30:00 04/25/05 19:02:00 to 04/26/05 00:00:00 04/26/05 00:00:00 to 04/30/05 00:00:00 No science data were collected during these times due to spacecraft safe modes: 11/05/02 01:50:00 to 11/13/02 18:45:00 10/29/03 07:40:40 to 11/07/03 18:40:00 04/02/05 22:33:48 to 04/07/05 23:06:00 03/22/06 07:54:00 to 03/26/06 03:30:00 Gamma data collected over the time intervals 11/05/02 01:48:04 to 11/28/02 08:00:00 10/29/03 07:40:40 to 11/28/03 07:20:00 04/02/05 22:33:48 to 04/25/05 19:02:00 03/26/06 03:30:00 to 03/30/06 18:34:24 are suspect due to a safe mode of the spacecraft, and the subsequent high temperature anneal of the gamma detector. Any single spectrum with a bad code greater than 0 should be treated with caution, as it may not be suitable for further processing. Refer to the Auto_Bad section in the Mars Odyssey Gamma-ray Spectrometer Gamma Data Processing.pdf document located in the documents folder that accompanies this release for further details. There are short data gaps due to missing telemetry that cannot be recovered. Limitations =========== The major limitation of this data set is that this is level 0, minimally processed data. The data are received from the spacecraft telemetry and ingested into a database. If gaps exist in the telemetry, data are lost. Timing and spatial components of the data rely on the accuracy of the NAIF SPICE kernels. Data Compression =============== Gamma Spectra ------------- Gamma spectra are compressed in the CEB then decompressed when received on the ground. The compression algorithm is a lossless compression. See the document grs_gamma_compression in the document directory for the algorithm. Neutron Spectra --------------- NS data are compressed using a lossy compression algorithm. The compression algorithm is given in the neutron_compression document in the document directory. Hend Spectra ------------ No compression is used on HEND spectra. Pulser Spectra -------------- Pulser spectra are compressed in the CEB and decompressed when received on the ground. The compression algorithm is a lossless compression. See grs_gamma_compression in the document directory for the algorithm. Profile Data ------------ Profile Data are compressed in the CEB and decompressed when received on the ground. The compression algorithm is a lossless compression. See grs_gamma_compression in the document directory for the algorithm. " END_OBJECT = DATA_SET_INFORMATION OBJECT = DATA_SET_TARGET TARGET_NAME = MARS END_OBJECT = DATA_SET_TARGET OBJECT = DATA_SET_HOST INSTRUMENT_HOST_ID = "ODY" INSTRUMENT_ID = "GRS" END_OBJECT = DATA_SET_HOST OBJECT = DATA_SET_REFERENCE_INFORMATION REFERENCE_KEY_ID = "BOYNTONETAL2004" END_OBJECT = DATA_SET_REFERENCE_INFORMATION OBJECT = DATA_SET_REFERENCE_INFORMATION REFERENCE_KEY_ID = "SEIDELMANNETAL2002" END_OBJECT = DATA_SET_REFERENCE_INFORMATION OBJECT = DATA_SET_REFERENCE_INFORMATION REFERENCE_KEY_ID = "PDSSR2001" END_OBJECT = DATA_SET_REFERENCE_INFORMATION END_OBJECT = DATA_SET END