The images in this directory with names "*_crop.tif" were derived from Brian's
 descent sequence by (1) cropping to eliminate the dark regions at the corners,
 (2) averaging over red, green, and blue channels to produce a grayscale 
representation, and (3) normalizing the pixel values by dividing each grayscale
image by 255. The "*_crop.tif" images were then processed to yield relative 
hazard maps, named "*_hmap.tif". The hypothetical lander was assumed to 
have a radius of 2m, a camera whose pixels subtended an angle of 0.00175 radians 
along each dimention, and a minimum significant obstacle size of 30cm. Assumed 
altitudes and landing precisions are given below.

image		altitude		landing stdv	
P0000105		2500m		100m
P0000104		1500m		60m
P0000103		750m		30m
P0000102		500m		20m
P0000101		300m		12m
P0000100		50m		2m

The hazard maps represent RELATIVE hazard. That is, they reflect the safest (blue)
 and most hazardous (red) targets for landing within the field of view, but say nothing 
about the absolute hazard associated with selecting a given point for landing.