The Precise Range And Range-Rate Equipment (PRARE) was a microwave tracking system on board the ERS-1 and ERS-2 missions. It operated at centimetre accuracy levels for the measurement of satellite to ground range and range rate. The concept was based on an autonomous spaceborne two-way and dual frequency microwave tracking system with its own telemetry, telecommand, data storage, timing and data transmission capabilities. This allowed data analysis on a global basis within a very short time delay. Due to the microwave transmission concept, the system operated independently from weather and daylight conditions.
The initial PRARE system development started in 1982 in Germany as a response to ESA's announcement of opportunity for exploitation of Europe's new Earth-remote sensing satellite series starting with ERS-1. The project was funded by BMFT and DARA, defined/designed by Ph. Hartl (University of Stuttgart) and Ch. Reigber of DGFI (German Geodetic Research Institute), Munich and since 1992 of GFZ (GeoForschungsZentrum), Potsdam.
All PRARE (ERS) products, in accordance with ESA Earth Observation Data Policy, are freely available to registered users via FTP. Read more about the available products and the registration process which is required to access them: