Analyzing radar backscatter of land within the TRMM footprint using high resolution SAR

Spaceborn precipitation radars acquire atmospheric measurements using beams that scan through nadir. Naturally, the reflection from the surface is typically quite strong, especially at nadir. This surface observation can be used to estimate the attenuation caused by precipitation provided there is a reasonable value of the non-attenuated surface return leading to an estimate of the rain rate. Over land, the backscatter characteristics are usually very dynamic and change in the presence of water due to its high dielectric constant. In addition, the viewing geometry results in very large beam footprints on the ground containing highly variable scattering mechanisms. Using a high resolution Synthetic Aperture Radar, the surface characteristics within this footprint can be examined with respect to how precipitation changes the backscatter. This research investigates both of these radar types, plus ground based weather radars, to quantitatively analyze surface dynamics within the footprint of a precipitation radar.