Analysis of MOLA data for the Mars Exploration Rover landing sites

We have used Mars Orbiter Laser Altimeter (MOLA) data to demonstrate that selected landing sites meet the Mars Exploration Rover (MER) landing system topography and slope requirements at hectometer and kilometer scales. To provide a comprehensive analysis, we constrained slopes within each landing ellipse using four approaches: (1) measurements of local slopes at 1.2 km length scales using both an adirectional maximum gradient method and a higher-resolution bidirectional, along-track method, (2) predictions of 100 m slopes using self-affine statistics in conjunction with (3) calculations of both pulse width and slope corrected pulse width to constrain slopes at scales smaller than the MOLA spot size (<180 m), and (4) comparisons of simultaneously acquired MOLA data with Mars Orbiter Camera data to identify the geomorphologic features associated with variations in observed slopes, pulse width, and, for this analysis only, reflectivity. The results of the analysis indicate that the selected landing sites are consistent with the MER topography requirement of being below -1.3 km, as well as having slopes less than 5 degrees at length scales of 100 m and <2degrees at length scales of 1.2 km.