Discussion On Methodology To Determine Soil Moisture Critical Value With That Loess Soil Is Presented As Non Lambert

When using remote sensing data to increase the discernment capability of the Earth surface, angle information was found to have influence and contribution to the identity and classification of object in remote sensing images. In fact, the full angle information of an object is its three-dimensional spectrum characteristics in 2Ï€space. Two approaches have been used to characterize the angle spectrum. The first one emphasizes on applications only. It assumes that a ground target is a Lambert object and ignores the angle differences. The other approach emphasizes the verity and difference of angle information. The Bidirectional Reflection Distributing Function (BRDF) has been used in information extraction. In the process of reflecting, scattering and transmitting electromagnetic wave, earth targets can represent polarized characteristics, which relate to their nature. Polarization includes more contents in describing dark targets (or low irradiance) and man-made targets, and can be another dimension of information source in remote sensing. The traditional remote sensing mainly detects the earth surface vertically to obtain its planar information, but it is difficult to get enough parameters for the quantitative remote sensing to invert earth targets. The multi-angle observation can get more detailed and reliable three-dimensional space structure parameters of targets, so that it is possible to realize the quantitative remote sensing. Therefore, the multi-angle polarized information detection of object has become a new method of quantitative remote sensing.We find that the soil which moisture is more than a certain value is represented as Non Lambert reflector, but when less than the value, the soil is represented as Lambert reflector. The paper builds the models between degree of polarization and soil moisture by collecting the data of degree of polarization with an example of black soil, and calculates the soil moisture when the degree is 0.The moisture is the critical value of Lambert reflector and Non Lambert reflector. Finally the results are verified and investigated in the experiments as well.