Microwave interferometric and Doppler radar measurements of a UAV

The first dual-mode measurements of the time-varying radial and angular velocity signatures of a UAV quadcopter are presented. Measured with a compact 24 GHz interferometric radar, the signatures are measured at various observation angles relative to the UAV. It is shown that the signatures from the UAV at high grazing angles, when the radial velocity of the rotor blades relative to the radar is low, provide features related to the rotation rate of the rotor blades in certain instances. Using both Doppler and interferometric radar velocity measurements may therefore provide a method of detecting and classifying UAVs.