Mapping the Earth’s Gravity Field with Orbiting GPS Receivers

摘要: The orbit of an artificial satellite is shaped primarily by the force terrestrial gravitation. If earth were a perfect and homogeneous sphere, would be simple Keplerian ellipse. planet closer to flattened ellipsoid than sphere; pull its equatorial bulge causes turn within plane at constant rate (precession perigee), also slowly rotates about earth’s axis line nodes). But actual shape mass distribution much more complex for flattened, ellipsoid. Departures from this simpler body cause irregularities (anomalies) in gravity field that produce “wiggles” or perturbations orbit. These departures precessing ellipse can sensed with tracking systems measure instantaneous distance velocity along sight tracker.