02-04-2011, 11:41 AM
ABSTRACT
Light Detection and Ranging (LIDAR) have recently become the technologies of choice in mass production of Digital Elevation Models (DEMs), Digital Terrain Models (DTMs), and Triangulated Irregular Networks (TINs), referred to generically hereafter as DEMs. This paper presents lessons learned from LIDAR projects to date in various states. It addresses opportunities presented by LIDAR for generating DEMs as articulated by various user groups in the National Height Modernization Study. Finally, it summarizes actions required by the remote sensing community to establish LIDAR as standard tools, with established standards, for generating digital elevation data for the new millennium.
INTRODUCTION
LIDAR (Light Detection and Ranging) is an optical remote sensing technology that measures properties of scattered light to find range and/or other information of a distant target. The prevalent method to determine distance to an object or surface is to use laser pulses. Like the similar radar technology, which uses radio waves, the range to an object is determined by measuring the time delay between transmission of a pulse and detection of the reflected signal. LIDAR technology has application geometrics, archaeology, geography, geology, geomorphology, seismology,forestry, remote sensing and atmospheric physics.[1] Applications of LIDAR include ALSM (Airborne Laser Swath Mapping), laser altimetry or LIDAR Contour Mapping. The acronym LADAR (Laser Detection and Ranging) is often used in military contexts. The term laser radar is also in use but is misleading because it uses laser light and not the radiowaves that are the basis of conventional radar.
