Envisat RA-2 satellite altimetry in coastal and inland waters: a comparison of retrackers

Radar altimeters made measurements of surface water levels possible from space. The technique wasoriginally designed for use in the open ocean, but now, with more interest in the coastal zone, many in thesatellite altimetry community are working on the development of retracking algorithms and improvedatmospheric corrections. It is important to recognize that the previous technical challenges are common tosatellite altimetry over any water body, but the issues are especially challenging in coastal and inland watersdue to their specific morphological and dynamic characteristics. The Envisat RA-2 mission provides a 35-day revisit time, with a maximum of 300 m resolution along track. It has collected altimeter data over thewhole globe since 2002. Within the COASTALT project, this historic archive of observations is accessible,with the addition of retrackers optimized for non-open ocean targets. This poster reports the results ofanalysis of standard and retracked data over an initial selection of water surface targets (coastal zone, estuaryand lake), presents examples of time series derived from these data and discusses agreements/disagreements.