Micro-Motion Signatures in Radar Angular Velocity Measurements

An analysis of the micro-motion signatures in interferometric angular velocity measurements of walking humans is given, and comparisons are drawn to micro-Doppler measurements of the radial velocity of walking humans. It is shown that the interferometric radar signal is mathematically similar to that of a Doppler radar, and that the time-frequency responses of both modes to a walking human show similar characteristics. Simulations of both detection modes are shown, separating out the signatures of the torso, arms, and legs, and comparing the time-frequency signatures of the responses for both the interferometric and Doppler radars. Along with a comparison of the peak signal responses for the various body parts, it is shown that the resulting time-frequency micro-motion signatures are similar for both detection modes, indicating the potential for using developed micro-Doppler classification algorithms for interferometric angular velocity signal classification. Challenges to implementing the interferometric measurement are described, including non-linear processing effects and wide-angle frequency scaling, and recently published potential solutions to these challenges are discussed.