Fast Design of Repeat Ground Track Orbits in High-Fidelity Geopotentials∗

The existence of families of periodic, repeat ground track orbits in full Geopotentials is demonstrated. The basic families are made of almost circular orbits except in the vicinity of the critical inclination (63.4/116.6 deg), where the eccentricity of the repeat orbits grows high for almost fixed inclination. Computation of specific repeat ground track orbits for mission designing purposes can be automated providing the nominal solution in a fast, straightforward way; this is illustrated with the computation of the TOPEX nominal orbit in a 140 × 140 truncation of the GRACE Gravity Model