urn:nasa:pds:mess_grs_derived:data_cdr:grs_cs22012173zzz_dat 1.0 1.10.1.0 Product_Observational 2018-07-03 1.0 PDS4 migrated product. 2012-06-21T00:00:02.912Z 2012-06-21T23:59:10.913Z MESSENGER Mission urn:nasa:pds:context:investigation:mission.messenger data_to_investigation MESSENGER Spacecraft urn:nasa:pds:context:instrument_host:spacecraft.mess is_instrument_host Gamma Ray Spectrometer Instrument urn:nasa:pds:context:instrument:grs.mess is_instrument Mercury Planet urn:nasa:pds:context:target:planet.mercury data_to_target Mercury Orbit Year 2 1/248724268 1/248810616 grs_cdr_gen 1.0 shield grs_cs22012173zzz.dat 2015-09-21T15:54:58Z 0 318 This table contains one set of Shield (SHI) spectra collected from the high purity Germanium (HPGe) detector plus spatial and temporal information and relevant engineering and counter and pulser data from the time the spectra was taken. A set is defined as all data with time stamps corresponding to a given day of year. 41 4 1245 met 1 1 UnsignedMSB4 4 Mission elapsed time, in seconds, corresponding to the start of the accumulation period for the spectra. accum_time 2 5 UnsignedMSB4 4 Accumulation time, in seconds, of the Shield detector. midpoint_met 3 9 UnsignedMSB4 4 The mission elapsed time at the midpoint of the shield Raw observation. Defined as: MET at the start of the observation + (ACCUM_TIME / 2). orbit_number 4 13 UnsignedMSB2 2 Orbit number is a unique identifier for a given orbit of the MESSENGER spacecraft around Mercury. Orbit number is defined as starting at apoherm and is calculated using the MET value and the appropriate SPICE kernels. Orbit numbering does not start until MESSENGER performs the Mercury orbit insertion. Until that time the value for orbit Number is 0. initial_energy 5 15 IEEE754MSBSingle 4 The energy of the middle of the first bin of the FAST and THERMAL NEURTON HPGE spectra. grs_priority_level 6 19 UnsignedMSB2 2 Indicates the type of priority assigned to the science packet. The priority level is tied to the ApID of the packet. Priority level varies from 0-3, 0 being highest and 3 being lowest priority. bad_data_flag 7 21 UnsignedMSB2 2 Intended for use as a bit-string bad data flag to indicate specific problems associated with the data. Values are expected to be assigned to specific bits as problems are identified during the course of the mission. Bit 1 - The high voltage is not on, is being ramped or has not been stable long enough. Bit 2 - Indicates a change in the analog pulse processing system gain setting. Bit 3 - Indicates a spectrum where the temperatures used for correction have fluctuated by greater than 5 percent from previous readings. Bit 4 - Indicates gamma spectra collected during a solar particle event. These spectra should not be combined with spectra collected under normal solar conditions. Bit 5 - Pulser data is not combined with the spectrum. Bit 6 - Indicates gamma spectra collected during a solar flare event. These spectra should not be combined with spectra collected under normal solar conditions. Bit 7 - Indicates gamma spectra collected during periods of decreased GS detector spectral resolution. These spectra should not be combined with spectra collected under 'normal' detector conditions. Bit 8 - Not all data channels were received on the ground. Bit 9 - Indicates a unique problem with single spectrum. Bit 10 - The high voltage has not been stable long enough. Bit 11 - This data was taken during a time when the spectra were particularly noisy. Many channels have far too many counts, especially the lower channels. num_buffered_events 8 23 UnsignedMSB2 2 The number of bytes in the raw event buffer. The number of events in the raw event buffer is (Raw Bytes-16)/8. The number of raw events in the buffer will range from 0 to 126. Note there must be at least one event in the buffer before the Event Buffer Header will be generated. num_raw_events 9 25 UnsignedMSB2 2 This value contains a count of the total number of raw events detected and is not limited by the length of the buffer. This counter will rollover if the count exceeds 65535. zct_thermal_min 10 27 UnsignedMSB2 2 Window parameter that sets the minimum acceptable time difference between shield and HpGe triggers for an event to be considered a thermal neutron. Units are 100 ns/tick. Parameter is inclusive, i.e., values equal to this parameter are accepted. zct_therm_max 11 29 UnsignedMSB2 2 Window parameter that sets the maximum acceptable time difference between shield and HpGe triggers for an event to be considered a thermal neutron. Units are 100 ns/tick. Parameter is exclusive, i.e., values equal to this parameter are rejected zct_fast_min 12 31 UnsignedMSB2 2 Window parameter that sets the minimum acceptable time difference between shield and HpGe triggers for an event to be considered a fast neutron. Units are 100 ns/tick. Parameter is inclusive, i.e., values equal to this parameter are accepted. zct_fast_max 13 33 UnsignedMSB2 2 Window parameter that sets the maximum time difference between shield and HpGe triggers for an event to be considered a fast neutron. Units are 100 ns/tick. Parameter is exclusive, i.e., values equal to this parameter are rejected. shield_shifts_raw 14 35 UnsignedMSB2 2 The number of right shifts (divide by 2s) that are applied to raw shield pulse heights prior to binning in the Shield All Events spectrum. Possible values are 2 or 3. A value of two effectively increases the binning resolution but decreases the dynamic range (maximum binned energy). shield_shifts_neutron 15 37 UnsignedMSB2 2 The number of right shifts (divide by 2s) that are applied to raw shield pulse heights prior to binning in either the Shield Thermal Events spectrum or the Shield Fast Events spectrum. Possible values are 2 or 3. A value of two effectively increases the binning resolution but decreases the dynamic range (maximum binned energy). 1 64 1 0 39 256 hpge_thermal 1 1 IEEE754MSBSingle 4 Thermal Neutron spectrum about the 478-keV line, normalized to 0.60 keV energy bins. 2 64 1 0 295 256 hpge_fast 1 1 IEEE754MSBSingle 4 Fast Neutron spectrum about the 478-keV line, normalized to 0.60 keV energy bins. 3 128 1 0 551 256 shield_thermal 1 1 UnsignedMSB2 2 Raw Thermal Neutron spectrum about the 478-keV line. 4 128 1 0 807 256 shield_fast 1 1 UnsignedMSB2 2 Raw Fast Neutron spectrum about the 478-keV line. utc_midpoint_met 16 1063 ASCII_String 23 midpoint_met converted to UTC, stored as yyyy-mm-ddThh:mm:ss.sss. mercury_centric_latitude 17 1086 IEEE754MSBDouble 8 Sub spacecraft latitude in Mercury fixed coordinates at the middle of the collection interval. mercury_centric_longitude 18 1094 IEEE754MSBDouble 8 Sub spacecraft longitude in Mercury fixed coordinates at the middle of the collection interval. Longitude increases towards the East. instr_boresight_mercury_x 19 1102 IEEE754MSBDouble 8 Sub instrument boresight (x component) in Mercury fixed coordinates at the middle of the collection interval. instr_boresight_mercury_y 20 1110 IEEE754MSBDouble 8 Sub instrument boresight (y component) in Mercury fixed coordinates at the middle of the collection interval. instr_boresight_mercury_z 21 1118 IEEE754MSBDouble 8 Sub instrument boresight (z component) in Mercury fixed coordinates at the middle of the collection interval. scalt 22 1126 IEEE754MSBDouble 8 Mercury centric altitude of the sub-spacecraft point in Mercury-fixed rotating frame at the middle of the collection interval. delta_angle 23 1134 IEEE754MSBDouble 8 Difference between instrument +y direction and true north at the middle of the collection interval. mercury_sol 24 1142 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 Mercury'. local_hour 25 1150 UnsignedByte 1 Local Sun hour at the sub-spacecraft point. local_minute 26 1151 UnsignedByte 1 Local Sun minute at the sub-spacecraft point. pointing 27 1152 UnsignedByte 1 True if pointing data was available. intersecting 28 1153 UnsignedByte 1 True if the pointing vector intersects Mercury. nadir_angle 29 1154 IEEE754MSBDouble 8 Spacecraft attitude during orbits and flybys is defined by two additional coordinate systems, the GRS LVLH (Local Vertical Local Horizontal) frame and the spacecraft fixed frame, and by the rotation of the spacecraft frame with respect to the GRS LVLH frame. In the GRS LVLH frame, the Z axis is aligned with the vector from the spacecraft to the planet center (the nadir direction), the Y axis is the negative of the cross product of the position and velocity vectors, and the X axis points in the instantaneous direction of motion, completing a right-handed coordinate system. The Z axis is along the viewing direction of the instrument deck inside the adapter ring and of the GRS just outside the adapter ring, the Y axis is directed from the spacecraft along the magnetometer boom, and the X-axis is parallel to the solar panel booms, forming a right-handed coordinate system. The spacecraft attitude is specified by the rotation of the spacecraft fixed frame Z axis in the GRS LVLH frame and a twist angle about the Z axis. The Z axis rotation is given by a nadir angle and an azimuth angle, where the nadir angle is 0 degrees when the spacecraft Z axis points along the + Z LVLH axis and 180 degrees when it points along -Z in the LVLH frame, and the LVLH azimuth angle is measured counterclockwise about the Z LVLH axis from the X LVLH axis. The twist angle is measured positive about the +Z spacecraft axis. See section 5.4.2 in the GRS_CDR_SIS for further details. azimuth 30 1162 IEEE754MSBDouble 8 Spacecraft attitude during orbits and flybys is defined by two additional coordinate systems, the GRS LVLH (Local Vertical Local Horizontal) frame and the spacecraft fixed frame, and by the rotation of the spacecraft frame with respect to the GRS LVLH frame. In the GRS LVLH frame, the Z axis is aligned with the vector from the spacecraft to the planet center (the nadir direction), the Y axis is the negative of the cross product of the position and velocity vectors, and the X axis points in the instantaneous direction of motion, completing a right-handed coordinate system. The Z axis is along the viewing direction of the instrument deck inside the adapter ring and of the GRS just outside the adapter ring, the Y axis is directed from the spacecraft along the magnetometer boom, and the X-axis is parallel to the solar panel booms, forming a right-handed coordinate system. The spacecraft attitude is specified by the rotation of the spacecraft fixed frame Z axis in the GRS LVLH frame and a twist angle about the Z axis. The Z axis rotation is given by a nadir angle and an azimuth angle, where the nadir angle is 0 degrees when the spacecraft Z axis points along the + Z LVLH axis and 180 degrees when it points along -Z in the LVLH frame, and the LVLH azimuth angle is measured counterclockwise about the Z LVLH axis from the X LVLH axis. The twist angle is measured positive about the +Z spacecraft axis. See section 5.4.2 in the GRS_CDR_SIS for further details. twist_angle 31 1170 IEEE754MSBDouble 8 Spacecraft attitude during orbits and flybys is defined by two additional coordinate systems, the GRS LVLH (Local Vertical Local Horizontal) frame and the spacecraft fixed frame, and by the rotation of the spacecraft frame with respect to the GRS LVLH frame. In the GRS LVLH frame, the Z axis is aligned with the vector from the spacecraft to the planet center (the nadir direction), the Y axis is the negative of the cross product of the position and velocity vectors, and the X axis points in the instantaneous direction of motion, completing a right-handed coordinate system. The Z axis is along the viewing direction of the instrument deck inside the adapter ring and of the GRS just outside the adapter ring, the Y axis is directed from the spacecraft along the magnetometer boom, and the X-axis is parallel to the solar panel booms, forming a right-handed coordinate system. The spacecraft attitude is specified by the rotation of the spacecraft fixed frame Z axis in the GRS LVLH frame and a twist angle about the Z axis. The Z axis rotation is given by a nadir angle and an azimuth angle, where the nadir angle is 0 degrees when the spacecraft Z axis points along the + Z LVLH axis and 180 degrees when it points along -Z in the LVLH frame, and the LVLH azimuth angle is measured counterclockwise about the Z LVLH axis from the X LVLH axis. The twist angle is measured positive about the +Z spacecraft axis. See section 5.4.2 in the GRS_CDR_SIS for further details. ad_temp 32 1178 IEEE754MSBDouble 8 Channel 06, AD Temperature, smoothed and interpolated to the center of the collection interval. hvps_temp 33 1186 IEEE754MSBDouble 8 HVPS Temperature, smoothed and interpolated to the center of the collection interval. hvps_volt 34 1194 IEEE754MSBDouble 8 HVPS Voltage, smoothed and interpolated to the center of the collection interval. hvps_ref_volt 35 1202 IEEE754MSBDouble 8 HVPS Reference Voltage, smoothed and interpolated to the center of the collection interval. preamp_temp 36 1210 IEEE754MSBDouble 8 Channel 04, Pre Amp Temperature, smoothed and interpolated to the center of the collection interval. shaper_temp 37 1218 IEEE754MSBDouble 8 Channel 05, Shaper Temperature, smoothed and interpolated to the center of the collection interval. hv_monitor 38 1226 IEEE754MSBDouble 8 Channel 07, HV Monitor, smoothed and interpolated to the center of the collection interval. hpge_raw_events 39 1234 UnsignedMSB4 4 Counter of HPGe Raw events. shield_raw_events 40 1238 UnsignedMSB4 4 Counter for SHIELD raw events. accumulated_dead_time 41 1242 UnsignedMSB4 4 Counter for accumulated dead time. grs_cs22012173zzz.lbl 0 PDS3 Original PDS3 label Carriage-Return Line-Feed