基于多项式模型的TLS激光强度值改正

TLS Laser Intensity Correction Based on Polynomial Model

从激光雷达测距方程出发,根据扫描仪的辐射机制,运用多项式模型拟合激光强度值与接收功率之间的关系。由于系统参数与目标反射率未知,接收功率无法获取,所以通过激光入射角的余弦与激光测距值平方的组合,构造新变量,实现目标反射率与扫描几何因素的分离,根据多项式模型建立激光强度值与新变量之间的模型关系。定义了标准测距值与标准入射角,分析残差特性,对激光强度中的距离和入射角效应进行改正。通过实验进行验证分析。实验结果表明:该方法能有效地去除由距离和入射角引起的强度偏差,精确地对激光强度值进行改正。

Starting from the laser radar range equation, the polynomial model is adopted to fit the relationship between the laser intensity value and the received power based on the instrumental radiometric mechanism.Because of the unknown system parameters and target reflectance, it is impossible to compute the definite received laser power. So, by constructing the new variable constituted by the combination of the cosine of the incidence angle and the square of the range, the scanning geometry factors and target reflectance are separated and the polynomial model is used to fit the relationship between the laser intensity and the new variable. The standard range and the standard incidence angle are defined, and the intensity biases caused by the range and the incidence angle are corrected by analyzing. Experiments are conducted to test and verify the proposed method. Results show that the method can effectively remove the variations and biases caused by the range and incidence angle as well as accurately obtain the corrected laser intensity value proportional to the reflectance of the scanned point.