Airborne laser scanning - an introduction and overview

This tutorial paper gives an introduction and overview of various topics re lated to airborne laser scanning (ALS)as used to measure range to and refle ctance of objects on the earth surface. After a short introduction, the bas ic principles of laser, the two main classes, i.e., pulse and continuous-wa ve lasers, and relations with respect to time-of-flight, range, resolution, and precision are presented. The main laser components and the role of the laser wavelength, including eye safety considerations, are explained. Diff erent scanning mechanisms and the integration of laser with GPS and INS for position and orientation determination are presented. The data processing chain for producing digital terrain and surface models is outlined. Finally , a short overview of applications is given. (C) 1999 Elsevier Science B.V. All rights reserved.