UAS-based microwave and millimeter-wave imaging sensor technologies for various security-related applications

Abstract

Since many decades satellites and aircraft are preferred platforms to monitor our environment with a variety of sensors systems. In the last ten to fifteen years, un-piloted Unmanned Aerial Systems (UAS) or drones have flooded the market as a quite cheap and powerful new type of platform, further increasing the broadness of applications considerably. The DLR Microwaves and Radar Institute is doing massive research on imaging sensors in the microwave (MW) and millimeter-wave (MMW) domain for all kind of previously described platform types. The following three actual developments for security applications will be discussed in detail. In the project HAPSAR, an S-band SAR system is currently developed for a High-Altitude Platform (HAP) operating in 20 km altitude and to be flown in a few years on the present DLR platform development HAP-alpha. The UHF-band SAR system Dronar is a sensor tool for surface and buried object detection (e.g. landmines), being implemented on a rather small Quadcopter for safe and efficient investigation of hazardous areas from distances of about 5-15 m. The multi-sensor system Downvision-Alpha is combining an MMW imaging radiometer and an MMW imaging radar for helicopter pilot assistance during critical maneuvers, like landing approach, from few hundred meters altitude down to few meters distance.