Range-Doppler surface: a tool to analyse human target in ultra-wideband radar

A novel concept, called range-Doppler surface (RDS), for human target analysis using ultra-wideband radar is proposed. The construction of RDS involves range-Doppler (RD) imaging, adaptive threshold detection and isosurface extraction. A Keystone-transform-based range migration compensation approach is proposed to allow high-quality RD imaging using ultra-wideband radar. Adaptive threshold detection is applied to detect the extended target in the RD image, and RDS is constructed by extracting an isosurface from a RD video sequence, which is defined as a sequence of RD images. In comparison with micro-Doppler profiles and high-resolution range profiles, RDS contains range, Doppler and time information simultaneously. An ellipsoid-based human motion model is designed for validation. RDSs simulated for different human activities are demonstrated and discussed. Finally, experimental results for single/two-people walking scenarios are presented to verify the simulation results. The use of the RDS opens a new area of human target analysis.