Ground-based observation of the deviation of artificial satellite trajectories from a reference path is the classical means for determining the parameters of the global geopotential. However, for the short wavelengths (<10¿), tracking coverage from ground stations of sufficient density is impossible to obtain. But one or more satellites can observe another satellite and obtain the needed global data coverage. In this paper we present the results of error analyses of possible satellite-to-satellite tracking missions to determine the geopotential at a resolution of 1¿¿1¿. To achieve an accuracy of a few milligals (1 mGal=10-3 cm/s2) at this resolution requires a satellite altitude at or near 150 km and measurement of intersatellite speed to 10-6 m/s.