urn:nasa:pds:odyssey_grs_edr:data_science_raw:hend_spectra_20250412 1.0 1.19.0.0 Product_Observational 2025-12-15 1.0 Release 94 2025-04-12T00:00:18.356Z 2025-04-12T23:59:55.937Z 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 HIGH ENERGY NEUTRON DETECTOR Instrument urn:nasa:pds:context:instrument:ody.hend is_instrument Mars Planet urn:nasa:pds:context:target:planet.mars data_to_target 94 HEND_SPECTRA 1.0 EXTENDED MISSION 365794352999 365816465678 hend_spectra_20250412.dat hend_spectra_data_table 2025-12-15T17:39:27.695 0 4372 This the raw uncalibrated hend spectra and associated data. HEND records or frames, can be of three types: spectra (nominal), profile (burst), or status. The nominal frame consist of six spectra, with 16 channels, two bytes per channel. The profile frame consists of the six spectra plus two time profiles. 48 21 852 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 hend packet, values from 0 to 15. CHECKSUM 20 279 UnsignedMSB2 2 An XOR checksum of the packet from title through temps, put on the data by the HEND instrument. ANTICOINCIDENCE_CODE 21 281 UnsignedByte 1 Bit 1 represents the anticoincidence veto setting (on or off) for the signal from the outer scintillator versus neutrons from the inner scintillator. Bit 2 represents the anticoincidence veto setting (on or off) for the signal from the outer scintillator versus the background from the inner scintillator. Bit 3 represents the anticoincidence veto setting (on or off) for the signal from the inner scintillator versus the background from the outer scintillator. FRAME_NUMBER 22 282 UnsignedMSB2 2 HEND data frame number, aka packet counter. FRAME_TYPE 23 284 UnsignedByte 1 Type of frame, (status=0, spectra=2, profile=3). IN_CONTROL 24 285 UnsignedMSB2 2 The state of the In control discretes between the CEB and HEND. OUT_STATUS 25 287 UnsignedMSB2 2 The state of the Out status discretes between the CEB and the HEND. T1_T4_TEMP 26 289 UnsignedMSB2 2 Reading of temperature sensor 1 if even frame, temperature sensor 4 if odd. T2_T5_TEMP 27 291 UnsignedMSB2 2 Reading of temperature sensor 2 if even frame, temperature sensor 5 if odd. T3_T6_TEMP 28 293 UnsignedMSB2 2 Reading of temperature sensor 3 if even frame, temperature sensor 6 if odd. HV1_LVL 29 295 UnsignedByte 1 High Voltage #1 (LD) level. 0 = off, 1 = minimal level, 2 = optimal level, 3 = maximal level. HV2_LVL 30 296 UnsignedByte 1 High Voltage #2 (LD) level. 0 = off, 1 = minimal level, 2 = optimal level, 3 = maximal level. HV3_LVL 31 297 UnsignedByte 1 High Voltage #3 (SD) level. 0 = off, 1 = minimal level, 2 = optimal level, 3 = maximal level. HV4_LVL 32 298 UnsignedByte 1 High Voltage #4 (Inner) level. 0 = off, 1 = minimal level, 2 = optimal level, 3 = maximal level. HV5_LVL 33 299 UnsignedByte 1 High Voltage #5 (Outer) level. 0 = off, 1 = minimal level, 2 = optimal level, 3 = maximal level. TRIG_LOGIC 34 300 UnsignedByte 1 Triggering logic, (0=AND, 1=OR). TRIGGER_CNT 35 301 UnsignedMSB2 2 Count of triggers seen. TRIGGER_LVL_C1 36 303 UnsignedByte 1 Criteria code for profile 1 (inner scintillator). Trigger level in units of counts is 8 for C1 = 0, 16 for C1 = 2, ... 64 for C1=7. TRIGGER_LVL_C2 37 304 UnsignedByte 1 Criteria code for profile 2 (outer scintillator). Trigger level in units of counts is 32 for C2 = 0, 64 for C2 = 2, ... 256 for C2=7. TRIGGER_PERM_C1 38 305 UnsignedByte 1 1 = Trigger permission ON for profile1; 0 = Trigger permission OFF for profile1. TRIGGER_PERM_C2 39 306 UnsignedByte 1 1 = Trigger permission ON for profile2; 0 = Trigger permission OFF for profile2. T1 40 307 UnsignedMSB4 4 Time of previous SYNC signal/start of accumulation. T2 41 311 UnsignedMSB4 4 Time of last trigger as a 16 bit value. K1 42 315 UnsignedByte 1 Bitmask for total number of permitted triggering, 0=arbitrary, N=N successive triggers are permitted. TITLE 43 316 SignedMSB4 4 from the title field in the HEND packet. LD_DISCRIMINATOR 44 320 UnsignedByte 1 Large detector discriminator level. 0 = off, 1 = minimal level, 2 = optimal level, 3 = maximal level. MD_DISCRIMINATOR 45 321 UnsignedByte 1 Medium detector discriminator level. 0 = off, 1 = minimal level, 2 = optimal level, 3 = maximal level. SD_DISCRIMINATOR 46 322 UnsignedByte 1 Small detector discriminator level. 0 = off, 1 = minimal level, 2 = optimal level, 3 = maximal level. IN_DISCRIMINATOR 47 323 UnsignedByte 1 Inner discriminator level. 0 = off, 1 = minimal level, 2 = optimal level, 3 = maximal level. OUT_DISCRIMINATOR 48 324 UnsignedByte 1 Outer discriminator level. 0 = off, 1 = minimal level, 2 = optimal level, 3 = maximal level. 8 16 1 0 Large detector spectrum. 325 32 LD_SPECTRUM 1 1 UnsignedMSB2 2 9 16 1 0 Medium detector spectrum. 357 32 MD_SPECTRUM 1 1 UnsignedMSB2 2 10 16 1 0 Small detector spectrum. 389 32 SD_SPECTRUM 1 1 UnsignedMSB2 2 11 16 1 0 Inner scintillator background spectrum. 421 32 IN_SPECTRUM 1 1 UnsignedMSB2 2 12 16 1 0 Outer scintillator background spectrum. 453 32 OUT_SPECTRUM 1 1 UnsignedMSB2 2 13 16 1 0 Neutron spectrum from the inner scintillator. 485 32 NEUTRON_SPECTRUM 1 1 UnsignedMSB2 2 14 60 1 0 Inner scintillator profile data. Time resolution is 1 second. 517 60 IN_PROFILE 1 1 UnsignedByte 1 15 240 1 0 Outer scintillator profile data. Time resolution is 0.25 seconds. 577 240 OUT_PROFILE 1 1 UnsignedByte 1 16 6 1 0 Data for the most recent command received. First byte is the code, second byte is the parameter, 3rd byte is the checksum, final three bytes are the receiving time. 817 6 CMD1 1 1 UnsignedByte 1 17 6 1 0 Data for the 2nd most recent command received. First byte is the code, second byte is the parameter, 3rd byte is the checksum, final three bytes are the receiving time. 823 6 CMD2 1 1 UnsignedByte 1 18 6 1 0 Data for the 3rd most recent command received. First byte is the code, second byte is the parameter, 3rd byte is the checksum, final three bytes are the receiving time. 829 6 CMD3 1 1 UnsignedByte 1 19 6 1 0 Data for the 4th most recent command received. First byte is the code, second byte is the parameter, 3rd byte is the checksum, final three bytes are the receiving time. 835 6 CMD4 1 1 UnsignedByte 1 20 6 1 0 Data for the 5th most recent command received. First byte is the code, second byte is the parameter, 3rd byte is the checksum, final three bytes are the receiving time. 841 6 CMD5 1 1 UnsignedByte 1 21 6 1 0 Data for the 6th most recent command received. First byte is the code, second byte is the parameter, 3rd byte is the checksum, final three bytes are the receiving time. 847 6 CMD6 1 1 UnsignedByte 1 hend_spectra_20250412.lbl 0 PDS3 PDS3 label Carriage-Return Line-Feed