In recent years drones became a real threat to big events, critical infrastructure, but also simply to everybody's privacy. Since the devices are quite small they cannot be detected by the existing air surveillance radar systems. Therefore, a new technology for the detection of drones is required and several new products have been announced in the last few years. Nevertheless, these technologies are still subject to intensive research which will be presented in this short course. In the first part after an overview over the problem also non-radar based technologies (camera, acoustic) will be presented, but the major part of the workshop is dedicated to radar-based drone detection technologies.