Method for inverting surface soil physical parameters through passive microwave remote sensing

Abstract

The invention discloses a method for inverting surface soil physical parameters through passive microwave remote sensing. The method comprises the steps as follows: step one, brightness temperature data and MPDIes (microwave polarization difference indexes) of an AMSR-E passive microwave remote sensing brightness temperature image are acquired by a launched satellite-borne passive microwave remote sensing meter AMSR-E; step two, a relationship of smooth surface reflectance, surface soil roughness parameters, MPDIes and vegetation optical thickness is acquired through deduction; step three, surface soil humidity mv and soil roughness h are calculated; and step four, the surface soil temperature TS is calculated. The method is based on a simplified passive microwave radiation transfer equation and combined with the MPDIes, a Q/H surface soil roughness model, a vegetation optical thickness model, a Fresnel equation and the like, so that a physical inversion model for the surface soil determinant attribute parameters including the soil temperature, the surface soil temperature and the soil roughness is constructed; and the method can be used for inverting the surface soil temperature, soil humidity and surface roughness distribution of China and even the global region and has important scientific significance.

Description

technical field [0001] The invention belongs to a soil physical attribute parameter inversion method based on space-borne passive microwave remote sensing, and specifically relates to a passive microwave remote sensing inversion method for surface soil temperature, surface soil temperature, and surface soil roughness. Background technique [0002] Spaceborne passive microwave remote sensing has large-scale, quasi-all-weather, and quasi-all-weather monitoring capabilities, and has certain penetration capabilities for clouds, rain, and the atmosphere, and has unique advantages in surface soil parameter inversion. In the past ten years, a variety of spaceborne passive microwave radiometers have been launched successively in the world, mainly including the multi-channel scanning microwave radiometer SMMR, the microwave radiometer imager SSM / I, the advanced microwave radiometer AMSR-E and the European Space Agency The L-band SMOS satellite, my country is also stepping up efforts t...

AI Technical Summary

Problems solved by technology

However, the empirical model method has obvious disadvantages: ①The empirical model generally uses the high-frequency microwave band, which is greatly affected by the atmosphere; ②The vegetation index is sensitive to vegetation biomass, and with the increase of the band frequency, the penetration A sharp decrease in penetration

However, this method still has certain deficiencies: ① Most surface soil moisture inversion models are located in areas covered by many vegetation, and their inversion accuracy will be greatly affected. It will cause a 12% inversion error; ② Some studies need to accurately simulate surface parameters such as surface soil temperature, dielectric constant, vegetation extinction coefficient, and surface soil roughness to obtain relatively accurate surface soil moisture data. However, the accurate simulation of surface parameters such as surface soil temperature, dielectric constant, vegetation extinction coefficient, and surface soil roughness is also a scientific issue that needs to be further studied.

However, this method still has certain shortcomings: ①It is not suitable for areas with high vegetation coverage or relatively high humidity; ②The model needs surface parameters such as surface soil temperature, dielectric constant, vegetation extinction coefficient, and surface soil roughness as input parameter

[0008] The use of passive microwave remote sensing to simulate surface soil roughness is seldom, and these studies are basically empirical models and semi-empirical models, and the research is not deep enough.

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