Double Frequency Retrieval of Rain Intensity Using Solution of the Integral Equation of Scattering

A solution for the inverse problem of rain remote sensing presented by Fredholm integral equation of the first kind is proposed in the case of microwave double frequency sensing and Tikhonov regularization. Performed numerical simulation showed that proposed approach permits to retrieve the rain intensity with error less than 20 % for rain intensities more than 5 mm/h and with an error of 60 % for intensities less than 5 mm/h (modeling was performed for radar operating wavelengths 0.82 and 3.2 cm and for a range of rain intensity 1 ÷ 30 mm/h).