Laser based sensor concepts for UAV

Two areas of technology that have seen rapid developments during the last years are unmanned aerial vehicles (UAV) and laser sensors for 3D imaging or ladar (laser detection and ranging). It is natural to combine these technologies by using an UAV as a sensor platform for a ladar. This report contains an overview of different ladar technologies that could be used in air-to-ground applications. Two promising concepts have been identified. An UAV of size similar to AAI Shadow 200, designated "Örnen" in Sweden, could be equipped with a ladar system for large scale reconnaissance, information gathering and mapping. Two possible sensor types are a downscaled version of the scanning ladar systems used for mapping from manned platforms today, or the use of systems based on photon counting array detectors, a technology already in use by the US military e.g. for mapping of Afghanistan from larger platforms. The second promising concept is to mount a rotating multiline scanning ladar on a multi-rotor UAV. These sensors have ranges of 20-100 m and could provide a rapid situational awareness or record an incident. For imaging the lateral resolution is limited by the limited focal length of collection optics that is possible on an UAV and the large pixels on 3D sensor arrays. In some cases threat identification may thus be better served by 2D laser illuminated active imaging, where sensor pixels can be smaller and identification thus easier.