Looking for systematic error in scale from Terrestrial Reference Frames derived from DORIS data

Abstract

The long-term stability of the scale of Terrestrial Reference Frames is directly linked with station height determination and is critical for several scientific studies, such as global mean sea level rise or ocean circulation with consequences to global warming studies. In recent International Terrestrial Reference Frame (ITRF) solutions, the DORIS technique was not considered able to provide any useful information on scale (derived from VLBI and SLR). We have analyzed three different DORIS time series of coordinates (GSFC, IGN/JPL, LEGOS/CLS) performed independently using different software packages. In the long-term, we show that the DORIS technique, due to its very stable and geographically distributed network, has extremely good stability (<0.1 ppb/yr). In the short-term, the three groups show systematic errors in scale (up to 5 ppb) that could come from their specific analysis strategies. Furthermore, we have investigated on a shorter time period (2004) new results for single-satellite solutions. This analysis is a first step in understanding the systematic errors currently seen in the DORIS-derived scale from different groups. © Springer-Verlag Berlin Heidelberg 2007.