Integration Of Space Geodetic Techniques As The Basis For A Global Geodetic-Geophysical Observing System (Ggos-D): An Overview

The objective of the GGOS-D project was the investigation of the technological, methodological and information-technological realization of a global geo-detic-geophysical observing system, especially the integration and combination of the space geodetic techniques. In the course of this project a data management and information system has been developed and implemented, very consistent long time series for GPS, VLBI and SLR were generated based on common state-of-the-art standards for modeling and parameterization, and these series were combined to compute a Terrestrial and a Celestial Reference Frame with very high accuracy and consistency. These reference frames were subsequently used as the basis to produce time series of geodetic and geophysical parameters like site coordinates, Earth orientation parameters (EOPs), troposphere parameters and low-degree gravity field coefficients. Finally, these time series were compared, validation and interpreted in order to improve our knowledge of the Earth system behavior.