A program of delay-Doppler mapping of the Galillean satellites is underway by L. Harcke and colleagues at Stanford University. The surfaces of Europa, Ganymede and Callisto have been imaged in order to determine the surface properties and look for different radar properties of the various terrain types. These maps will be correlated with the Galileo images of the satellites.ˆà

This image is a SC radar albedo map of the western hemisphere of Callisto. An ambiguity exists between the northern and southern halves of the planet due to the range-Doppler imaging technique employed, thus the image appears symmetric about the equator. A projection effect causes the resolution cells to be long and thin nearer to the equator. Signal to noise ratio is strongest near the sub-Radar point in the center of the image, and decreases moving towards the poles and the limb. The feature marked with a red X is several standard deviations above the noise level. A study correlating this object with labeled features in the Galileo mission optical image archive is ongoing.