利用激光强度信息分类激光扫描测高数据

Classification of Laser Scanning Altimetry Data Using Laser Intensity

三维机载激光扫描测高数据中不仅含有每个激光脚点的位置和高程信息,而且越来越多的系统同时能提供激光脚点回波信号的强度信息。不同反射面介质对激光信号的反射特性不一样,用实测的数据对激光回波信号的强度信息进行统计标定,并基于标定结果,实现了联合激光强度信息和高程信息进行分类的算法,获得了较为满意的结果。

The airborne laser scanning altimetry data contains the 3D coordinates of the laser footprints and intensity of the return pulse. The amount of light that is returned from a target's surface is characterized by the reflection coefficient. For a diffusely reflecting target, the maximum value of reflection coefficient is 100%. For mirror-like or retro-reflecting targets, the theoretical value of reflectivity can exceed 100% by far. The reflection coefficient is, of course, also depending on the wavelength. For the specified airborne laser scanning altimetry, the intense of the reflectivity varies with the interacted material of the object surface. For materials with skinny or glossy surface, the reflectivity figure represents the maximum light return, with the sensor beam exactly perpendicular to the material surface. Airborne laser scanning altimetry data classification algorithm combined with the intensity of laser is studied in detail. The fusion of height data and intensity data can achieve good classification.