Harmonic Radar for Differentiating Between Friend and Foe

We present a modified harmonic radar architecture for distinguishing between two dynamic targets - a friend and a foe - in the radar propagation channel. The main application for our proposed radar is for search and rescue missions or surveillance. The radar consists of a narrowband sinusoidal transmitter and a dual channel receiver, wherein the primary and secondary channels are tuned to the fundamental transmitted frequency and its second order harmonic respectively. The radar scattered returns from both friend and foe are gathered at the primary receiver while the secondary receiver gathers the second order harmonics emanating from the harmonic radar tag on the friend. The secondary receiver data are used to train unique data driven dictionaries that characterize the motion of the friend. These dictionaries are used to disaggregate and reconstruct the returns from the friend and foe in the primary linear radar data. We validate our proposed radar concept on simulated radar data of a friend and foe and demonstrate that the radar signatures from the reconstructed radar data are qualitatively and quantitatively similar to the ground truth radar signatures from the friend and foe.