See around corners with radar - Annual report 2007

Authors:

  • Stefan Nilsson
  • Magnus Gustafsson
  • Anna Jänis
  • Ain Sume
  • Anders Örbom

Publish date: 2008-01-07

Report number: FOI-R--2357--SE

Pages: 49

Written in: Swedish

Keywords:

  • See-around-corners
  • radar
  • Doppler radar
  • diffraction
  • reflection
  • urban
  • environment

Abstract

This annual report summarises the activities in the first year and presents the most interesting results of the three-year strategic research project "Radar for detection of human activity around corners". The aim of the project is a technical evaluation of the idea of using the bending of radar waves (diffraction) around corners and/or their reflection in opposite building walls to detect moving objects off the line-of-sight. Both methods present the advantage of keeping the sensor system and the soldier hidden from the enemy and hence diminish the risk of detection and elimination. In a literature search conducted, no clear-cut work was found that aimed at "see-aroundcorner" applications, but most references treated mainly communication applications in urban environment. The FOI work in the area is hence of a pioneering nature. At the Lilla Gåra test range, measurements were carried out in the year of a Doppler source positioned off the line-of-sight. In the idealised measurements metallic walls were used together with a Doppler source in circular motion. The very promising results show that the Doppler signal can be detected, both with diffracted and reflected fields. A basic measurement was made of the reflexion properties of various types of facing material as a function of polarisation, frequency, and angle of incidence. The strength of the diffracted field has been calculated at various positions in the shadow region of the wall, the results showing it being sufficient for detection of moving objects with an adapted radar system.