The measurement and modeling investigation on the BRDF of brass under variable temperature

•A measuring method considering the thermal radiation was proposed to measure BRDF under variable temperature in the near-infrared region.•The influence of heating time on BRDF of brass surface was analyzed in detail.•A six-parameter model of BRDF was built according to material surface characteristics. The measurement of BRDF in near-infrared under variable temperature is conducive to the investigation of the scattering characteristics of material surfaces and its application in related fields. However, the previous studies on BRDF measurement mostly focus on the room temperature target, and the work under variable temperature is rarely reported. In this paper, the BRDF of the rough brass surface in the near-infrared band under variable temperature is measured with a modified device. The absolute measuring method considering thermal radiation is adopted to improve the accuracy and reliability of the measurement. The results indicate that the temperature, heating time and surface roughness have significant effects on BRDF. The source of measuring error is analyzed in detail, and the overall error is not higher than 3.29%. In addition, a six-parameter model of BRDF is built according to material surface characteristics. The fitting results show that the calculated values are in good agreement with the measured values at different temperature.