Soil Moisture Retrieval from Brightness Temperature using Passive Microwave Remote Sensing

Abstract

Soil Moisture (SM) data are often a derived product of Microwave Remote Sensing (MRS) satellites. The brightness temperature (Tb) however, is a basic quantity associated with the satellites in the Microwave range and is available as a common data product from all MRS satellites. In this paper an attempt has been made to develop an algorithm to retrieve SM information directly from the Tb values obtained from the Advanced Microwave Scanning Radiometer on Earth Observing (AMSR-E) System. Analysis of Tb and SM data is done to find the most suitable frequency band and polarization at which the conversion from Tb to SM is possible. Out of all the frequencies from the satellite, the Tb values at 6 GHz frequency with horizontal polarization have been found to be most suitable for SM retrieval. The algorithm designed is found to be applicable for Tb to SM conversion for any season.

Keywords: Microwave remote sensing, soil moisture, AMSR-E, brightness temperature, passive sensors