Within a project funded by the Italian Aerospace Research Centre UAV program, the Department of Aerospace Engineering at the University of Naples is in charge of developing an obstacle detection and tracking system aimed at non-cooperative collision avoidance. In this framework, a flight prototype of an autonomous Detect Sense and Avoid system has been installed onboard a Very Light Aircraft for evaluating performance in flight tests. The system is based on multiple-sensor data integration and it includes several components, such as a Ka-band pulsed radar, four Electro Optical sensors and two processing units. This paper is focused on the description of an indoor facility for hardware-in-the-loop tests which was realized to maximize the out...