Active electro-optical lasers for surface and air targets

This report summarizes and discusses results from tests with active laser-based electrooptical systems aimed at small surface targets at sea level and at air targets at low altitude, respectively. As part of an international collaboration, comparisons have also been performed between the active lidar systems and other types of electro-optical sensor technologies. The purpose of the report is to create an understanding about system capabilities and limitations, as well as the probable future development of technology in this area. Thus, a contribution is made to the discussion about how systems of this type can be utilized within the framework of future military sensor assets. The conclusions for surface targets are largely based on exploitation of data collected during tests conducted in November 2014. The FOI tests were performed in collaboration with the research organizations Dstl (GB) and Fraunhofer IOSB (DE). Simulations have also been performed and verified in order to complement the experimental test results. The main focus of the report is on surface targets, but low-altitude airborne targets are also discussed, because the latter are similar the former with respect to detection and classification techniques. These similarities justify a parallel analysis of these two types of targets. Therefore, we also report on results from tests with different laserbased methods against a mockup of a cruise missile at a distance of 1.3 km. The trials show that laser profiling techniques can be used to classify small surface targets (length below 10 meters) according to type up to a target distance of 7 km. Calculations, however, indicate a potential range well beyond this distance, especially if the current detectors are replaced by photon counting hardware. Active laser are versatile sensor systems with a multitude of different uses besides obtaining a target profile or imaging the target. Hence, the report also discusses the alternative use of the system for atmospheric lidar measurements. We consider this versatility central to future cost-effective realization of high performance optical systems.