Algorithms for the retrieval of rainfall from passive microwave measurements

Abstract

At frequencies below about 40 GHz over an ocean background the relationship between the rainfall and the observations is particularly well understood. In this part of the spectrum, the radiances are principally determined by the liquid hydrometers with only a modest amount of ambiguity. A total of 16 algorithms were submitted for the PIP-1. These include algorithms that are based on high frequency (scattering) measurements and low frequency (emission) measurements with a few combinations and variations on these themes. The calibration of the algorithms varies from mostly empirical to essentially first principles with most falling somewhere in-between. -from Authors