Laser rangefinders (LRFs) are used by drones and unmanned systems to determine the distance to a particular target or object of interest. They typically calculate distance via the time-of-flight principle, which measures the time taken for a pulse to be reflected from a distant object, or by measuring the phase shift of reflected light at multiple frequencies.
UAV rangefinders can be used for a variety of unmanned vehicle applications, and are often incorporated into drone gimbals along with cameras to aid in applications such as surveying, asset inspection and military reconnaissance. They may also be used in conjunction with thermal cameras to measure the distance to fires. Some rangefinders can be integrated with GNSS/GPS and GIS data capture for precise mapping.
In addition, LRF can also be used to aid unmanned vehicle flight and navigation. Altitude measurement by a downwards-pointing laser rangefinder is useful for precision takeoff and landing, as well as terrain-following and distance-keeping. Different surfaces and materials provide different levels of laser absorption and reflection, so laser rangefinders that measure the strength of the reflected beam can be used to determine when UAVs are flying over particular surfaces such as ice.
Rangefinder technology can also provide information for self-driving vehicles, as well as mapping systems that use SLAM (simultaneous localization and mapping) to navigate indoors and in GPS-denied environments such as underground caves and mines.