Introduction

Geodetic interest in DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite) resides in its reasonably dense and homogeneous tracking network that includes large number of collocations with other space-geodetic techniques. That is why the International DORIS Service was officially created by the International Association of Geodesy (IAG) in 2003. Several Analysis Centers contribute to IDS using different software packages. With the aim to make a new software package available and to stimulate further use of DORIS within the geodetic scientific community, Institut Géographique National (IGN) approached the Astronomical Institute University of Berne (AIUB) with an idea to implement DORIS analysis capabilities into the Bernese GPS software version 5.0. Additional step on the developments was gained when Geodetic Observatory Pecný (GOP) begun to participate in the ongoing work in 2003 with the interest to establish the Analysis Center. Today, after a long evolution, the DORIS-capable development version of the Bernese GPS software exists, allowing estimation of the parameters relevant for this satellite-geodetic technique. The quality of the data processing has been proven by the long data time-series analysis (from 1993.0 to present) and GOP became a relevant Analysis Center (AC) of IDS in 2007.

Long time-series of the station coordinates and the polar coordinates, derived from the free-network solution, have been estimated by several ACs. Although the input data are the same, the results are far from exact meeting due to a different approach, used software platform and models. Solution of every AC is thus specific. The GOP analysis center started to deliver the sinex files (in 2008), corresponding to the free-network solution. These files as well as the detailed solution description can be downloaded from IDS data centers, e.g. ftp://cddis.gsfc.nasa.gov/doris/products/sinex_series/gopwd/.