Detection of moving objects around corners, with no direct line-of-sight to the objects, is demonstrated in experiments using
a coherent test-range radar. A setting was built up on the test-range ground consisting of two perpendicular wall sections
forming a corner, with an opposite wall, intended to mimic a street scenario on a reduced scale. Two different wall materials
were used, viz. light concrete and metallic walls. The latter choice served as reference, with elimination of transmission
through the walls, e.g. facilitating comparison with theoretical calculations. Standard radar reflectors were used as one kind
of target objects, in horizontal, circular movement, produced by a turntable. A human formed a second target, both walking
and at standstill with micro-Doppler movements of body parts. The radar signal was produced by frequency stepping of a
gated CW (Continuous Wave) waveform over a bandwidth of 2 or 4 GHz, between 8.5 and 12.5 GHz. Standard Doppler
signal processing has been applied, consisting of a double FFT. The first of these produced "range profiles", on which the
second FFT was applied for specific range gates, which resulted in Doppler frequency spectra, used for the detection. The
reference reflectors as well as the human could be detected in this scenario. The target detections were achieved both in the
wave component having undergone specular reflection in the opposite wall (strongest) as well as the diffracted component
around the corner. Time-frequency analysis using Short Time Fourier Transform technique brought out micro-Doppler
components in the signature of a walking human.
These experiments have been complemented with theoretical field calculations and separate reflection measurements of
common building materials.