Abstract—Microwave polarization difference index (MPDI) has great potential in soil moisture content and biomass inversion.Passive microwave remote sensing can be used for inversing surface parameters such as surface temperature, vegetation water content. Different terrain types have different polarization effects and radiation characteristics, and also present the differences by seasons due to its structure, moisture content, and roughness. Use monthly AMSR-E microwave brightness temperature data (25Km) under clear sky in 2010 and IGBP classification standard data (1KM), then analyses the MPDI characteristics and the MPDI season change rule of different surface types by choosing relatively pure pixels. Result shows that, MPDI has relationship with frequency, almost all MPDI of vegetations, water, bare soils decreased along with the increase frequency. In addition, MPDI have difference by seasons of different vegetation types, which has relationship with vegetation density and canopy characteristic; Snow cover also is a important factor in Northeast of China.

Keywords-Microwave polarization difference index(MPDI); vegetation types; AMSR-E;soil moisture content