HR: 0800h
AN: P21A-0201    [Abstracts]
TI: Terrain Roughness from MER Traverse Profiles at Gusev Crater and Meridiani Planum
AU: * Ehlmann, B L
EM: bethany.ehlmann@wustl.edu
AF: Department of Earth and Planetary Sciences, Washington University, Campus Box 1169 1 Brookings Drive, St. Louis, MO 63130
AU: Snider, N O
EM: snider@wunder.wustl.edu
AF: Department of Earth and Planetary Sciences, Washington University, Campus Box 1169 1 Brookings Drive, St. Louis, MO 63130
AU: Seelos, F P
EM: seelos@wunder.wustl.edu
AF: Department of Earth and Planetary Sciences, Washington University, Campus Box 1169 1 Brookings Drive, St. Louis, MO 63130
AU: Arvidson, R E
EM: arvidson@wunder.wustl.edu
AF: Department of Earth and Planetary Sciences, Washington University, Campus Box 1169 1 Brookings Drive, St. Louis, MO 63130
AB: During the traverses of the Mars Exploration Rovers Spirit and Opportunity over their respective landing sites, telemetry data were collected from the rover inertial measurement unit (IMU) and suspension system at 2-8 Hz. Joint angles in the rover's rocker-bogie suspension system, rover attitude, and rover reported position were used to calculate x-y-z coordinates of each of the six rover wheels. These data were used to create mm-scale topographic profiles along selected rover traverses. Terrain at Meridiani Planum is remarkably flat, consistent with predictions from orbital data. For example, the 140.9 m long sol 82 traverse shows a variation of 40.3 cm over the total traverse with a height standard deviation of only 3.2 cm over the first 55 m. In contrast, profiles from the Gusev crater landing site are rougher and characteristic of a surface with abundant rocks and hollows. The sol 45 and 50 traverses show the profile of Laguna Hollow, a ~20 m wide and half meter deep crater. At both landing sites, cm scale periodicity is evident in some segments of the traverse, suggesting the wavelength and amplitude of aeolian bedforms is being sensed and recorded by the rover wheels. Data are being analyzed to compute surface roughness statistics (RMS height, RMS deviation, and Hurst exponent) and evaluate azimuthal dependency of roughness. These statistics, when compared to those of analog terrestrial terrains, provide insight into the geomorphological processes shaping the martian surface in Gusev Crater and at Meridiani Planum. Further, along with stereo imaging from Pancam and Navcam, examination of topographic profiles allows ground truthing over multiple length scales terrain roughness estimates derived from radar scattering and MOLA pulse width.
DE: 5415 Erosion and weathering
DE: 5460 Physical properties of materials
DE: 5470 Surface materials and properties
DE: 5494 Instruments and techniques
DE: 6225 Mars
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting