Effects of atmospheric precipitation on spaceborne synthetic aperture radar measurements

Unlike space-based near-nadir viewing radars, X-SARs will mainly measure the slant-path integrated scattering and attenuation of precipitation in orthogonal oblique directions. A microwave model for simulating the normalized Radar Cross Section (NRCS) SAR response was set up in this work and exploited to train the proposed X-SAR retrieval algorithms. The rain-cloud 2-D shape was modeled as product of a horizontal and a vertical distribution function. An inversion approach, based on the Volterra Integral Equatio (VIE), was applied to a X-SAR/SIR-C case study. The VIE approach is a mathematically elegant way to treat the SAR inverse problem, but it needs to be generalized to vertically- inhomogeneous media to be useful in atmospheric applications.