Method for establishing bidirectional reflectance distribution function (BRDF) prototype library based on multi-angular measurement

Abstract

The invention relates to a method for establishing a bidirectional reflectance distribution function (BRDF) prototype library based on multi-angular measurement. Through self-defining bidirectional anisotropic flat index (AFX) and iterative self-organizing ISODATA clustering algorithm, a theory and a method for establishing the BRDF prototype library based on BRDF feature mode are provided and are realized by using 69 groups of ground surface multi-angular measurement data and the history data (MCD43A) of global EOS ground surface verification core point. According to the theory and the method, the conventional method for establishing a BRDF database based on the ecological form of ground surface is abandoned, the BRDF prototype library is different from the global pixel-to-pixel BRDF database of MODIS (Moderate-resolution Imaging Spectroradiometer) in the service operation at present; and is small in volume, simple and convenient to construct and easy to operate, and is applicable for other airborne and spaceborne multi-angular measurement data of ground surface. In the technical field of spatial information, the method particularly has theoretical and application values for extracting BRDF prior knowledge to invert ground surface parameters in the aspect of quantitative remote sensing.

Description

1. Technical Field [0001] The invention relates to a method for constructing a bidirectional reflection distribution function (BRDF) prototype library based on multi-angle measurement, and belongs to the technical field of spatial information. 2. Background technology [0002] The anisotropic reflection on the earth's surface is the basic macroscopic phenomenon of the reflection of electromagnetic waves by objects in nature. The study of the surface bidirectional reflection distribution function (BRDF) is an important part of the field of optical quantitative remote sensing. Since the 1970s, satellite remote sensing has mainly adopted vertical observation methods to obtain biophysical parameters of the surface vegetation canopy. With the development of remote sensing technology, in-depth research on the interaction mechanism between vegetation and light radiation, as well as various new demands, people are increasingly aware that multi-angle remote sensing provides additional inf...

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Problems solved by technology

[0003] At present, in constructing the dichroic reflectance database based on multi-angle observation data, the change law of the dichroic reflectance of the surface ecology is usually obtained by merging the surface ecological types. The variance between classes, which brings great difficulties to the application of the method on a global scale

Currently, MODIS uses a pixel-to-pixel global BRDF database, which is based on high-quality historical data accumulation, but the problems in constructing such a database are: (1) The assumptions are not fully established, that is, it is necessary to assume that the same period in different years The change of BRDF is stable and consistent, and the high-quality BRDF data of the same period can be obtained through years of data accumulation and filling; (2) It is difficult to obtain global complete multi-angle data, that is, even if this assumption is true, in the equatorial region and high Due to the influence of clouds and solar zenith angles, it is difficult to obtain high-quality BRDF data; (3) the amount of data is huge, that is, the BRDF database generated by this method usually has hundreds of GB and cannot obtain the basic changes of BRDF law

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