Abstract's details

Fully Focused SAR Altimetry and Innovative River Level Gauges for Coastal Monitoring – the FFSAR-Coastal Project

David Cotton (Satellite Oceanographic Consultants Ltd, United Kingdom)


Ole Balthazar Andersen (DTU Space, Denmark); Heidi Ranndal (DTU Space, Denmark); Jean-Christophe Poisson (vorteX.io, France); Charlie Thompson (Channel Coast Observatory, United Kingdom); Amani Becker (National Oceanography Centre, United Kingdom)

Event: 2022 Ocean Surface Topography Science Team Meeting

Session: Coastal Altimetry

Presentation type: Type Poster

The recently developed technique of “fully focused” processing of SAR altimeter data provides opportunities for exciting new applications, as it provides hitherto unachievable along-track resolution of up to (and in some cases less than) tens of metres.
The objective of the FFSAR-Coastal Project is to apply the SMAP Fully Focused SAR (FFSAR) altimetry processor on Sentinel-3A and Sentinel 3B data and evaluate the potential of FFSAR altimeter data to make a significant new contribution to coastal and estuarine monitoring systems.
Two different environments are being considered:
• The Severn Estuary and river: A highly dynamic mixed tidal estuary environment, the confluence between a river and its estuary experiencing large tidal range and strong tidal currents.
• The lower Rhone Delta and Camargue: A low lying, flat river delta and wetland environment, susceptible to inundation and rising water levels.
By studying these two very different environments, the potential applicability and benefits offered by FF SAR altimeter data in other coastal, estuarine and delta locations will be demonstrated.
Innovative in situ lidar water level gauges, provided by vortex.io will be used for validation.

FFSAR-Coastal is funded by ESA under the EO Science for Society Programme – Open Call.

The presentation will provide an overview of the FFSAR Coastal project and present early results.

There are two main elements to the project.

DTU Space are using the SMAP (Standalone Multi-Mission Altimetry Processor), developed by CLS, and applying it to Sentinel 3A and 3B altimeter data for two regions with very different characteristics: the Severn estuary in the UK, and the Rhône delta in France. The objective is to evaluate how well FFSAR altimeter data can resolve fine scale features in these two different environments. Initial results will be used to identify the optimum processing choices, which will then be applied to generate time series of data for selected tracks. These data will be validated against in-situ data and models, to quantify the performance against other data sources. Further analysis will then investigate the capability of FFSAR altimeter data to capture small scale physical signals (surface gradients, currents, roughness signatures) in highly tidal regions and to detect and measure tidal asymmetry/gradients across estuaries not seen with conventional altimetry
For the Rhône delta the analysis will focus on the ability of FFSAR data to accurately map different low lying channels and filaments.

The second element is the deployment of innovative river level “micro-gauges” (vorteX.io microstations) to provide ground truth data, and to test these as a flexible and low-cost option for satellite validation and river monitoring. Two micro-gauges will be installed in each of the selected regions, as close as possible to the Sentinel 3A and 3B ground tracks, and drone campaigns with an embedded LiDAR altimeter will be carried out to provide high resolution sea level measurements, synchronised to satellite overpasses, to provide a water level profile between the micro-gauge location and the satellite ground track.

The project is also engaging with local user groups to identify key gaps in the existing monitoring systems, and to develop recommendations on how FFSAR altimeter data can best be used as part of

Poster show times:

Room Start Date End Date
Mezzanine Tue, Nov 01 2022,17:15 Tue, Nov 01 2022,18:15
Mezzanine Thu, Nov 03 2022,14:00 Thu, Nov 03 2022,15:45
David Cotton
Satellite Oceanographic Consultants Ltd
United Kingdom