Bidirectional reflection distribution function measurement system based on compact six arm robot

The bidirectional reflectance distribution function (BRDF) is a function that characterizes the reflective properties of a material surface. The measurement of BRDF can effectively analyze the optical properties of target materials and improve the accuracy of remote sensing data. Based on this, a BRDF measurement system is developed, which uses a six arm robot and a stable platform to make the sample to be measured rotate in three dimensions and the light source rotate in one dimension. At the same time, the corresponding host computer software is developed to control the sample to be measured and the light source to reach the required position quickly and accurately, and the geometric conditions required for system measurement can be constructed quickly and conveniently. The system has the ability to measure incident light and reflected light in the range of azimuth 0 ° to 360 ° and zenith angle 0 ° to 80 °. The spectral measurement range is from 200nm to 1100nm. The geometric relationship construction required for each BRDF measurement is completed by the upper computer software, and each construction and measurement takes about 5S. Based on this system, the BRDF parameters of two kinds of onboard calibration plate materials are completed, and the measurement uncertainty is better than 1.9%, which meets the requirements of on orbit calibration of the load.