Detection of and risk of giving away position with active laser systems

Military use of lasers is becoming more and more common. Questions about the risks of discovery when using lasers, and how enemy lasers can be detected, are therefore relevant. After a review of different types of military laser systems, sensor systems and atmospheric effects, some conclusions are given for different situations. There are two situations where the use of lasers causes a great risk of giving away your position. The first is when illuminating a platform equipped with a laser warning system with pulsed lasers. The second is long illumination times with lasers at wavelengths shorter than 900 nm that can be discovered with night vision devices. Other use of lasers is not without risk, but discovery basically demands that the position is already under surveillance. To detect that a platform is illuminated, laser warning devices are the only method that gives high probability of detection and autonomous operation. A SWIR-camera can then be used to determine the exact position of the illuminating laser, especially for laser designators. As the radiation is scattered at large angles by the optics of the laser the camera does not need to be close to the illuminated platform, the scattered radiation can be detected at tens of degrees from the laser beam. With an imaging detector there is a small, but not negligible, possibility to detect enemy laser usage. To realize what is illuminating the sensor at short exposure to laser radiation it may be important to have experienced how a laser looks with the sensor.