Sentinel-6/Jason-CS Altimeter Products and Performance Budget

Remko Scharroo (EUMETSAT, Germany)

CoAuthors

Craig Donlon (ESA/ESTEC, The Netherlands); Gilles Tavernier (CNES, France); Christelle Ponsard (EUMETSAT, Germany)

Event: 2015 Ocean Surface Topography Science Team Meeting

Session: Outreach, Education and Altimetric Data Services

Presentation type: Type Poster

The Sentinel-6 (Jason-CS) mission will follow TOPEX and the Jason-series of altimeters as one of the "reference missions". But it is in many ways a totally new type of mission, a new platform (similar to CryoSat) and a new altimeter. Not only will it be the first Synthetic Aperture Radar (SAR) altimeter used on one of the reference missions, it will also be the first altimeter that operates in a continuous high-rate pulse mode, such that there is no longer the need to wait 2/3 of the time for pulses to be received, while transmitting only 1/3 of the time, like the altimeters of CryoSat-2 and Sentinel-3. On top of that, Sentinel-6 will be operating in this mode 100% of the time. This particular operating mode allows simultaneous production of low-resolution mode (LRM) measurements on-board as well as the processing of SAR echoes on-ground. Both types of measurements will be provided in (separate) Sentinel-6 altimeter data products.

Sentinel-6 will bring some unique opportunities for cross-calibrating and cross-validating LRM and SAR altimetry, housed on the same platform, working from the same altimeter echoes, just different processing. Also, it will be the first time that we will be able to fully process on-ground 100% of the echoes that would otherwise be averaged on-board. This presentation will show how this is reflected in the Sentinel-6 products, how these compare with the products of the Jason-series and how continuity is ensured. Of course, at the same time EUMETSAT is striving to allow a good synergy with altimeter products from the Sentinel-3 mission.

The baseline for Sentinel-6 is to provide near-realtime (NRT) products compatible with those of the previous missions within 3 hours. Additionally, slow-time-critical (STC, latency 36 hours latency) and non-time-critical (NTC, 60 days latency) products will be made available with all of the variables needed to fully exploit and analyse the SAR and LRM mode data.

In addition, Level 1 products will be made available containing all the individual echoes in the time domain (L1A) or the measurement data and waveforms without geophysical corrections (L1B). A L1B-S product, with the individual waveforms stacked and geo-located such as is available for Sentinel-3, is not part of the planning, as these data products can be derived from the L1A directly.

During the process of writing up the Mission and System Requirement Documents, the performance budget for the Jason-CS satellites was painstakingly scrutinized, ensuring that Sentinel-6 would provide the end user with measurements of sea level, wind speed, and wave height with at least the precision and accuracy of the Jason-2 mission in LRM, and pushing the boundaries on the expected SAR mode performances. The final performance budget for both operating modes and for the various product latencies is reported in this presentation as well.
 

Poster show times:

RoomStart DateEnd Date
Grand Ballroom Foyer Thu, Oct 22 2015,11:00 Thu, Oct 22 2015,18:00
Remko Scharroo
EUMETSAT
Germany
remko.scharroo@eumetsat.int