Processing DORIS Data with the GlPSYlOASlS II Software: Recent Results for Point Positioning and Orbit Determination

Pascal Willis, Willy Bertiger

Abstract:	The french DORIS system, launched for the first time in january 1990 on the SPOT2 satellite has proved its capabilities for precise orbit determination and point positioning. Since then, two additionnal satellites are currently carrying a DORIS rcceivcr (Topex/Poseldon, since August 1992 and recently SPOT3, since September 1993). The purpose of this paper is to present rcccnt results obtained with the GIPSY/OASIS II soflware developped at JPL, and presently used at IGN/Francc. Several improvements have been done since Ihc very beginning of the DORIS system: use of precise gravity fields models, such as JGM-2, determination of empirical accelerations for the satellite orbit, precise surface force modelling for T/P,... Results will be showned for precise orbit determination in the case of the US-French Topex/Pose’idon oceanographic mission. Comparisons will be performed with the precise orbit obtained al JPL using the GPS data in Ihe new rcduccd dynamic approach. DORIS data were also computed for point positioning using the free network approach (using very low constraints on ground stations coordinates). It is now possible to obtain a lo-cm accuracy absolute positioning using only 1 day of data in most cases. Recent resuhs will also be presented using broader time spans of DORIS data (typically months). Best solutions show now agreement with the IERS Terrestrial Reference Frame at the 2.1 cm level. As a preliminary study, Earth Rotation Parameters were also estimated for l-day DORIS data span, showing consistency at the 2 mas level with the IERS solution. For each topic, orbit determination and point positioning, the strategy of the computation will be discussed and results will be presented.
Published in:	Proceedings of the 1994 National Technical Meeting of The Institute of Navigation January 24 - 26, 1994 Catamaran Resort Hotel San Diego, CA
Pages:	615 - 624
Cite this article:	Willis, Pascal, Bertiger, Willy, "Processing DORIS Data with the GlPSYlOASlS II Software: Recent Results for Point Positioning and Orbit Determination," Proceedings of the 1994 National Technical Meeting of The Institute of Navigation, San Diego, CA, January 1994, pp. 615-624.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In