GPD WET TROPOSPHERIC CORRECTION FOR ALL ESA AND REFERENCE ALTIMETRIC MISSIONS

摘要

In the scope of the ESA Sea Level Climate ChangernInitiative project, aiming to provide a uniform wetrntropospheric correction (WTC) for all altimetricrnmissions, the GNSS-derived path delay (GPD)rnalgorithm for computing the WTC, developed at thernUniversity of Porto was, after a “round-robin” selectionrnprocess, implemented for the main six altimetricrnmissions: TOPEX/Poseidon, Jason-1, Jason-2, ERS-1,rnERS-2 and Envisat.rnThis paper presents an overview of the GPDrnimplementation for these missions.rnThe GPD products have been validated by comparisonrnwith the WTC adopted as the reference correction byrnthe Archiving, Validation, and Interpretation of SatelliternData in Oceanography (AVISO): the so-calledrncomposite correction (Comp) for all missions except J2rn- for J2 the GDR-D Microwave Radiometer (MWR)rnWTC is the current AVISO reference. Various sea levelrnanomaly (SLA) statistical analyses have been performedrnand are summarized in this paper: SLA variance atrncrossovers; SLA variance difference as function ofrndistance from the coast or function of latitude;rndifference in regional sea level trends.