Method and Realization of Calculating BRDF System with Multi\|angle Images

BRDF(Binomial Distribution Function) can describe the reflection characteristics of the surface，one of the cutting\|edge hot issues in multi-angle research in quantitative remote sensing.In order to study the reflection of the objects at different angles of observation，the measurement data are obtained by using the aerial photogrammetry method.Based on the collinear equation and semi-empirical core-driven model theory，the measurement of BRDF system with Multi\|angle Image is realized by using C# object\|oriented programming，including SFM(Struct From Motion) algorithm to solve camera parameters and establishment of the image pyramid to read image data efficiently and accurately.The system polarized graph were generated by selecting soil and maize ground point in the multispectral image data obtained by using the Micro\|MCA six-channel multi\|spectral camera，compared and analyzed with the image of the BRDF simulation software(DART).The results show that the system is computationally efficient and robust.The reflectivity of any observation angle extrapolated from the core driving model is in accordance with the characteristics of BRDF.The “hot spot” appears at the same side observation of the sun，which is consistent with the change trend of reflectivity of DART simulation image.The multi\|scale module designed in the system can meet the calculation requirements under different spatial resolution of image.The realization of the system provides a reference for the follow\|up study of multi\|angle measurement of BRDF in quantitative remote sensing.