Performances of the POSEIDON-1 radar altimeter

This paper describes the results of the performance analysis of the French radar altimeter, POSEIDON-1 (also called SSALT for Solid State Altimeter), flying on board the TOPEX/POSEIDON satellite. The results we present are issued from the analysis of eight years of data (from 1992 to 2000). They range from operation performance (availability, coverage...) to altimetric system performance (cross-over analysis, sea level analysis...) going through instrumental performances. It is shown that POSEIDON-1 is behaving well within its specification. Comparisons of the data set issued from POSEIDON-1 and TOPEX have been performed. Mutual benefits in term of data quality and characterizations are illustrated. The TOPEX/POSEIDON follow-on mission called JASON-1 will embark the dual frequency (Ku and C bands) POSEIDON-2 altimeter which inherits from POSEIDON-1.