Gravity-field determination from laser observations

Abstract
Knowledge of long-wavelength features of the geopotential is significantly improved by the use of precision satellite tracking with lasers. Tracking data on nine satellites are combined with terrestrial gravimetry to obtain a spherical-harmonics representation of the geopotential complete through degree and order 24. An improved gravity-field model provides better satellite ephemerides and a reference for analysing satellite-to-sea-surface altimetry.