urn:nasa:pds:odyssey_grs_edr:data_science_raw:neutron_spectra_20250412 1.0 1.19.0.0 Product_Observational 2025-12-15 1.0 Release 94 2025-04-12T00:00:18.193Z 2025-04-12T23:59:55.497Z MARS Odyssey Mission urn:nasa:pds:context:investigation:mission.2001_mars_odyssey data_to_investigation 2001 MARS ODYSSEY Host urn:nasa:pds:context:instrument_host:spacecraft.ody is_instrument_host NEUTRON SPECTROMETER Instrument urn:nasa:pds:context:instrument:ody.ns is_instrument Mars Planet urn:nasa:pds:context:target:planet.mars data_to_target 94 NEUTRON_SPECTRA 1.0 EXTENDED MISSION 365794352957 365816465565 neutron_spectra_20250412.dat neutron_spectra_data_table 2025-12-15T17:42:19.201 0 4372 This the raw uncalibrated neutron detector counts and associated data. 32 23 2024 SC_RECV_TIME 1 1 UnsignedMSB8 8 The time this packet was received by the spacecraft, in ticks (256 per second). SC_EV_TIME 2 9 UnsignedMSB8 8 Spacecraft time at the middle of the pixel, in ticks. CEB_TIME 3 17 UnsignedMSB8 8 ms Clock count from the GRS Common Electronics Box at the beginning of the pixel. UTC 4 25 ASCII_String 23 SC_EV_TIME converted to UTC, stored as yyyy-mm-ddThh:mm:ss.sss. GRS_PIXEL_NUMBER 5 48 UnsignedMSB4 4 Sequential counter of accumulation intervals, starts with one as grs orbit begins. Special case on reboot when the the CEB is in orbit 0, pixel 0. 0 GRS_ORBIT_NUMBER 6 52 UnsignedMSB4 4 Sequential counter of orbits from GRS CEB boot. 0 ODY_ORBIT_NUMBER 7 56 UnsignedMSB4 4 Orbit number common to all instruments aboard Odyssey. This orbit number is incremented by one as the spacecraft passes through the orbital descending node. 0 LATITUDE 8 60 IEEE754MSBDouble 8 Sub spacecraft latitude in Mars fixed coordinates at the middle of the pixel. LONGITUDE 9 68 IEEE754MSBDouble 8 Sub spacecraft longitude in Mars fixed coordinates at the middle of the pixel. 1 3 1 0 The geometric position (x,y,z) of the spacecraft with respect to Mars in the 'MARSIAU' inertial frame at the input epoch 'et' at the middle of the pixel. 76 24 SCPOS_INERT 1 1 IEEE754MSBDouble 8 km 2 3 1 0 The geometric velocity (x,y,z) of the spacecraft with respect to Mars in the 'MARSIAU' inertial frame at the input epoch 'et' at the middle of the pixel. 100 24 SCVEL_INERT 1 1 IEEE754MSBDouble 8 km/s 3 3 1 0 The (x,y,z) position of the sub-spacecraft point as seen from the spacecraft in the instrument frame at the middle of the pixel. If no spacecraft orientation data was available from the loaded CK files for the request time, then all elements of are set to zero. 124 24 MARSPOS_INSTR 1 1 IEEE754MSBDouble 8 km 4 3 1 0 Contains the inertial spacecraft velocity direction (x,y,z) rotated to the instrument frame at the middle of the pixel. If no spacecraft orientation data was available for the request time, then all elements are set to zero. 148 24 MARSVEL_INSTR 1 1 IEEE754MSBDouble 8 km/s 5 3 1 0 Spacecraft position (x,y,z) in Mars fixed coordinates at the middle of the pixel. 172 24 SCPOS_MARS 1 1 IEEE754MSBDouble 8 km 6 3 1 0 Sub instrument boresight (x,y,z) in Mars fixed coordinates at the middle of the pixel. 196 24 INSTR_BORESIGHT_MARS 1 1 IEEE754MSBDouble 8 km 7 3 1 0 Sub spacecraft vector (x,y,z) in Mars fixed coordinates at the middle of the pixel. 220 24 SUB_SCPOS_MARS 1 1 IEEE754MSBDouble 8 km SCALT 10 244 IEEE754MSBDouble 8 km Areocentric altitude of the sub-spacecraft point in Mars-fixed rotating frame at the middle of the pixel. DELTA_ANGLE 11 252 IEEE754MSBDouble 8 degrees Difference between instrument +y direction and true north at the middle of the pixel. Currently not computed for NEUTRON_SPECTRA and HEND_SPECTRA. MARS_SOL 12 260 IEEE754MSBDouble 8 Longitude of the Sun at 0 hours UT on the date of the record. Taken from the Association of Lunar and Planetary Observers 'Ephemeris for Physical Observation of Mars'. DAY_INDEX 13 268 UnsignedMSB2 2 Day of Martian year. LOCAL_HOUR 14 270 UnsignedByte 1 Local Sun hour at the sub-spacecraft point. LOCAL_MINUTE 15 271 UnsignedByte 1 Local Sun minute at the sub-spacecraft point. POINTING 16 272 UnsignedByte 1 1 = True -- pointing data available. INTERSECTING 17 273 UnsignedByte 1 1 = True -- the pointing vector intersects Mars. BAD_CODE 18 274 UnsignedMSB4 4 If non-zero, the data has been flagged bad. Definitions in bad_code.txt. COUNTER 19 278 UnsignedByte 1 The packet counter from the lanl pkt, values from 0 to 15. NS_COMPRESSED 20 279 UnsignedByte 1 indicates if LANL compression algorithm was used on this data. GRS_COMPRESSED 21 280 UnsignedByte 1 indicates if GAMMA compression algorithm was used on this data. NS_INSTRUMENT_MEMORY_SIDE 22 281 UnsignedMSB2 2 Memory side data is coming from. EARLY_TIME 23 283 UnsignedMSB2 2 Early time register. LATE_TIME 24 285 UnsignedMSB2 2 Late time register. DEAD_CNT 25 287 UnsignedMSB8 8 Dead count. GCR_CNT 26 295 UnsignedMSB2 2 Galactic cosmic ray count. EARLY_2ND_PULSE_CNT 27 297 UnsignedMSB2 2 Early time to second pulse count. CAT1_3SEG_CNT 28 299 UnsignedMSB2 2 Category 1, 3 prism event count CAT1_4SEG_CNT 29 301 UnsignedMSB2 2 Category 1, 4 prism event count CAT2_3SEG_CNT 30 303 UnsignedMSB2 2 Category 2, 3 prism event count CAT2_4SEG_CNT 31 305 UnsignedMSB2 2 Category 2, 4 prism event count CAT2_CNT 32 307 UnsignedMSB2 2 Category 2 event count. 8 64 1 0 Category 1 histogram 1. 309 128 CAT1_1_HIST 1 1 UnsignedMSB2 2 9 64 1 0 Category 1 histogram 2. 437 128 CAT1_2_HIST 1 1 UnsignedMSB2 2 10 64 1 0 Category 1 histogram 3. 565 128 CAT1_3_HIST 1 1 UnsignedMSB2 2 11 64 1 0 Category 1 histogram 4. 693 128 CAT1_4_HIST 1 1 UnsignedMSB2 2 12 64 1 0 Category 1 summation histogram. 821 128 CAT1_SUM_HIST 1 1 UnsignedMSB2 2 13 16 1 0 Category 2 early time histogram 1. 949 32 CAT2_EARLY_1_HIST 1 1 UnsignedMSB2 2 14 16 1 0 Category 2 early time histogram 2. 981 32 CAT2_EARLY_2_HIST 1 1 UnsignedMSB2 2 15 16 1 0 Category 2 early time histogram 3. 1013 32 CAT2_EARLY_3_HIST 1 1 UnsignedMSB2 2 16 16 1 0 Category 2 early time histogram 4. 1045 32 CAT2_EARLY_4_HIST 1 1 UnsignedMSB2 2 17 16 1 0 Category 2 early time summation histogram. 1077 32 CAT2_EARLY_SUM_HIST 1 1 UnsignedMSB2 2 18 16 1 0 Category 2 late time histogram 1. 1109 32 CAT2_LATE_1_HIST 1 1 UnsignedMSB2 2 19 16 1 0 Category 2 late time histogram 2. 1141 32 CAT2_LATE_2_HIST 1 1 UnsignedMSB2 2 20 16 1 0 Category 2 late time histogram 3. 1173 32 CAT2_LATE_3_HIST 1 1 UnsignedMSB2 2 21 16 1 0 Category 2 late time histogram 4. 1205 32 CAT2_LATE_4_HIST 1 1 UnsignedMSB2 2 22 16 1 0 Category 2 late time summation histogram. 1237 32 CAT2_LATE_SUM_HIST 1 1 UnsignedMSB2 2 EVENTS_ARRAY 23 84 5 0 Events mode data is the first 84 prism events in each accumulation period. 1269 756 TTSP 1 1 UnsignedMSB2 2 Time to second pulse. DELAY_HITS 2 3 UnsignedByte 1 Delayed segment id, 0 if a single-prism event, 1 for multiple-prism event. PRISM_ID 3 4 UnsignedByte 1 1 = prism segment 1 only, 2 = prism segment 2 only, 3 = prism segment 3 only, 4 = prism segment 4 only, 5 = multiple prism event. DELAY 4 5 UnsignedByte 1 Delayed interaction pulse height. PROMPT 5 6 UnsignedMSB4 4 Prompt interaction pulse height. neutron_spectra_20250412.lbl 0 PDS3 PDS3 label Carriage-Return Line-Feed