While this may be feasible for one glacier, it is nearly impossible to measure a hundred glaciers this way. Satellite sensors such as those on Landsat 5 and Landsat 7 allow scientists to measure the entire rim of any glacier on an annual basis, cloud cover permitting. The satellites' images are then beamed back to the surface, where Hall and other researchers can examine them. Using satellites to watch glaciers Types of glaciers False color satellite image of the glaciers surrounding Mount McKinley, Alaska. Landsat, August 24, 1979.
Glaciers are blue, clean snow is white, vegetation is red and bare rock is brown.