The monitoring of the TOPEX-POSEIDON, ERS-1 and ERS-2 altimeters and microwave radiometers relative biases

J. Stum, F. Ogor, J. Dorandeu and P.Y. Le Traon		18 Av. Edouard Belin, 31401 Toulouse Cedex 4, FRANCE stum@metis.cnes.fr

Abstract

Long-term monitoring of the sea level variations requires that altimetric height measurements be inter-calibrated within a few millimetres. Inter-calibration means the determination of the relative biases and drifts between the range measurements of the different altimeters, as well as the determination of the relative biases and drifts between the measurements of the different microwave radiometers, which are used to correct the altimeter measurements for water vapour induced path delay. In a first step, results obtained for the inter-calibration of the TOPEX/POSEIDON, ERS-1 and ERS-2 altimeters over more than 4 years are given here and discussed. The second step is devoted to the 4-year long inter-calibration of the TOPEX/POSEIDON, ERS-1 and ERS-2 microwave radiometers.
Keywords: altimeter, microwave radiometer, relative bias, inter-calibration, sea level monitoring (max. 6)

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry