STUDY OF MICROWAVE REMOTE SENSING OF THE SOIL MOISTURE

This article includes a study of the microwave emissivity characteristics of moist soil and the method of microwave remote sensing of the soil moisture. The relation between soil dielectric constant and moisture was measured with terminal short circuit line method. The microwave emissivity of soil decreases with the increase of humidity because the real andimage parts of dielectric constant increases with the humidity. The relation between soil microwave emissivity and humidity is measured with the microwave emissivity meter made by us. Considerable change of brightness temperature is caused by different soil humidity. This article also presents the exhausted depth and the influence of humidity distribution on emissivity, the effection of soil surface roughness on emissivity. The theoretical analysis and experiment results have shown that microwave radiometer is a helpful instrument in the remote sensing of soil moisture. 3.2 cm waveband, with higher sensibility, deeper penetrate depth and less effect o