OBJECT = COLUMN NAME = J2000_ET COLUMN_NUMBER = 1 BYTES = 16 DATA_TYPE = ASCII_REAL START_BYTE = 1 UNIT = SECOND FORMAT = "F16.5" DESCRIPTION = "Ephemeris time converted from MESSENGER MET." END_OBJECT = COLUMN OBJECT = COLUMN NAME = JDAY COLUMN_NUMBER = 2 BYTES = 16 DATA_TYPE = ASCII_REAL START_BYTE = 17 FORMAT = "F16.5" DESCRIPTION = "Julian date at the start of the time period of interest. Julian date is defined as an integer count of days elapsed since noon, January 1, 4713 B.C. The value includes the fractional portion of the Julian day." END_OBJECT = COLUMN OBJECT = COLUMN NAME = MET COLUMN_NUMBER = 3 BYTES = 13 DATA_TYPE = ASCII_INTEGER START_BYTE = 33 UNIT = SECOND DESCRIPTION = "Mission elapsed time in seconds." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ACCUM_TIME COLUMN_NUMBER = 4 BYTES = 13 DATA_TYPE = ASCII_INTEGER START_BYTE = 46 UNIT = SECOND DESCRIPTION = "The time period over which the rates were accumulated." END_OBJECT = COLUMN OBJECT = COLUMN NAME = DEADTIME_FRAC COLUMN_NUMBER = 5 BYTES = 13 DATA_TYPE = ASCII_REAL START_BYTE = 59 FORMAT = "F13.5" DESCRIPTION = "The fraction of time for which the detector was insensitive to events due to electronics processing of prior events." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ORBIT_NUMBER COLUMN_NUMBER = 6 BYTES = 6 DATA_TYPE = ASCII_INTEGER START_BYTE = 72 DESCRIPTION = "Unique identifier for a given orbit of MESSENGER 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." END_OBJECT = COLUMN OBJECT = COLUMN NAME = START_BIN COLUMN_NUMBER = 7 BYTES = 6 DATA_TYPE = ASCII_INTEGER START_BYTE = 78 DESCRIPTION = "Starting bin for the Shield Count Rate measurements. Initially values may be zero due to detector electronics deadtime." END_OBJECT = COLUMN OBJECT = COLUMN NAME = NUMBER_OF_BINS COLUMN_NUMBER = 8 BYTES = 6 DATA_TYPE = ASCII_INTEGER START_BYTE = 84 DESCRIPTION = "Number of bins in the shield spectra." END_OBJECT = COLUMN OBJECT = COLUMN NAME = GRS_PRIORITY_LEVEL COLUMN_NUMBER = 9 BYTES = 6 DATA_TYPE = ASCII_INTEGER START_BYTE = 90 DESCRIPTION = "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." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BAD_DATA_FLAG COLUMN_NUMBER = 10 BYTES = 6 DATA_TYPE = ASCII_INTEGER START_BYTE = 96 DESCRIPTION = "Values of 1 indicate that the data quality is poor, for example increased backgrounds due to solar particle events, or that the detector was not operating nominally, for example the bias voltage was off. Values of 0 indicate that the data are clean and suited for analysis." END_OBJECT = COLUMN OBJECT = COLUMN NAME = TRIPLE COLUMN_NUMBER = 11 BYTES = 13 DATA_TYPE = ASCII_REAL START_BYTE = 102 UNIT = "COUNTS/SEC" FORMAT = "F13.5" DESCRIPTION = "Triple coincidence count rate in the MESSENGER Neutron Spectrometer. This value is a known proxy for the spacecraft-incident galactic cosmic ray flux." END_OBJECT = COLUMN OBJECT = COLUMN NAME = PREAMP_TEMP COLUMN_NUMBER = 12 BYTES = 13 DATA_TYPE = ASCII_REAL START_BYTE = 115 UNIT = DEGC FORMAT = "F13.5" DESCRIPTION = "Temperature of the pre-amplifier." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SHLD_CHRG_RSET_1SEC COLUMN_NUMBER = 13 BYTES = 13 DATA_TYPE = ASCII_REAL START_BYTE = 128 UNIT = COUNTS FORMAT = "F13.5" DESCRIPTION = "Hardware Shield charge reset 1-second total." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SHAPER_TEMP COLUMN_NUMBER = 14 BYTES = 13 DATA_TYPE = ASCII_REAL START_BYTE = 141 UNIT = DEGC FORMAT = "F13.5" DESCRIPTION = "Shaper Temperature." END_OBJECT = COLUMN OBJECT = COLUMN NAME = ALTITUDE COLUMN_NUMBER = 15 BYTES = 10 DATA_TYPE = ASCII_REAL START_BYTE = 154 UNIT = KM FORMAT = "F10.1" DESCRIPTION = "Spacecraft altitude above the subsatellite point on the target in units of km." END_OBJECT = COLUMN OBJECT = COLUMN NAME = LATITUDE COLUMN_NUMBER = 16 BYTES = 9 DATA_TYPE = ASCII_REAL START_BYTE = 164 UNIT = DEGREE FORMAT = "F9.3" DESCRIPTION = "Target-centric latitude of the spacecraft subsatellite point in degrees." END_OBJECT = COLUMN OBJECT = COLUMN NAME = LONGITUDE COLUMN_NUMBER = 17 BYTES = 9 DATA_TYPE = ASCII_REAL START_BYTE = 173 UNIT = DEGREE FORMAT = "F9.3" DESCRIPTION = "Target-centric longitude of the spacecraft subsatellite point in degrees." END_OBJECT = COLUMN OBJECT = COLUMN NAME = LOCAL_TIME COLUMN_NUMBER = 18 BYTES = 9 DATA_TYPE = ASCII_REAL START_BYTE = 182 FORMAT = "F9.3" DESCRIPTION = "Local time of the spacecraft subsatellite point in hours from 0 to 24." END_OBJECT = COLUMN OBJECT = COLUMN NAME = VELOCITY_VECTOR COLUMN_NUMBER = 19 BYTES = 27 DATA_TYPE = ASCII_REAL START_BYTE = 191 UNIT = "KM/S" ITEMS = 3 ITEM_BYTES = 9 FORMAT = "F9.3" DESCRIPTION = "Three element spacecraft velocity vector expressed in the nadir-fixed coordinate system with each component in units of km/second." END_OBJECT = COLUMN OBJECT = COLUMN NAME = VEL_NORM COLUMN_NUMBER = 20 BYTES = 9 DATA_TYPE = ASCII_REAL START_BYTE = 218 UNIT = "KM/S" FORMAT = "F9.3" DESCRIPTION = "Magnitude of the spacecraft velocity as expressed in the nadir-fixed coordinate system in units of km/second." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SC_TO_NADIR_ROT COLUMN_NUMBER = 21 BYTES = 81 DATA_TYPE = ASCII_REAL START_BYTE = 227 ITEMS = 9 ITEM_BYTES = 9 FORMAT = "F9.3" DESCRIPTION = "Nine element rotation matrix that converts the spacecraft attitude from instrument-fixed coordinates to nadir-fixed coordinates." END_OBJECT = COLUMN OBJECT = COLUMN NAME = VDOT_X COLUMN_NUMBER = 22 BYTES = 9 DATA_TYPE = ASCII_REAL START_BYTE = 308 FORMAT = "F9.3" DESCRIPTION = "Velocity normalized dot product of the vector velocity and the spacecraft x-axis unit vector expressed as a unitless number from -1 to 1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = VDOT_Y COLUMN_NUMBER = 23 BYTES = 9 DATA_TYPE = ASCII_REAL START_BYTE = 317 FORMAT = "F9.3" DESCRIPTION = "Velocity normalized dot product of the vector velocity and the spacecraft y-axis unit vector expressed as a unitless number from -1 to 1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = VDOT_Z COLUMN_NUMBER = 24 BYTES = 9 DATA_TYPE = ASCII_REAL START_BYTE = 326 FORMAT = "F9.3" DESCRIPTION = "Velocity normalized dot product of the vector velocity and the spacecraft z-axis unit vector expressed as a unitless number from -1 to 1." END_OBJECT = COLUMN OBJECT = COLUMN NAME = NADIR_ANGLE COLUMN_NUMBER = 25 BYTES = 9 DATA_TYPE = ASCII_REAL START_BYTE = 335 UNIT = DEGREE FORMAT = "F9.3" DESCRIPTION = "Spacecraft orientation angle of the spacecraft z-axis and the spacecraft-to-planet center vector in units of degrees." END_OBJECT = COLUMN OBJECT = COLUMN NAME = YAXIS_ANGLE COLUMN_NUMBER = 26 BYTES = 9 DATA_TYPE = ASCII_REAL START_BYTE = 344 UNIT = DEGREE FORMAT = "F9.3" DESCRIPTION = "Spacecraft orientation angle of the spacecraft y-axis and the spacecraft-to-planet center vector in units of degrees." END_OBJECT = COLUMN OBJECT = COLUMN NAME = XAXIS_ANGLE COLUMN_NUMBER = 27 BYTES = 9 DATA_TYPE = ASCII_REAL START_BYTE = 353 UNIT = DEGREE FORMAT = "F9.3" DESCRIPTION = "Spacecraft orientation angle of the spacecraft x-axis and the spacecraft-to-planet center vector in units of degrees." END_OBJECT = COLUMN OBJECT = COLUMN NAME = THETA_ANGLE COLUMN_NUMBER = 28 BYTES = 9 DATA_TYPE = ASCII_REAL START_BYTE = 362 UNIT = DEGREE FORMAT = "F9.3" DESCRIPTION = "Polar angle look direction (in a theta,phi spherical geometry) of the spacecraft in the spacecraft-fixed coordinate system. THETA_ANGLE = 0 degrees is when the spacecraft z-axis points in the same direction as the spacecraft-to-planet center vector (nadir pointing)." END_OBJECT = COLUMN OBJECT = COLUMN NAME = PHI_ANGLE COLUMN_NUMBER = 29 BYTES = 9 DATA_TYPE = ASCII_REAL START_BYTE = 371 UNIT = DEGREE FORMAT = "F9.3" DESCRIPTION = "Azimuthal angle look direction (in a theta,phi spherical geometry) of the spacecraft in the spacecraft-fixed coordinate system. PHI_ANGLE = 0 degrees is when the spacecraft x-axis points along the direction of travel." END_OBJECT = COLUMN OBJECT = COLUMN NAME = BETA_ANGLE COLUMN_NUMBER = 30 BYTES = 9 DATA_TYPE = ASCII_REAL START_BYTE = 380 UNIT = DEGREE FORMAT = "F9.3" DESCRIPTION = "Angle of the normal of the spacecraft orbital plane with respect to Mercury-to-Sun vector in degrees." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SUN_DISTANCE COLUMN_NUMBER = 31 BYTES = 13 DATA_TYPE = ASCII_REAL START_BYTE = 389 UNIT = KM FORMAT = "F13.2" DESCRIPTION = "Distance of the spacecraft to the Sun in units of km." END_OBJECT = COLUMN OBJECT = COLUMN NAME = SHIELD_COUNT_SPECTRA COLUMN_NUMBER = 32 BYTES = 98304 DATA_TYPE = ASCII_INTEGER START_BYTE = 402 UNIT = COUNTS ITEMS = 16384 ITEM_BYTES = 6 DESCRIPTION = "High-time-resolution counter of the total event rate in the shield detector. Counter operates at a 10ms cadence for the duration of the accumulation period, resulting in a series of measurements that populate the 16384 channel spectrum. When fewer than 16384 channels are required, the remainder are set to zero. When more than 16384 channels are required, the last channel represents the sum of all measurements made after the array is filled. For all cases, the first approximately fifty channels are zero due to signal processing deadtime in the GRS electronics." END_OBJECT = COLUMN