Doppler signatures of radar backscattering from objects with micro-motions

Radar backscattering from objects with micro-motions is subject to Doppler modulations that help determine dynamic properties of objects and provide useful information about the objects. Doppler modulations represented by joint time–frequency analysis provide useful time-varying Doppler characteristics and, thus, add additional time-dimension information to exploit motion characteristics. The author discusses how to simulate radar backscattering from objects with rigid body motions and objects with non-rigid body motions, and how to analyse, interpret and characterise Doppler signatures of objects that undergo these micro-motions. Precession heavy top and human locomotion are used as examples of rigid and non-rigid body motions, respectively. Radar micro-Doppler signatures derived from these motions illustrate the potential of the joint time–frequency analysis for exploiting kinetic and dynamic properties of objects.