Simulation of Nearshore Altimeter Echo and Reliability Determination of SWH Data

This paper presents a method for simulating the echoes and retrieving the significant wave height(SWH) parameter of a nearshore radar altimeter. In nearshore regions, the sea surface echoes are often distorted due to the interference from islands and land, which introduces errors in the retrieval of the SWH. In this study, a composite rough surface is simulated to calculate the backscattering coefficients and time delays at each surface element. The radar equation is then employed to compute the echo power at each surface element, thus obtaining the complete radar altimeter echoes. These simulated altimeter echoes are used to retrieve the SWH of the sea surface. By varying the distance between the altimeter sub-satellite point and the land-sea boundary, the impact of different distances on the altimeter echoes is investigated, and the minimum distance that does not affect the retrieval of SWH is determined. This provides guidance for ensuring the effectiveness of nearshore radar altimeter data.