Spectrum Localization and Hough Transform-Based β Tuning for LSS Targets’ Accurate Micro-Doppler Imaging System

In this work, we present the accurate micro-Doppler (m-D) imaging of behaviors of simultaneous operation of multiple low-altitude, smaller size, and slowly flying (LSS) targets. A
$C$
-band (5.3 GHz) continuous-wave (CW) radar is indigenously designed and used to acquire the m-D signatures. A new spectrum localization and Hough transform-based bandwidth (
$\beta $
) tuning algorithm is proposed to generate accurate time–frequency (T-F) images based on the acquired LSS targets’ nonstationary, linear, nonlinear, rotational, translational, and orbital-/oscillatory-motion multicomponent m-D signatures. In order to practically validate this claim, several realistic open-field experiments are conducted operating four different LSS targets: 1) a flapping bionic bird; 2) three-blades and 3) two-blades rotational systems; and 4) a cone-like translational system, at different ranges in front of the developed radar. The results associated with these experiments and the findings are reported and analyzed.