LIDAR (Light Detection an 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 instead of light, 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 in archaeology, geography, geology, geomorphology, seismology, remote sensing and atmospheric physics.Other terms for LIDAR include ALSM (Airborne Laser Swath Mapping) and laser altimetry. 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.