Study Of Radar Scattering Model Under Waves Breaking And Its Application

Electromagnetic waves in various bands of surface reflection, scattering or spontaneous emission carry various information about surface temperature, sea level height, sea surface roughness, as well as concentrations of a variety of substances contained in sea water. Wave breaking is an important phenomenon in the ocean, and wave breaking supports air–sea fluxes of heat and gas, which have a profound effect on weather and climate. However, it will be a complex problem to retrieval the ocean parameter, with scattering model, due to the increased the sea surface roughness caused by breaking waves. Thus, it is necessary to deal with the issue of radar scattering under wave breaking.This thesis focuses on the two models of radar scattering, and investigated the influence of the waves breaking on the scattering of electromagnetic waves from the sea surface. Two new relationships between the wave breaking coverage and the wind speed are proposed based on the improved Kudryavstec03 mode. Meanwhile, an implicit model for retrieving wind speed is proposed with high accuracy. For microwave scattering models from breaking wave, the major contents in this thesis are as follows:1. Based on the Kudryavstec03 model, wave breaking coverage is replaced by whitecap coverage of Huang. Moreover, both the results of Bragg scattering model and Kudryavstec03 model are compared with the ERS-1 scatterometer data. It is shown that the Kudryavstec03 model considering the breaking wave is superior to pure Bragg scattering model for the same conditions.2. The Kudryavstec03 model is improved by multiply a function of incidence so that the result of model consistent with ERS-1 data. Research shown that the results obtained from the improved Kudryavstec03 model much better than those of original model for the angle of incidence from 18o to 35o to compare with data measured by ERS-1 scatterometer. The improved model can be used to retrieve3. Based on the improved model and scatterometer data, two new relationships between wave breaking rate and the wind speed are obtained from retrieving the wave breaking rate in the rang of 30o-35o for the angle of incidence.4. With the improved model and newly proposed the wave breaking rate, wind speed is retrieved with higher accuracy in the rang of 30o-35o for the angle of incidence5. A variety of oceanic physical parameters are calculated by some the experiential relationships between those parameters and wind speed, such as whitecap coverage.