Project Description


Sentinel 6/Jason-CS Poseidon 4 L1 Ground Processor Prototype is an operational oceanography programme of two satellites that will ensure continuity to the Jason series of operational missions.

The main payload of the Jason-CS satellite 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). Poseidon-4 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 will be 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 will allow 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 mission is being developed by a multi Agency partnership consisting of ESA, EUMETSAT, NOAA, CNES and NASA-JPL. ESA is responsible for the Jason-CS Space Segment development along with Astrium GmbH as a prime contractor.


isardSAT is developing the Ground Prototype Processor for the Poseidon-4.


This prototype processes all the chains starting from the Instrument Source Packets, and up to the Level 1B (calibrated pulse-width limited or multi-looked SAR data). The prototype has been verified using simulated data generated by the Sentinel 6/Jason-CS mission performance simulator and also using in-orbit CryoSat data adapted in format to Jason-CS. These data have been provided by ESA.

Project Details

  • Team

    This project is lead by.

  • Duration

    2011-2021

  • Tags

    • Algorithm Development
    • Ocean and Coast
    • Hydrology
    • Sentinel-6