X-track, a new processing tool for altimetry in coastal oceans

Oceanographic applications using satellite altimeter data become very challenging when leaving the deep ocean for the coastal regions. Close to the coast, altimeter observations are often of lower quality for a number of reasons, including land contamination of the satellite footprints or inaccurate resolution of the corrections of the high frequency ocean response to tidal and atmospheric loading. This paper presents a new processing toolbox, called X-TRACK, to derive improved altimeter products, such as sea surface heights (SSH), mean sea surface heights (MSSH) or sea level anomalies (SLA), dedicated for coastal applications. Starting from classical geophysical data records (GDR) products, particular attention is made to recover a maximum amount of exploitable data (dedicated data editing, interpolation of missing corrective terms). Where possible, local modelling of the high frequency response of the ocean to the tidal and atmospheric loading is applied instead of standard, global corrections given in the GDRs. In addition, orbit errors are reduced by a stability criterion and a high resolution mean sea surface consistent with the altimeter data set is computed along the satellite ground track. This poster presents promising results obtained in various coastal areas.