Future Altimeter Missions Capability in the Coastal Zone

Ocean monitoring using satellite radar altimetry is a well-established discipline, which utilises primarily pre-processed data supplied by the Space Agencies. However, the availability of these data decreases rapidly within 10 km of the coast, as the echo shapes become contaminated with signal components from land topography and comparatively still water surfaces such as harbours and estuaries. Retracking these echoes can recover much of this lost data. However, the next generation of satellite radar altimeters allows a substantial improvement in coastal zone measurements to be made, as the higher along track sampling rate permits the component parts of these complex echoes to be disentangled. This paper presents a first assessment of this enhanced capability, using both burst echo data from the EnviSat RA-2 (obtained at 1800Hz rather than the 18Hz normal data sampling frequency) and the results of simulation runs in the coastal zone for CryoSat2, obtained from the CRYMPS simulator. The results show that a dramatic enhancement of measurement potential in this complex and rapidly evolving environment may be expected from the next generation of Synthetic Aperture Radar Altimeters.