Moritoring Wingter Wheat Growth With Grand Based Microwave Radiometers (GBMR)

Abstract

From November 2006 to June 2007 a field experiment ‘Tanashi Experiment’ was conducted in a farm of the University of Tokyo, Japan. Continuous ground measurements of meteorological variables, soil moisture and temperature profiles and vegetation status have been taken. At the same time, the ground based microwave radiometers (GBMR) are employed to provide accurate field measurements of brightness temperature up-welling from the plot, at the frequencies of 6.925, 10.65, 18.7, 23.8, 36.5 and 89 GHz. The scientific objectives are presented in this paper and the corresponding experiment set-up is described. The influences of vegetation layer on the brightness of various frequencies are analyzed. The TB of all frequencies and polarization is found to be saturated and reach same values when vegetation water content larger than 4 kg/m . Based on the analysis of winter wheat experiment results, the Polarization Index (PI) of 6.9GHz and the Index of Soil Wetness (ISW) calculated from 18GHz and 6.9GHz horizontal polarization were recommended to compose the look up table. Potential applications of this winter wheat microwave radiometer observation are the development and validation of land surface variables retrieval algorithm and the study of land surface process and the land atmosphere interaction, and. 2