Radar for surveillance, Status report

Authors:

  • Stefan Nilsson
  • Thord Andersson
  • Åsa Andersson
  • Magnus Gustavsson
  • Tommy Johansson
  • Mikael Karlsson

Publish date: 2017-04-26

Report number: FOI-R--4419--SE

Pages: 26

Written in: Swedish

Keywords:

  • Doppler radar
  • “see behind corners”
  • “see-through-the-wall”
  • wall penetrating radar
  • polarization
  • urban scenario
  • battlefield surveillance
  • MIMO
  • NLOS

Abstract

This progress report describes the activities carried out, and the results produced in the second year of the three-year Swedish Armed Forces sponsored project Radar for Surveillance. The project involves further development of the competence and technology platform established through previous efforts in the research areas of Wall Penetrating Radar and Radar for Seeing behind Corners. The project is focused on developing methods and system solutions primarily for Doppler radar system designed for urban environments. The project investigates how a network of small, simple radar sensors should be designed for autonomous detection, positioning and tracking of moving threats in complex environments. The performance of such MIMO radar system was studied for an urban scenario including a flying UAV. Given the radar parameters of the individual sensors, the capability of the radar network to position and track the drone in free space is calculated. The simulation results shows that the radar network implies a significantly enhanced performance compared to the individual sensors. The next step is to study how multipath contribution can be utilized. The FOI-introduced method of using radar to detect moving objects behind the corner has been studied further. A successful field trial has demonstrated the ability to detect a UAV hidden behind a wall via only multipath reflections. The Doppler signature of its rotors could be sensed even after the radar wave have undergone up to six wall reflections. These results open the possibility to classify UAVs in difficult complex environments. In simulations our developed system concept for positioning moving objects behind corners shows promising results. This or similar concepts, should be studied further, aiming at a mobile system solution where the radar is placed on a moving vehicle. In order to assess a mobile see-behindcorner system, simulations have been carried out. The main objective of these simulations was to examine if it is possible to handle the environmental clutter in the Doppler spectrum caused by the motion of the radar. A potential clutter compensation method has been identified. During the year, two international surveys have been performed. The first is a literature study focused on multipath propagation in complex environment. The second survey focused on identifying experimental investigation of micro-Doppler signature of UAVs. International cooperation is carried out by participation in the NATO group Advancing Sensing Through the Walls Technologies. The group studies new improved methods to detect, track and image people behind walls. Results from the joint trial in Ottawa in 2013 with various wallpenetrating systems, will be reported in the final report which will be published next year.