Waves can be measured from space using active sensors such as altimeters, which provide estimations of the significant wave height at nadir along the satellite track, or Synthetic Aperture Radar (SAR) which provides directional spectra of long waves (swell, > 70m wave length) every 100 km along Sentinel-1 series track, or the new SWIM instrument onboard CFOSAT providing directional measurements over a 140 km wide swath at a resolution of approximately 50km.
Wave observation from radar spaceborne sensors is a major research topic at Ifremer/LOPS, with an active support and involvement in several ESA or CNES missions such as ERS series, Envisat, CFOSAT and Sentinel-1 series, and dedicated products and services.
Waves at Ifremer / LOPS
The research activities on wave parameters from remote-sensing focus on different aspects:
- development of processing algorithms for the retrieval, intercalibration or denoising of wave measurements from SAR, CFOSAT/SWIM and altimeters
- involvement in the design, definition and preparation of future satellite missions
- cal/val and long-term monitoring of existing instruments and missions, such as CFOSAT or Sentinel-1 series (ESA / Mission Performance Center - MPC)
- definition of science products and services for the user community
In particular CERSAT delivers:
- long time series of intercalibrated altimeter and SAR wave products (1992 to 2020) for the ESA/Climate Change Initiative (CCI) Sea State project, from along-track measurements to monthly averages
- innovative research products for French/Chinese CFOSAT wave and wind measuring mission through the Ifremer Wind and Wave Operation Center (IWWOC)
- resources for the validation and intercomparison of remote sensing data, such as mission cross-overs or match-ups with in situ and model data