In order to study the scattering characteristics of practical machining surfaces under the infrared laser irradiation, an experiment device is designed to measure the semispherical scattering characteristics of machining surfaces. The measuring system consists of a laser power meter with a resolution of 10 nW, a laser device of 1550 nm wavelength, and two precisely rotating platforms. The distributions of scattering power from the specimen surfaces with micro V-groove structures and different surface roughness values are measured under the irradiation of 1550 nm infrared laser. After the measured results are converted into the bidirectional reflectance distributional function, the effects of incident azimuthal angle, incident angle, and surface roughness on the scattering characteristics of surface of such a kind are comparatively analyzed, and the cause for the formation of special scattering field is also analyzed. The experimental results indicate that the surface texture, incident angle and surface roughness all affect the scattering property in a regular manner. The results contribute to the study of surface scattering characteristics and the application of laser technology to surfaces with V-groove structures.

There are two kinds of methods to measure the bidirectional reflectance distribution function (BRDF), direct method and relatively method. The relatively method is widely used because of its convenience and small error. However, the BRDF of the Spectralon white reflectance standard in relatively method was found to deviate from the Lambertian BRDF. It was found to vary with the angle of incidence, the wavelength of incidence and the states of polarization of the incident and reflected light. This paper proposes an optimized measurement formula of BRDF. The result is corrected. Taking the BRDF of standard roughness specimens for example, experimental results show that the measurement accuracy is improved comparing with the original formula. Finally the error analysis is carried out on the accuracy of measurement. The research has certain reference significance for the study of target characteristics on noncooperative target ranging.