Rapid digital elevation data capture using airborne scanning lasers: recent projects in the U.S.A. Europe and South Africa

摘要

Abstract: In recent years, the use of airborne scanning laser technology has been rapidly increasing. Many governmental as well as private organizations around the world are evaluating this nascent technology as an advanced means of digital elevation data collection. These organizations have been working in conjunction with Optech of Toronto, Canada to conduct demonstrations and experiments as part of a rigorous examination of the capabilities and accuracy of Optech's Airborne Laser Terrain Mapper (ALTM). This paper will present examples of recent projects conducted in the United States, Europe and South Africa along with a brief description of the fundamental concepts inherent to the technology and its operation in different environmental settings. In certain circumstances where traditional survey techniques such as aerial photogrammetry or standard terrestrial methods are impractical or impossible, often an airborne scanning laser survey is more economical and productive. Also, since no ambient light is required, airborne scanning laser systems can operate day or night. Some of the areas in which the use of this technology may be more beneficial include: forest floor mapping, power wire detection, corridor or route surveys, large topographic surveys and mining. An additional application of airborne scanning laser devices is in the measurement of power line proximity to vegetation. Among the varied applications of airborne scanning lasers, forested areas are of particular interest because they are problematic for companies employing traditional remote sensing methods. Unlike photogrammetry, scanning laser systems can actually penetrate the forest canopy and accurately measure the terrain and objects below. !4