Soil moisture monitoring microwave radiometer method

Abstract

The present invention relates to the application of microwave remote sensing technology, and is especially microwave radiometer method of monitoring soil moisture. The method includes the following steps: 1. preparing operation environment and radiometer data; 2. inverting to obtain field surface dielectric constant of the observed point and forming grids; 3. calculating the soil moisture based on the dielectric constant; and 4. mapping soil moisture distribution and saving as common graph format.

Description

technical field [0001] The invention is used in the application field of microwave remote sensing technology, in particular to a method for retrieving soil moisture by using microwave radiometer data. Background technique [0002] In the existing method of using microwave radiometer to invert the surface soil moisture, when calculating the opacity of the surface vegetation layer, auxiliary data about the classification of the surface vegetation type and the water content of the vegetation layer are needed. The calculation formula is: [0003] τ c =b*ω / cosθ [0004] where b is a parameter related to the vegetation canopy structure and frequency, ω is the water content of the vegetation layer, and θ is the observation angle. Both b and ω need to be obtained through auxiliary data. However, in practical applications, these auxiliary data are often difficult to obtain or unreliable, and even if this part of the data is obtained, the application is more complicated (eg figure...

AI Technical Summary

Problems solved by technology

[0005] The biggest problem existing in the calculation of the opacity of the vegetation layer in the existing technology is that it is difficult to obtain and update the auxiliary data in time, and only empirical values ​​can be substituted into the calculation, and the time synchronization between the auxiliary data and the observation data of the microwave radiometer cannot be guaranteed.

For example, the parameter b is determined according to the ground vegetation classification data, but in practice this parameter will change with the vegetation growth, and there are differences in this value when observed at different frequencies; ω as the water content of the vegetation layer will change with the Changes with seasons and precipitation

Both the b and ω values ​​in the empirical calculation formula have time and climate variability, and using fixed values ​​to describe the opacity of the vegetation layer during radiometer observation cannot fully reflect the influence of vegetation on the surface radiation at the time of radiometer observation

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