Laser ranging error budget for the Topex/Poseidon satellite

A laser ranging error budget is detailed, and a specific error budget is derived for the Topex/Poseidon satellite. A ranging uncertainty of 0.76 cm is predicted for Topex/Poseidon at 20 deg elevation using the presently designed laser retroreflector array and only modest improvements in present system operations. Atmospheric refraction and satellite attitude effects cause the predicted range error to vary with satellite elevation angle from 0.71 cm at zenith to 0.76 cm at 20 deg elevation. This a priori error budget compares well with the about 1.2-cm rms a posteriori polynomial orbital fit using existing data taken for an extant satellite of similar size and orbit.