Mònica Roca (isardSAT, Spain); Graham Quartly (Plymouth Marine Laboratory, United Kingdom)

The Sentinel-3A is the most recent altimetric mission of a long historical series, and the first altimeter of the Copernicus constellation.

It is well known the crucial importance of the instrumental calibration when processing the altimeter data, in order to produce reliable and accurate L2 geophysical retrievals, such as sea surface height, significant wave height, or wind speed over the oceans.

isardSAT, as ESA Expert Support Laboratory within the Sentinel-3A Mission Performance Centre team, is responsible of monitoring the calibration parameters during the Sentinel-3A SRAL mission. This poster presents the monitoring results of up to date SRAL calibration data, acquired during the Commissioning and Routine Phases of the Sentinel-3A altimeter mission.

The SRAL altimeter permits to operate in two modes, LRM (low resolution) and SAR (high resolution) in two frequency bands, Ku and C. For the 4 combinations, CAL-1, CAL-2 and Autocal calibration modes are monitored and analysed from L1b data. Also the on-board thermal variations are monitored from L0 data. The on-board tracker performance is studied from L2 data.