Abstract's details

Sentinel-6/Poseidon-4 altimeter end-to-end simulator to assess the global mission performances

Jeremie Aublanc (CLS, France)

Thomas Moreau (CLS, France); Pierre Dubois (CLS, France); Yolanda Maya-Soriano (CLS, France); Pierre Thibaut (CLS, France); Francois Boy (CNES, France); Gilles Tavernier (CNES, France); Gérard Zaouche (CNES, France); Marco Fornari (ESA, Netherlands); Mieke Kuschnerus (ESA, Netherlands); Robert Cullen (ESA, The Netherlands)

Event: 2017 Ocean Surface Topography Science Team Meeting

Session: Instrument Processing: Measurement and Retracking

Presentation type: Poster

Sentinel-6 mission is part of the Copernicus program, with the aim to continue the Jason series of operational oceanography missions for the period 2020-2030. Two Sentinel-6 satellites will carry a dual-frequency Ku/C-band radar altimeter (Poseidon-4) with significant evolutions with respect to their predecessors. Among other evolutions, Poseidon-4 will operate in Delay Doppler Mode (DDM), as Cryosat-2 and Sentinel-3A and B, but using an innovative interleaved mode, where pulses will be emitted and received at a regular high-repetition rate (9kHz) (unlike Cryosat-2 and Sentinel-3 operating in "burst mode"). That way, conventional Low Resolution Mode (LRM) and Synthetic Aperture Radar (SAR) mode data will be generated simultaneously. The consequence is that the noise of SAR altimeter ranges should be significantly reduced (by a factor of 1.7 when compared to Sentinel-3 SAR mode). For the sake of continuity with historical missions (Jason series), low- and high-resolution products will be generated with usual data processing, called baseline processors in LR and HR modes. Besides that, the altimeter mission will experiment new products and process developments (called experimental processors).

In the frame of the Sentinel-6 ground prototype processors (GPP) development, and under ESA contract, CLS is in charge of the definition of the level-2 prototype processor, its development and testing. The Level-2 GPP consists of four processors (two baseline and two experimental processors), each of them enabling to generate geo-located geophysical retrievals from high- or low-resolution waveforms. Furthermore, the Level-2 GPP contains new innovative retrackers (in LR and HR modes), ensuring high-performances and notable benefits in comparison with conventional ones.

In parallel to this development, CNES has funded CLS for designing and developing a Sentinel-6 altimeter simulator (including a Level-1 processor), which, combined with the L2 GPP, will form an end-to-end simulator of the Sentinel-6 Poseidon-4 measurement and processing. The Sentinel-6 altimeter simulator consists of a scene generator, and on-board and -ground processors to simulate and generate the level-1B products as defined for the mission. One of its major asset is its ability to simulate realistic oceanic scenes with a large list of possible scenarios. Alternative configurations with coastal or hydrological surfaces are also possible. Consequently, this newly-designed end-to-end simulator will permit to conduct performance evaluations of the instrument system over different types of surface (open ocean, coastal zones, river and lakes and other land areas) and to design and to assess any innovative L1/L2 processing.

This poster describes the different units of the Sentinel-6 altimeter end-to-end simulator and its major characteristics. First validation results demonstrating the potential of this simulator will also be provided.

Corresponding author:

Jeremie Aublanc

CLS

France

jaublanc@groupcls.com

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