urn:nasa:pds:odyssey_grs_dnd:data_science_derived:dnd_20250412 1.0 1.19.0.0 Product_Observational 2025-12-15 1.0 Release 94 2025-04-12T00:00:18.151Z 2025-04-12T23:59:55.457Z 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 DERIVED_NEUTRON_DATA 1.0 EXTENDED MISSION 365794352957 365816465565 dnd_20250412.dat derived_neutron_data_data_table 2025-12-15T20:11:04 0 4323 The DND product contains normalized neutron counting rates for all four of the Neutron Spectrometer prisms, from which thermal and epithermal neutron count rates are determined. Thermal and epithermal count rates are included in the data set. Background-corrected and normalized fast counting data are also provided for the nadir-looking prism (Prism 1). The data is presented in a table format with one row of data for each NS collection interval within a 24 Earth hour period. The DND data can be used along with models and calibration procedures described in the literature [Feldman et al., 2003; Prettyman et al., 2004] to study the composition and structure of the surface and atmosphere of Mars on sub-seasonal time scales. 49 4 256 SC_RECV_TIME 1 1 UnsignedMSB8 8 The time this packet was received by the spacecraft, in ticks (256 per second). CEB_TIME 2 9 UnsignedMSB8 8 Clock count from the GRS Common Electronics Box at the beginning of the pixel. UTC 3 17 ASCII_String 23 Time at the middle of the collection interval converted to UTC, stored as yyyy-mm-ddThh:mm:ss.sss. GRS_PIXEL_NUMBER 4 40 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 5 44 UnsignedMSB4 4 Sequential counter of orbits from GRS CEB boot. 0 ODY_ORBIT_NUMBER 6 48 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 AREOCENTRIC_LATITUDE 7 52 IEEE754MSBSingle 4 degrees Sub spacecraft latitude in Mars fixed coordinates at the middle of the collection interval. AREOCENTRIC_EAST_LONGITUDE 8 56 IEEE754MSBSingle 4 degrees Sub spacecraft longitude in Mars fixed coordinates at the middle of the collection interval. Longitude increases towards the East. ALTITUDE 9 60 IEEE754MSBSingle 4 km Areocentric altitude of the sub-spacecraft point in Mars-fixed rotating frame at the middle of the collection interval. 1 3 1 0 The geometric position (x,y,z) of the spacecraft with respect to Mars in the 'MARSIAU' IAU2000 reference system inertial frame at the input epoch 'et' at the middle of the pixel. 64 12 SCPOS_INERT 1 1 IEEE754MSBSingle 4 km 2 3 1 0 The geometric velocity (x,y,z) of the spacecraft with respect to Mars in the 'MARSIAU' IAU2000 reference system inertial frame at the input epoch 'et' at the middle of the pixel. 76 12 SCVEL_INERT 1 1 IEEE754MSBSingle 4 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 collection interval. If no spacecraft orientation data was available from the loaded CK files for the request time, then all elements of are set to zero. 88 12 MARSPOS_INSTR 1 1 IEEE754MSBSingle 4 km 4 3 1 0 Contains the inertial spacecraft velocity direction (x,y,z) rotated to the instrument frame at the middle of the collection interval. If no spacecraft orientation data was available for the request time, then all elements are set to zero. 100 12 MARSVEL_INSTR 1 1 IEEE754MSBSingle 4 km/s DAY_INDEX 10 112 UnsignedMSB2 2 Day of Martian year. LOCAL_HOUR 11 114 UnsignedMSB2 2 Local Sun hour at the sub-spacecraft point. LOCAL_MINUTE 12 116 UnsignedMSB2 2 Local Sun minute at the sub-spacecraft point. PIXEL_DURATION 13 118 IEEE754MSBSingle 4 s Length of the collection interval in seconds. POWER_SUPPLY 14 122 UnsignedMSB2 2 Which power supply is being used, 1 or 2. SWAP_FLAG 15 124 UnsignedMSB2 2 The state of the prompt/delayed swap flag. POWER_LEVEL 16 126 UnsignedMSB2 2 The power level of the power supply in use during the collection interval, 1 being highest power and 7 being lowest power. DIRECTION 17 128 UnsignedByte 1 Direction of spacecraft travel N(1) or S(0). LIVETIME 18 129 IEEE754MSBSingle 4 s In seconds, duration - deadtime, where deadtime = dead_cnt * .000512 sec. DEADTIME_PERCENT 19 133 IEEE754MSBSingle 4 Deadtime / duration. OVERLOAD_RATE 20 137 IEEE754MSBSingle 4 The OVERLOAD_RATE gives an estimate of the flux of charged particles that deposit energies greater than about 2.6 MeV. The OVERLOAD_RATE is determined by dividing the EDR GCR_CNT field by 110 cm2, which is the average projected area of the spectrometer, and by the collection interval duration (DND PIXEL_DURATION field). The units are centimeters squared per second. Note that the GCR_CNT field gives the number of overload events during a collection interval, corresponding to events that produce greater than 2.6 MeV equivalent light output. While these events can be caused by gamma rays and neutrons, most are associated with energetic particles. When the OVERLOAD_RATE is lowest, overload events are dominated by galactic cosmic rays, in which case the OVERLOAD_RATE gives an estimate of the galactic cosmic ray flux. The OVERLOAD_RATE is primarily used to identify periods of high count rate, which corresponding to energetic particle events. Such events are filtered from the DND data set by the processing algorithms. HVPS_MNTR_2 21 141 IEEE754MSBSingle 4 volts The value of the High Voltage Power Supply Monitor 2 at the mid point of the collection interval that has been smoothed with a Gaussian weighted smoothing algorithm over 30 HVPS_MNTR_2 measurements and interpolated to the time at the middle of the NS collection interval from the HVPS_MNTR_2 engineering measurement that happens just before the NS collection interval and the one just after the NS collection interval. LAT_1 22 145 IEEE754MSBSingle 4 degrees Latitude in degrees to be associated with CAT1, Prism 1 count rate and error LON_1 23 149 IEEE754MSBSingle 4 degrees Longitude in degrees to be associated with CAT1, Prism 1 count rate and error LAT_4_5 24 153 IEEE754MSBSingle 4 degrees Latitude in degrees to be associated with the thermal count rate and error LON_4_5 25 157 IEEE754MSBSingle 4 degrees Longitude in degrees to be associated with the thermal count rate and error CAT1_PRISM1_PEAK_AREA 26 161 IEEE754MSBSingle 4 The counting rate given by the area in the 10B(n,alpha)7Li reaction peak above background registered by prism 1, in units of s^-1. The counting rate as measured is normalized by the ratio of the average Cat1 Prism1 counting rate averaged over all transits between +30 degrees and -30 degrees latitude measured within +0.5 and -0.5 days of the current data point. This counting rate is also the epithermal neutron counting rate. CAT1_PRISM1_ERROR 27 165 IEEE754MSBSingle 4 The 1-sigma statistical error of the CAT1_PRISM1_PEAK_AREA (counts/s). CAT1_PRISM2_PEAK_AREA 28 169 IEEE754MSBSingle 4 The counting rate given by the area in the 10B(n,alpha)7Li reaction peak above background registered by prism 2, in units of s^-1. The counting rate as measured is normalized by the ratio of the average Cat1 Prism2 counting rate averaged over all transits between +30 degrees and -30 degrees latitude measured within +0.5 and -0.5 days of the current data point. CAT1_PRISM2_ERROR 29 173 IEEE754MSBSingle 4 The 1-sigma statistical error of the CAT1_PRISM2_PEAK_AREA (counts/s). CAT1_PRISM3_PEAK_AREA 30 177 IEEE754MSBSingle 4 The counting rate given by the area in the 10B(n,alpha)7Li reaction peak above background registered by prism 3, in units of s^-1. The counting rate as measured is normalized by the ratio of the average Cat1 Prism3 counting rate averaged over all transits between +30 degrees and -30 degrees latitude measured within +0.5 and -0.5 days of the current data point. CAT1_PRISM3_ERROR 31 181 IEEE754MSBSingle 4 The 1-sigma statistical error of the CAT1_PRISM3_PEAK_AREA (counts/s). CAT1_PRISM4_PEAK_AREA 32 185 IEEE754MSBSingle 4 The counting rate given by the area in the 10B(n,alpha)7Li reaction peak above background registered by prism 4, in units of s^-1. The counting rate as measured is normalized by the ratio of the average Cat1 Prism4 counting rate averaged over all transits between +30 degrees and -30 degrees latitude measured within +0.5 and -0.5 days of the current data point. CAT1_PRISM4_ERROR 33 189 IEEE754MSBSingle 4 The 1-sigma statistical error of the CAT1_PRISM4_PEAK_AREA (counts/s). CAT2_PRISM1_FAST_SUM 34 193 IEEE754MSBSingle 4 The sum of the counting rate in the lowest two channels of the [(early-time) - (late time)] fast-neutron histograms, in units of s^-1. The counting rate as measured is normalized by the ratio of the average CAT2_PRISM1_FAST_SUM counting rate averaged over all transits between +30 degrees and -30 degrees latitude measured within +0.5 and -0.5 days of the current data point. CAT2_PRISM1_ERROR 35 197 IEEE754MSBSingle 4 The 1-sigma statistical error of the CAT2_PRISM1_FAST_SUM (counts/s). THERMAL_COUNT_RATE 36 201 IEEE754MSBSingle 4 The difference between CAT1_PRISM2_Peak_Area and CAT1_PRISM4_Peak_Area, in units of s^-1. The counting rate as measured is normalized by the ratio of the Thermal Count Rate averaged over all transits between +30 degrees and -30 degrees latitude measured within +0.5 and -0.5 days of the current data point. THERMAL_ERROR 37 205 IEEE754MSBSingle 4 The 1-sigma statistical error of the THERMAL_COUNT_RATE (counts/s) CAT1_PRISM1_NORM_SLOPE 38 209 IEEE754MSBSingle 4 The slope parameter for the bellyband normalization for the CAT1_PRISM1_PEAK_AREA. CAT1_PRISM1_NORM_OFFSET 39 213 IEEE754MSBSingle 4 The offset parameter for the bellyband normalization for the CAT1_PRISM1_PEAK_AREA. CAT1_PRISM2_NORM_SLOPE 40 217 IEEE754MSBSingle 4 The slope parameter for the bellyband normalization for the CAT1_PRISM2_PEAK_AREA. CAT1_PRISM2_NORM_OFFSET 41 221 IEEE754MSBSingle 4 The offset parameter for the bellyband normalization for the CAT1_PRISM2_PEAK_AREA. CAT1_PRISM3_NORM_SLOPE 42 225 IEEE754MSBSingle 4 The slope parameter for the bellyband normalization for the CAT1_PRISM3_PEAK_AREA. CAT1_PRISM3_NORM_OFFSET 43 229 IEEE754MSBSingle 4 The offset parameter for the bellyband normalization for the CAT1_PRISM3_PEAK_AREA. CAT1_PRISM4_NORM_SLOPE 44 233 IEEE754MSBSingle 4 The slope parameter for the bellyband normalization for the CAT1_PRISM4_PEAK_AREA. CAT1_PRISM4_NORM_OFFSET 45 237 IEEE754MSBSingle 4 The offset parameter for the bellyband normalization for the CAT1_PRISM4_PEAK_AREA. CAT2_PRISM1_NORM_SLOPE 46 241 IEEE754MSBSingle 4 The slope parameter for the bellyband normalization for the CAT2_PRISM1_FAST_SUM. CAT2_PRISM1_NORM_OFFSET 47 245 IEEE754MSBSingle 4 The offset parameter for the bellyband normalization for the CAT2_PRISM1_FAST_SUM. CF_ATM_EPI 48 249 IEEE754MSBSingle 4 Correction factor for atmospheric mass for epithermal neutrons. CF_ATM_FAST 49 253 IEEE754MSBSingle 4 Correction factor for atmospheric mass for fast neutrons. dnd_20250412.lbl 0 PDS3 PDS3 label Carriage-Return Line-Feed