Terrestrial laser scanning is a ground-based version of the airborne LIDAR frequently used for terrain and landscape mapping. Terrestrial laser scanners are a relatively recent development for high-resolution mapping. These scanners, originally developed for as-built modeling of architectural and engineering structures, can also be used for high-resolution mapping of terrain, vegetation, and other landscape features over limited distances in the range of 50–300 m. Like their airborne counterparts, these are active sensors that emit laser signals to calculate distances based on the time delay of the returned laser pulses.