The Copernicus Sentinel-6 mission is an operational oceanography programme of two satellites that ensures continuity to the Jason series of operational missions, allowing mapping out global sea surface levels with higher precision. The mission is being developed by a multi-Agency partnership consisting of ESA, EC through Copernicus programme, EUMETSAT, NASA-JPL, and NOAA.
The main payload of the first Sentinel-6/Jason-CS satellite (Sentinel-6 Michael Freilich) is the Poseidon-4 radar altimeter that has evolved from the altimeters on-board the Jason satellites (Poseidon-2 of Jason-1, Poseidon-3A of Jason-2, and Poseidon-3B of Jason-3); and also inherits the Synthetic Aperture Radar (SAR) Altimeter mode of CryoSat-2 SIRAL and Sentinel-3 SRAL now proven to reduce errors in elevation and SWH retrieval over ocean. Furthermore, Poseidon-4 is the first radar altimeter embarked on a satellite that includes improved digital and radio frequency hardware and, in particular, open burst Ku-band pulse transmission (an operation currently termed the interleaved mode), that performs a near continuous transmission of Ku-band pulses, that allows SAR and pulse limited data to be gathered simultaneously. As with the Jason series and Sentinel-3, the Poseidon-4 transmits C-band pulses in order to retrieve a correction for ionospheric path delay.
The Payload Data Acquisition and Processing (PDAP) component, which is part of the Sentinel-6 Overall Ground Segment (S6 OGS), acquires data from the Sentinel-6/Jason-CS satellite and performs end-to-end processing. The development of the PDAP is funded by the EUMETSAT Jason-CS programme, the organisation’s contribution to the cooperative development of Copernicus Sentinel-6 (Jason-CS) mission. The first Sentinel-6/Jason-CS satellite (Sentinel-6A) was launched at the end of 2020.
isardSAT was responsible for the development of the Altimeter Level-1 Product Generation Function (ALT L1 PGF), within the S6 Payload Data Acquisition and Processing (S6 PDAP) project, which processes the altimeter data to provide operational L1 products. The development of the operational processors finished in 2020, further evolutions were implemented, and isardSAT is now in charge of both Altimeter Level-1 and Level-2 Product Generation Function maintenance.