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 spacecraft calibration data. Pulser Spectra are composed of the instrument derived spectra of three artificially produced pulses of energy as well as associated timing and spatial information. During the normal spectrum collection time voltage pulses of known amplitude, and a flag labeling them as pulsers, are sent to the GRS 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 detector and electronic components as functions of instrument temperatures, voltages, and other variables.

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).
SC_EV_TIME MSB_UNSIGNED_INTEGER 8
Spacecraft time at the middle of the pixel, in ticks.
CEB_TIME MSB_UNSIGNED_INTEGER 8 MILLISECOND
Clock count from the GRS Common Electronics Box at the beginning of the pixel.
UTC CHARACTER 23
SC_EV_TIME converted to UTC, stored as yyyy-mm-ddThh:mm:ss.sss.
GRS_PIXEL_NUMBER MSB_UNSIGNED_INTEGER 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.
GRS_ORBIT_NUMBER MSB_UNSIGNED_INTEGER 4
Sequential counter of orbits from GRS CEB boot.
ODY_ORBIT_NUMBER MSB_UNSIGNED_INTEGER 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.
BAD_CODE MSB_UNSIGNED_INTEGER 4
If non-zero, the data has been flagged bad. Definitions in bad_code.txt.
COUNTER MSB_UNSIGNED_INTEGER 1
The packet counter from the pulser packet, values from 0 to 15.
FIRST_CHAN MSB_UNSIGNED_INTEGER 2
Starting channel of first 500-channel wide spectrum.
MID_CHAN MSB_UNSIGNED_INTEGER 2
Starting channel of second 500-channel wide spectrum.
LAST_CHAN MSB_UNSIGNED_INTEGER 2
Starting channel of third 500-channel wide spectrum.
SPECTRUM MSB_UNSIGNED_INTEGER 1500
Pulser Spectrum.