Derived HEND Data

Derived HEND data are composed of raw counts, a background component, background subtracted counts and the associated timing and spatial information. The five raw counts fields included in the DHDs consist of the cumulative counts of neutrons at the detector of interest over one collection interval. The collection interval is approximately 19.7 seconds, but may vary over the course of mapping. The five background count fields are derived from spatial data and count data collected during the cruise phase of the mission. The five background subtracted count fields are the background subtracted counts at the detector of interest over one collection interval. Timing and spatial data provided with the counts include 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.

Column Descriptions
Column Name Type Bytes Units
SC_RECV_TIME MSB_UNSIGNED_INTEGER 8
The time this packet was received by the spacecraft, in ticks (256 per second).
UTC CHARACTER 23
UTC time at the middle of pixel, stored as yyyy-mm-ddThh:mm:ss.sss.
SUN_ACTIVITY BOOLEAN 1
1(active sun during pixel interval); 0(no active sun during pixel interval)
AREOCENTRIC_LATITUDE IEEE_REAL 4 DEGREE
Latitude in Mars fixed coordinates at the middle of the pixel.
AREOCENTRIC_EAST_LONGITUDE IEEE_REAL 4 DEGREE
Longitude in Mars fixed coordinates at the middle of the pixel.
LS IEEE_REAL 4
Solar longitude (L-sub-s) at the middle of pixel.
PIXEL_DURATION IEEE_REAL 4 SECOND
Duration of pixel in seconds.
SD_BACKGROUND IEEE_REAL 4
Background counts for the Small Detector.
MD_BACKGROUND IEEE_REAL 4
Background counts for the Medium Detector.
LD_BACKGROUND IEEE_REAL 4
Background counts for the Large Detector.
SC_LOW_BACKGROUND IEEE_REAL 4
Background counts for the low channels of the Inner Scintillator.
SC_HIGH_BACKGROUND IEEE_REAL 4
Background counts for the high channels of the Inner Scintillator.
SD_RAW_COUNTS IEEE_REAL 4
Counts gathered in the Small Detector during the pixel interval.
MD_RAW_COUNTS IEEE_REAL 4
Counts gathered in the Medium Detector during the pixel interval.
LD_RAW_COUNTS IEEE_REAL 4
Counts gathered in the Large Detector during the pixel interval.
SC_LOW_RAW_COUNTS IEEE_REAL 4
Counts gathered in the low channels of the Inner Scintillator during the pixel interval.
SC_HIGH_RAW_COUNTS IEEE_REAL 4
Counts gathered in the high channels of the Inner Scintillator during the pixel interval.
SD_ADJUSTED_COUNTS IEEE_REAL 4
Counts gathered in the Small Detector during the pixel interval with background subtracted.
MD_ADJUSTED_COUNTS IEEE_REAL 4
Counts gathered in the Medium Detector during the pixel interval with background subtracted.
LD_ADJUSTED_COUNTS IEEE_REAL 4
Counts gathered in the Large Detector during the pixel interval with background subtracted.
SC_LOW_ADJUSTED_COUNTS IEEE_REAL 4
Counts gathered in the low channels of the Inner Scintillator during the pixel interval with background subtracted.
SC_HIGH_ADJUSTED_COUNTS IEEE_REAL 4
Counts gathered in the high channels of the Inner Scintillator during the pixel interval with background subtracted.