Three Dimensional Velocity Measurement Using a Dual Axis Millimeter-Wave Interferometric Radar
Abstract
In this work, a method for directly measuring target velocity in three dimensions using a dual axis correlation interferometric radar is presented. Recent advances have shown that the measurement of a target's angular velocity is possible by correlating the signals measured at spatially diverse aperture locations. By utilizing multiple orthogonal baselines and using conventional Doppler velocity methods to obtain radial velocity, a full three-dimensional velocity vector can be obtained using only three receive antennas and a single transmitter, without the need for tracking. A 41.8 GHz dual axis interferometric radar with a 7.26λ antenna baseline is presented along with measurements of a target moving parallel to the plane of the radar array, and of a target moving with components of both radial and tangential velocity. These experiments achieved total velocity root-mean-square errors of 41.01 mm·s-1 (10.5\%) for a target moving along a plane parallel to the array, and 45.07 mm·s-1 (13.5\%) for a target moving with components of radial and tangential motion relative to the array; estimated trajectory angle RMSEs of 10.42 and 5.11 were achieved for each experiment respectively.