Investigation of light scattering properties based on the modified Li-Liang BRDF model

Light scattering property is an important indicator for the laser remote sensing applications. Targets surface features can be extracted from the intensity data through the light scattering property and the exploitation of laser intensity for a more effective target characterization has become a topic of interest. However, there isn’t an universal scattering model i. e. bidirectional reflectance distribution function (BRDF) to describe the multiple targets’ scattering properties and the surface features cannot be represented by the same types of parameters of a particular BRDF. In this paper, a modified Li-Liang BRDF model is proposed by adding the directional diffuse reflection to the Li-Liang BRDF model, to our best knowledge, it is the most suitable for describing a series of materials’ scattering properties with dual-wavelength (532 nm and 1064 nm) than other BRDF models. Based on which, a theoretical evaluation method of Gm-APD detection performance is proposed which can be used to find the optimal LiDAR system parameters. Through evaluation, to effectively detect 3 km building target, the transmitting energy is at least 10.29 μJ for 1064 nm laser, it is at least 80.7 μJ for 532 nm laser. The incident angle is a significant factor affecting the detection probability, and 1064 nm wavelength is a better choice for single-wavelength detection; however, the intensity of 532 nm transmitted laser should be relatively higher for the dual-wavelength detection. This paper offered a typical method for choosing LiDAR system parameter based on the accurate scattering properties.