Data Set Overview : The Mars Exploration Rover 2 (MER2) Radio Science (RS) data archive contains raw radio tracking data collected during the surface lifetime of the MER2 Rover. The data contain potentially valuable information on the rotation dynamics of Mars, extending the previous data available from the Viking and Mars Pathfinder landers. For more information on the investigations see [FOLKNERETAL1997A]. The raw data include two primary data types. Orbit Data Files (ODFs) contain measurements of the Doppler shift of the MER2 radio signal as measured by tracking stations of the NASA Deep Space Network. Ultra-High-Frequency Doppler Files (UHFD) contain measurements of the Doppler shift of the MER2 radio signal as measured by a counter on the Mars Odyssey orbiter. Parameters : The ODF contains the radio tracking information (range and Doppler) needed by spacecraft navigation teams and investigators interested in determining gravitational fields of bodies such as Mars. Each ODF is accompanied by a full PDS label which describes both the content and format of the associated file. ODF fields include: Narrowband spacecraft VLBI, Doppler mode (cycles) Narrowband spacecraft VLBI, phase mode (cycles) Narrowband quasar VLBI, Doppler mode (cycles) Narrowband quasar VLBI, phase mode (cycles) Wideband spacecraft VLBI (nanoseconds) Wideband quasar VLBI (nanoseconds) One-way Doppler (Hertz) Two-way Doppler (Hertz) Three-way Doppler (Hertz) One-way total count phase (cycles) Two-way total count phase (cycles) Three-way total count phase (cycles) PRA planetary operational discrete spectrum range (range units) SRA planetary operational discrete spectrum range (range units) Azimuth angle (degrees) Elevation angle (degrees) Hour angle (degrees) Declination angle (degrees) X angle (where +X is east) (degrees) Y angle (where +X is east) (degrees) X angle (where +X is south) (degrees) Y angle (where +X is south) (degrees) Processing : No processing has been done on the ODF UHFD files, Data : ODFs are stored in the ODF directory. File names are of the form yyddd_eee.DAT where yy is the two-digit year of the first data, ddd is the three-digit day-of-year of the first data point, and eee is the three-digit day-of-year of the last data point. Ancillary Data : Files in the CALIB Directory ---------------------------- The CALIB directory includes files with station calibrations for Earth troposphere and ionosphere effects. Each file is accompanied by a PDS label. Software : Software for parsing, reducing, and analyzing data such as these has been developed at several institutions. Because such software must usually operate at the bit-level and is written for a narrow range of platforms, it is not suitable for general distribution. No software is included with this archival data set.

Data Coverage and Quality : This archive includes all radio tracking data collected from MER2 beginning with landing on 2009-03-22 through 2010-02-24. Most of the data in the archive have not been evaluated for accuracy beyond preliminary screening.