A method for estimating soil moisture from fy-3c passive microwave data

Abstract

The invention discloses a method for estimating soil humidity based on FY-3C passive microwave data. The method makes full use of the multi-polarization characteristic of passive microwave characteristic brightness temperature data, the number of equations is increased, meanwhile comprehensive consideration of the influence of vegetation optical thickness and surface roughness on the brightness temperature on stars is made, the number of unknowns is decreased, the existing problem that the emissivity of a roughened surface and the vegetation optical thickness are needed to be known to estimate the soil humidity in the prior art is solved, and soil humidity estimation based on the brightness temperature data on the FY-3C satellite passive microwave stars is achieved.

Description

technical field [0001] The invention relates to a quantitative remote sensing technology, in particular to a method for estimating soil moisture from FY-3C passive microwave data. Background technique [0002] The water on the earth is composed of ocean water, terrestrial water and atmospheric water, and each component of water plays an important role in global environmental changes. Among them, although soil moisture only accounts for 0.005% of the total water volume of the earth, it has a very important influence on the interaction between the hydrosphere, biosphere and atmosphere, and is an important part of the global water cycle. Soil moisture is a key parameter that reflects the state of soil moisture. Understanding and obtaining large-scale, long-term soil moisture distribution and changes is very important for studying and solving problems faced by global change, agriculture, ecology, hydrology, and the environment. Significance. Traditional soil moisture observati...

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Problems solved by technology

Traditional soil moisture observation methods can only obtain soil moisture data at limited observation points, and the observation results can only reflect the soil moisture conditions in the surrounding areas of the observation points, so the spatial representation is poor, and the long-term soil moisture data acquired by traditional methods are limited. higher cost

Therefore, it cannot meet the current needs of agriculture, ecology, environment, etc.

[0003] The main disadvantages of existing soil moisture estimation methods based on microwave radiation transfer theory are: the algorithm is relatively complex, and it is difficult to obtain the surface state parameters that need to be directly input (such as rough surface emissivity and vegetation optical thickness). In the calculation process, more other surface parameters (such as vegetation water content) are needed, and the error is large, which leads to the great limitation of these soil moisture estimation methods in practical application.

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