Adjustment of the dual frequency altimeter low subsection backscatter coefficient statistical model

摘要

The Ku band and C band backscatter coefficient statistical relationship plays an important role in dual frequency altimeter wind speed retrieval when it is rain. In order to improve the precision of wind speed retrieval, it is very important to put forward a proper statistical relationship. Jiang’s relationship has higher precision than Quartly’s and Yang’s relationship between 12dB and 26dB. But if C band backscatter coefficient is 12dB, the wind speed is 27.3683m/s, so if the wind speed is larger than 27.3683m/s, Jiang’s relationship can’t work. High wind speed condition is one of the most important sea phenomena, so we eagerly need to build a new relationship that can apply to the entire sea phenomenon. This paper is based on the specular scattering theory, analyses the low backscatter coefficient subsection’s relationship, put forward a method that if C band backscatter coefficient is between 12dB and 26dB, Jiang’s relationship is used, if C band backscatter coefficient is smaller than 12dB, Yang’s relationship is used. This relationship redounds to improve wind speed retrieval when it is rain.