Chryse region, Viking Mars 1975 landing site 3, semicontrolled mosaic

This semicontrolled mosaic is made with computer enhanced Mariner 9 pictures, transformed to a Mercator projection. Frames were individually scaled for a best fit to the Transverse Mercator projection. Computer processing was performed by the Image Processing Laboratory (IPL) of the Jet Propulsion Laboratory (JPL), California Institute of Technology. Processing included contrast enhancement and high-pass filtering which accentuates topographic features while subduing albedo variations. Photographic reproductions of the images were generated from the IPL digital magnetic tapes and mosaicked by the U.S. Geological Survey.

Horizontal placement of pictures is controlled by Mariner 9 tracking data, and may differ from the newly defined martian coordinate system by as much as 60 km.