This is an RMS form of TOTAL VERTICAL ROUGHNESS as measured by fully slope-corrected MOLA optical pulse width, filtered to remove instrument effects etc. It is provided in meters as an absolute measure of the RMS residual roughness of 160m patches of Mars, after an attempt to model out the impact of local tilts. For more info, please see Garvin et al. (1999) GRL paper on this subject. We evaluated this form of data using our Shuttle Laser Altimeter (SLA) experiment for terrestrial deserts and its reproducible and robust. We are still working on a global assessment for which time variable effects are fully quantified, but this should be adequate for the trends...

Note that the global RMS Vertical Roughness from MOLA is about 1.6 m RMS with a large variance. Anything below about 1 m RMS is very smooth, while areas falling in the 1-1.7m RMS zone are smooth-moderate, those from 1.7-2.5 m RMS are moderate, and those in the 2.6-4 m RMS are rough. Areas with values above 4 m RMS are very rough and likely to be bouldery or SPINOSE at 10's of meter scales (like cockpit terrain).

I have NOT published this yet but have a draft paper ready for review by the entire MOLA Science Team.

THANKS

jim

Dr. Jim Garvin
Mars Exploration Program Scientist
NASA HQ
202-358-1798

Notes on Map Creation

The data was converted to a colorized map by first "clamping" all values in the data to the range 0 to 5, in order to optimize the color map for values that are most important for landing site criteria. A color spectrum was then applied to the resultant grayscale map using Photoshop. The composite version of the map contains a MOLA terrain shaded relief map underlying the data.