Stationary SST estimation using ERS1 and TOPEX/POSEIDON data in the western mediterranean area

ERS 1 Exact Repeat Mission (ERM) and TOPEX/POSEIDON data have been analyzed trackwise to separate via collocation filtering the stationary SST from the time dependent SST in residuals between altimetric data and geoid model (GEOMED). The stacked tracks have been merged via a cross over adjustment assuming TOPEX/POSEIDON as reference frame. Using a 2-dimensional covariance function, estimated from stacked ERS1/ERM data, collocation filtering has been applied also to the Geodetic Mission data to separate the stationary SST from the time dependent part. The filtered geodetic tracks have been then trackwise connected to the reference frame defined by TOPEX/POSELDON and ERS1/ERM. Thus an improved estimate of the stationary SST has been obtained due to the dense coverage of data mainly related to the geodetic ERS1 mission.