Abstract's details

Jason-3 & Sentinel-6 MF calibration at the Corsica facilities

Pascal Bonnefond (Observatoire de Paris - SYRTE, France)

CoAuthors

Olivier Laurain (OCA/Géoazur, France); Pierre Exertier (GET, France); Thierry Guinle (CNES, France); Pierre Féménias (ESA/ESRIN, Italy)

Event: 2022 Ocean Surface Topography Science Team Meeting

Session: Regional and Global CAL/VAL for Assembling a Climate Data Record

Presentation type: Type Poster

Initially developed for monitoring the performance of TOPEX/Poseidon and follow-on Jason legacy satellite altimeters, the Corsica geodetic facilities that are located both at Senetosa Cape and near Ajaccio have been developed to calibrate successive satellite altimeters in an absolute sense. Since 1998, the successful calibration process used to calibrate most of the oceanographic satellite altimeter missions has been regularly updated in terms of in situ instruments, geodetic measurements and methodologies. In this study, we present an assessment of the long-term stability of the in situ instruments in terms of sea level monitoring that include a careful monitoring of the geodetic datum. Based on this 20+ years series of sea level measurements, we present a review of the derived absolute Sea Surface Height (SSH) biases for the following altimetric missions based on the most recent reprocessing of their data: TOPEX/Poseidon and Jason-1/2/3, Envisat and ERS-2, CryoSat-2, SARAL/AltiKa and Sentinel-3A&B. For the longest time series the standard error of the absolute SSH biases is now at a few millimeters level which is fundamental to maintain the high level of confidence that scientists have in the global mean sea level rise.
Launch in November 2020, Sentinel-6 Mickael Freilich flew in tandem with Jason-3 during its first year of mission. We will present in detail the analysis of this tandem phase. Preliminary results shows that the absolute SSH bias for both missions are very close at the 1 cm level for the LRM mode and both very close to 0. Improvement thanks to SAR will be also presented: measurements are valid (and accurate) up to the coast (few hundred meters); on the whole set of cycles, the standard deviation of 20Hz data is improved by a factor close to two: 33 mm compared to 56 mm with LRM (69 mm for Jason-3).
In preparation of SWOT, an extension of the "geoid" over the Ajaccio and Senetosa area has been realised during 2 campaigns in 2021 and 2022. Prelimininary results will be also presented.
 

Poster show times:

Room Start Date End Date
Mezzanine Tue, Nov 01 2022,17:15 Tue, Nov 01 2022,18:15
Mezzanine Thu, Nov 03 2022,14:00 Thu, Nov 03 2022,15:45
Pascal Bonnefond
Observatoire de Paris - SYRTE
France
Pascal.Bonnefond@obspm.fr