激光强度值会受到大气环境、激光测距值、目标物特性等因素的影响,同类目标物的激光强度值产生较大的偏差。为了消除扫描距离对地面扫描激光强度的影响,以激光雷达测距方程为基础,设计了同种材料、不同距离与点云反射强度的实验,通过实验得出了激光扫描距离与点云激光强度之间的变化关系和数学模型,并将实验数据修正效果较好的模型(如泰勒插值多项式模型、分段多项式模型、分段高斯函数与多项式混合模型)用于实例点云激光强度的修正,结果显示,泰勒插值多项式模型修正效果最好,可以有效地消除距离因素引起的点云强度偏差,使同类目标的激光强度趋于一致,异类目标的激光强度差异明显。

Laser intensity is affected by factors such as atmospheric environment, scanning distance, target characteristics, thus the laser intensity values of the similar targets have a large deviation. In order to eliminate the impact of the scanning distance on the intensity of terrestrial laser scanning, based on Lidar ranging equation, experiments with the same material, different distance, and reflection intensity of point cloud, are designed. The relationship between the laser scanning distance and the laser intensity of point cloud and the mathematical model are obtained. The models with better experimental data correction effects (including Taylor interpolation polynomial model, Sectional polynomial model, Section al Gaussian function, and polynomial mixed model) are used to modify the laser intensity of the point cloud. The results show that the Taylor interpolation polynomial model has the best correction performance, which effectively eliminates the deviation of point cloud intensity caused by the distance factor, and makes the laser intensity of the same kind of target tend to be consistent, and the laser intensity difference of heterogeneous targets is obvious.