Satellite Radar Altimetry to Measure Water Heights in Coastal and Inland Waters

Radar altimetry is a remote sensing technique to measure water height changes from space. It was originally designed to monitor deep oceans, however, it showed the possibility to extend observations to coastal zones and over land. The archive of almost two decades (since 1993) of altimeter data and the seven missions now flying together provide a unique global data set of water surface elevations. It has been used to complement in situ networks and provide measurements where no data exist or are not accessible. However, the retrieval of accurate water heights has been challenging in areas where land and water surface in homogeneity can contaminate the radar signal and complicate the algorithms for their estimation.