Correlated observations by the ERS-1 and multi-channel SSM/I and data simulation from theoretical models of random media

Most advances of satellite-borne microwave remote sensing in the nineties can be demonstrated by global surveys by the ERS (European Remote Sensing Satellite) and DMSP (Defense Meteorological Space Program) sensors. It has become a primary source for microwave data interpretation and derived hydrological products. However, the correlative characteristics of the backscattering coefficient and brightness temperature measured respectively, by active scatterometers and passive radiometers on the same area have not been closely studied. It remains to be answered whether the measurements by active ERS scatterometer and passive SSM/I radiometers are mutually consistent and supplemental, and how both active and passive measurements can resolve ambiguity in data interpretation and inversion. In this paper, some data collected from ERS-I and SSM/I observations on China ocean regions, Greenland and Siberia snow, etc. are presented for the analysis of active/passive correlation and comparison of model simulation. Rough sea surface is modeled as a two scale rough surface with foam-particle cover. Backscattering bistatic scattering and thermal emission over the ocean are calculated for both ERS-I and SSM/I channels. Snow is a dense scattering medium or is seen as a strongly-fluctuating medium. By using the dyadic Green´s function of stratified media and the Born approximation, backscattering from multilayer snow is calculated for ERS data simulation. The vector radiative transfer equations of thermal emission from multi-layer media of dense scatterers is solved for SSM/I snow data simulation