DTM generation in forested area using multiple return pulses from airborne laser scanner

摘要

Airborne laser scanner is widely adopted for city modeling, DTM (Digital Terrain Model) generation, monitoring electrical power lines and detection of forest areas. In generally, airborne laser scanning enables to acquire point cloud 3D data for surface of the ground or objects using multiple return pulses (first, last and other pulse). Filtering for distinguish on- and off-terrain points from point cloud 3D data which are collected by airborne laser scanner was issue, and various filtering methods have been developing for generating DTM using point cloud 3D data.rnWaveform information (range, pulse amplitude, pulse width) which is corrected by resent laser scanner system has been receiving more attention for improvement of classifying the point cloud data into on- and off-terrain points. Waveform information has ability to classify the point cloud data, however, robust filtering for distinguish on- and off-terrain points is still issue. The main problem is robust extraction of the deepest points which shows ground surface. As many filtering and classifying methods for robust extraction of the deepest points were proposed including waveform information, the problem reaches extraction of the last pulse since the last pulse show the deepest points.rnWith this motive, filtering and classifying approach for DTM generation in forested area using multiple return pulses instead of waveform information are investigated in this paper.