The influence of a fallacy in specific effective scattering surface evaluation on the result of double-frequency retrieval of rain intensity

Abstract

Subject and Purpose. The amount of precipitation is important information for the agro-climatic justification of agro-technical and reclamation actions directly controlling crop yields. The inverse problem of rain intensity retrieval from the remote sensing data is an incorrect mathematical physical problem described by a nonlinear integral equation. The purpose of this work is to analyze how errors in the specific effective scattering surface evaluation affect the results of double-frequency retrieval of the rain intensity obtained through the inverse problem solution by the previously proposed method. Methods and Methodology. Numerical simulation by using an approach based on regularization techniques and intended for the integral scattering equation solution is carried out for double-frequency sensing in the microwave range Results. Numerical simulations of the rain intensity retrieval have been performed at the operating wavelengths 0.82 and 3.2 cm in the range 1…30 mm/h and for different values of received power errors. It has been shown that an error in the specific effective scattering surface evaluation has a greater effect on the reliability of the intensity retrieval in the shorter wavelength case. And it exerts practically no effect (not exceeding 5 %) at the longer wavelength and at the rain intensity below 15 mm/h, which, however, is true for heavier rains, too. Conclusion. The analysis of the results has shown that the error of the rain intensity retrieval remains within acceptable limits (below 20 %) provided that the error in the specific effective scattering surface evaluation does not exceed 15 % at the shorter wavelength. At the longer wavelength, it can reach 30 %.