urn:nasa:pds:mess_ns_derived:data_cdr:ns_cdr_spe2012144zzz_dat 1.0 1.10.1.0 Product_Observational 2018-10-17 1.0 PDS4 migrated product. 2012-05-23T00:00:07Z 2012-05-23T23:59:40Z 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 Neutron Spectrometer Instrument urn:nasa:pds:context:instrument:ns.mess is_instrument Mercury Planet urn:nasa:pds:context:target:planet.mercury data_to_target Mercury Orbit Year 2 1/246218673 1/246305046 ns_cdr_spectra ns_cdr_gen 1.0 ns_cdr_spe2012144zzz.dat 2015-10-31T07:00:49Z 0 1995 This table contains one set of calibrated spectra collected from the MESSENGER Neutron Spectrometer (NS) plus timing, spatial, and engineering information taken during the spectral collection period. A set is defined as all data with timestamps corresponding to a given day of year. 19 7 2959 mission_elapsed_time 1 1 UnsignedMSB4 4 second Time tag in seconds of the start of the associated reporting/accumulation period. utc_time 2 5 ASCII_String 19 UTC time at start of data collection. Format: YYYY-MM-DDTHH:MM:SS. utc_time_julday 3 24 IEEE754MSBDouble 8 UTC time at start of data collection given in Julian day. orbit_number 4 32 UnsignedMSB4 4 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 (see GEOMETRY/geominfo.txt). Orbit numbering does not start until MESSENGER performs the Mercury orbit insertion. Until that time the value for orbit number is 0. actual_accum 5 36 UnsignedMSB4 4 second Actual accumulation period in seconds for software counters and energy histograms. sc_altitude 6 40 IEEE754MSBSingle 4 km Spacecraft altitude above the subsatellite point on the target in units of km. sc_latitude 7 44 IEEE754MSBSingle 4 degree Target-centric latitude of the spacecraft subsatellite point in degrees. sc_longitude 8 48 IEEE754MSBSingle 4 degree Target-centric longitude of the spacecraft subsatellite point in degrees. vel_norm 9 52 IEEE754MSBSingle 4 km/s Magnitude of the spacecraft velocity as expressed in the nadir-fixed coordinate system in units of km/second. v_dot_x 10 56 IEEE754MSBSingle 4 unitless Velocity normalized dot product of the vector velocity and the spacecraft x-axis unit vector expressed as a unitless number from -1 to 1. v_dot_y 11 60 IEEE754MSBSingle 4 unitless Velocity normalized dot product of the vector velocity and the spacecraft y-axis unit vector expressed as a unitless number from -1 to 1. v_dot_z 12 64 IEEE754MSBSingle 4 unitless Velocity normalized dot product of the vector velocity and the spacecraft z-axis unit vector expressed as a unitless number from -1 to 1. nadir_angle 13 68 IEEE754MSBSingle 4 degree Spacecraft orientation angle of the spacecraft z-axis and the spacecraft-to-planet center vector in units of degrees. xaxis_angle 14 72 IEEE754MSBSingle 4 degree Spacecraft orientation angle of the spacecraft x-axis and the spacecraft-to-planet center vector in units of degrees. yaxis_angle 15 76 IEEE754MSBSingle 4 degree Spacecraft orientation angle of the spacecraft y-axis and the spacecraft-to-planet center vector in units of degrees. theta_angle 16 80 IEEE754MSBSingle 4 degree 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). phi_angle 17 84 IEEE754MSBSingle 4 degree 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. beta_angle 18 88 IEEE754MSBSingle 4 degree Angle of the normal of the spacecraft orbital plane with respect to Mercury-to-Sun vector in degrees. sun_distance 19 92 IEEE754MSBSingle 4 km Distance of the spacecraft to the Sun in units of km. 1 3 1 0 96 12 vel_vector 20 1 IEEE754MSBSingle 4 km/s Three element spacecraft velocity vector expressed in the nadir-fixed coordinate system with each component in units of km/second. 2 9 1 0 108 36 sc_to_nadir_rot 21 1 IEEE754MSBSingle 4 unitless Nine element rotation matrix that converts the spacecraft attitude from instrument-fixed coordinates to nadir-fixed coordinates. 3 64 1 0 144 256 lg1_spectra 22 1 IEEE754MSBSingle 4 counts/second LG1 singles spectra in counts per second. 4 64 1 0 400 256 lg2_spectra 23 1 IEEE754MSBSingle 4 counts/second LG2 singles spectra in counts per second. 5 64 1 0 656 256 bp_spectra 24 1 IEEE754MSBSingle 4 counts/second Borated plastic singles spectra in counts per second. 6 256 1 0 912 1024 tc_early_spectra 25 1 IEEE754MSBSingle 4 counts/second Borated plastic Time Correlated (TC) first interaction spectra from the early time window in counts per second. 7 256 1 0 1936 1024 tc_late_spectra 26 1 IEEE754MSBSingle 4 counts/second Borated plastic Time Correlated (TC) first interaction spectra from the late time window in counts per second. ns_cdr_spe2012144zzz.lbl 0 PDS3 Original PDS3 label Carriage-Return Line-Feed