All laser rangefinders, laser altimeters and LIDAR units are derived from the early colidar systems. It was originally called 'Colidar' an acronym for 'coherent light detecting and ranging', derived from the term ' radar', itself an acronym for 'radio detection and ranging'.

Intended for satellite tracking, this system combined laser-focused imaging with the ability to calculate distances by measuring the time for a signal to return using appropriate sensors and data acquisition electronics. Under the direction of Malcolm Stitch, the Hughes Aircraft Company introduced the first LIDAR-like system in 1961, shortly after the invention of the laser. It has also been increasingly used in control and navigation for autonomous cars and for the helicopter Ingenuity on its record-setting flights over the terrain of Mars. It is used to make digital 3-D representations of areas on the Earth's surface and ocean bottom of the intertidal and near coastal zone by varying the wavelength of light.

Lidar is commonly used to make high-resolution maps, with applications in surveying, geodesy, geomatics, archaeology, geography, geology, geomorphology, seismology, forestry, atmospheric physics, laser guidance, airborne laser swathe mapping (ALSM), and laser altimetry. LIDAR has terrestrial, airborne, and mobile applications. LIDAR may operate in a fixed direction (e.g., vertical) or it may scan multiple directions, in which case it is known as LIDAR scanning or 3D laser scanning, a special combination of 3-D scanning and laser scanning. Lidar ( / ˈ l aɪ d ɑːr/, also LIDAR, LiDAR or LADAR, an acronym of 'light detection and ranging' or 'laser imaging, detection, and ranging' ) is a method for determining ranges by targeting an object or a surface with a laser and measuring the time for the reflected light to return to the receiver. Vegetation heights are depicted in shades of green, where dark greens are closest to the ground and light greens are the highest. For ground-level features, colours range from deep brown to tan.

This visualisation shows an airplane collecting a 50 km swathe of LIDAR data over the Brazilian rainforest.

Big city map gmod