urn:nasa:pds:mess_rs_derived:data:mess_rs_occ_v04 1.0 1.11.0.0 Product_Observational 2018-07-02 1.0 PDS4 migrated product. 2008-01-14T19:10:29.700Z 2015-04-26T15:24:09.850Z 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 radio science subsystem Instrument urn:nasa:pds:context:instrument:rss.mess is_instrument Mercury Planet urn:nasa:pds:context:target:planet.mercury data_to_target OCC mess_rs_occ_v04.csv 2016-02-24T00:00:00

0 302 7-Bit ASCII Text The first record in the file contains a list of the column headings for the data in the following records. This header record is comma-delimited.

302 PDS DSV 1 This file contains a summary of MESSENGER radio occultation measurements of the radius of Mercury. 636 Carriage-Return Line-Feed Comma 17 0 rsr_file 1 ASCII_String 31 The name of the Radio Science Receiver file that contains the raw data for this occultation. trajectory_file(spk) 2 ASCII_String 36 Spacecraft mission ephemeris file name. ingress/egress 3 ASCII_String 1 Occultation event, ingress (I) or egress (E). occultation_time 4 ASCII_Date_Time_DOY 21 The time, in UTC, of geometric occultation as observed at the DSN station. This is the time when RF power is one quarter (-6dB) of the unocculted power. orbit_number 5 ASCII_Integer 5 Spacecraft orbit number for this occultation. Orbit one begins at the first apoapsis following the orbit-insertion maneuver. Orbit zero (0) indicates a flyby occultation. direction_of_rf_path 6 ASCII_Real 8 degree The angle between the local meridian and the direction of Earth at the occultation point, measured positive from local north toward local east. The angle or bearing indicates the direction of signal propagation. A RF signal traveling from due west toward due east as it grazed the surface would have a Direction_of_RF_Path of 90 degrees. perpendicular_speed 7 ASCII_Real 5 km/s The component of the apparent velocity of MESSENGER with respect to Mercury's limb that is perpendicular to both the limb and the line of sight to Earth. When multiplied by the uncertainty in time, perpendicular_speed provides the time-based uncertainty in the radius measurement derived from the occultation time. tangent_latitude 8 ASCII_Real 7 degree At the time of geometric occultation, this is the latitude that the RF path would graze the surface of a smooth sphere centered at Mercury's center of mass. tangent_longitude 9 ASCII_Real 8 degree At the time of geometric occultation, this is the longitude that the RF path would graze the surface of a smooth sphere centered at Mercury's center of mass. raw_measured_radius 10 ASCII_Real 8 km At the time of geometric occultation, this is the minimum distance between Mercury's center of mass and the RF path between MESSENGER and the DSN antenna in contact with MESSENGER. Calculations include light-time effects. time_uncertainty 11 ASCII_Real 5 second The uncertainty in the time of geometric occultation. time_res 12 ASCII_Real 5 second The time step of the RF power data used to fit to the diffraction pattern. decay_scale 13 ASCII_Real 5 second The scale length of the diffraction pattern, converted to seconds based on the velocities and geometry of MESSENGER, Mercury, and the Earth. pc/no 14 ASCII_Real 6 dB*Hz Downlink received carrier power (Watts) of the unocculted transmissions divided by the noise power spectral density (Watts/Hz). algorithm 15 ASCII_Integer 1 The integer identifies the algorithm used to extract the carrier power from the RSR data: 0= Fast Fourier Transform (FFT); 1= Software Phase Locked Loop (PLL); 2= Overlapping FFT. s/c-to-limb_distance 16 ASCII_Real 11 km At the time of occultation, the distance between MESSENGER and the smooth-sphere occultation point at Mercury. limb-to-dsn_distance 17 ASCII_Real 11 km At the time of occultation, the distance between the DSN station and the smooth-sphere occultation point at Mercury. mess_rs_occ_v04.lbl 0 PDS3 Original PDS3 label Carriage-Return Line-Feed