BRDF normalizing correction method for airborne push-broom hyperspectral image of forest region

Abstract

The invention provides a BRDF (bidirectional reflectance distribution function) normalizing correction method for the airborne push-broom hyperspectral image of a forest region having an accidented relief. The method comprises the following steps: calculating the plane-based sun-observation geometry of the pixels of the image by using the observation view field and flight attitude information of an airborne push-broom hyperspectral device and the sun position at a data acquisition moment, extracting the slope and aspect information of the corresponding pixels based on high-precision DEM (digital elevation model) data, rotating the plane-based sun-observation geometry of the pixels to true sun-observation geometry, extracting the pixels of every surface feature from classified image data, forming a multi-angle observation reflectivity data set, and constructing a BRDF model according to the true sun-observation geometry; and normalizing the multi-angle direction reflectivity in the image to the reflectivity at an assigned observation-sun angle by adopting a multiplicative normalization factor. The method can effectively correct the BRDF effect of the airborne push-broom hyperspectral image of the forest region having the accidented relief, and is of great significance to the quantitative study of subsequent images.

Description

technical field [0001] The invention relates to the field of forestry informatization, in particular to a binomial reflectance distribution function (BRDF) normalization correction method for airborne push-broom hyperspectral images in forest areas with undulating terrain. Background technique [0002] Since the 1970s, the application of remote sensing technology has greatly improved people's ability to detect ground objects and has conditions for in-depth quantitative analysis. The anisotropic reflection of ground objects is one of the macroscopic phenomena in nature, and its specific performance is that its surface reflection changes with the change of the incident radiation direction and the observation angle. The multi-angle observation phenomenon of ground objects will cause radiation distortion, which restricts the accurate description of the inherent reflection properties of ground objects. It is an important part in the field of quantitative remote sensing to carry ...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the problem that the existing BRDF correction algorithm cannot be based on the imaging characteristics of the airborne push-broom hyperspectral equipment and the radiation correction in the complex imaging environment of the forest area with undulating terrain

The new multi-angle data set will satisfy the existing BRDF correction algorithm, thus solving the binomial reflectance distribution function (BRDF) correction problem of airborne push-broom hyperspectral imagery in forested areas with undulating terrain

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