Conventional and new approaches for combining multi-satellite techniques

Abstract

The combination of different space geodetic or satellite techniques offers the possibility to determine more complete, reliable, and accurate reference frame parameters. Two new approaches are proposed: the onboard collocation and the integrated method. The onboard collocation utilizes the availability of different techniques onboard a Low Earth Orbiting (LEO) satellite. For the CHAMP and GRACE satellites, and for the GPS-35 and -36 satellites, the radial distances between the Global Positioning System (GPS) phase centers and the Satellite Laser Ranging (SLR) retroreflectors are examined. The integrated method treats a multi-satellite configuration with measurements by various tracking techniques on the observation level. From three months of observations from the GRACE/GPS constellation, a series of low degree harmonics of the Earth's gravity field, representing dynamical geocenter location and axes orientation, is determined with high accuracy and daily resolution. © 2006 Springer-Verlag Berlin Heidelberg.