Analysis of Brightness Temperature Models for Describing Surfaces by Passive Remote Sensing Methods

The National Aerospace University “Kharkiv Aviation Institute” has been conducting research for more than 10 years to optimize algorithms for processing radio-thermal radiation, improving the structures of microwave radiometers and developing own passive radars for aerospace applications. Last year it was developed ultra-wideband radiometer for a university nanosatellite with advanced bandwidth from 75 to 110 GHz. This passive radiometer is planned to be used to analyze the condition of the underlying Earth's surface. It is impossible to study the surface without a correct model of the relationship between its parameters, radiated electromagnetic fields and received signals. In this paper we analyze existing electrodynamic, empirical and regression models to describe the temperature of the underlying surface and determine the conditions of their application. The feature of the work is the study of the dependencies of the limiting errors of the developed ultra-wideband radiometer at different viewing angles, for different polarizations and for different estimated parameters.