Use of the Corsica site to compute altimeter biases for JASON-2/OSTM, JASON-1 and ENVISAT: Absolute and Regional CalVal methods

M Cancet, J Chimot, S Bijac, P Bonnefond, O Laurain, E Jeansou, F Lyard, E Bronner
In situ calibration: Regular long term control of the altimeter SSH measurements Independent of other altimetry missions Absolute CalVal method: For satellite passes flying directly over the calibration sites Jason-2 pass 085 in Senetosa Envisat pass 130 in Ajaccio Comparable to the bias estimation in Harvest, Bass Strait, Gavdos... Regional CalVal method: Enables to compute the bias on offshore passes, at crossover points: considering passes of the same mission or combining several missions
more » ... ngs back the offshore SSH to the calibration site following a succession of accurate mean profiles takes into account the spatial MSS gradient between the offshore crossover point and the calibration site Same behavior as Jason-2: decrease in the bias between the coast and the offshore altimeter data even if it is weaker. Not visible in the previous results computed with the GDR-A products (Jan et al., 2004) Jason-1 biases computed on a different and longer period Better retracking in the GDR-C products ? Better corrections (wet troposphere, SSB...) ?