An improved single-point track initiation using GMTI measurements

A ground moving target indicator (GMTI) radar measures range, azimuth, and Doppler or range-rate of a target. The range-rate measurement, which is the key measurement of a GMTI radar, is used to differentiate a ground moving target from clutter when the radial velocity of the target exceeds the minimum detectable velocity (MDV). The range and azimuth measurements provide an accurate estimate of the target position. A number of track initiation algorithms using GMTI measurements are known at present. All track initiation algorithms set the initial velocity to zero and a large prior covariance for velocity is used based on the maximum target speed. The range-rate measurement is then used to update the target velocity or state. The range-rate measurement contains only the component of the target velocity along the radar line-of-sight (RLOS) and no component of velocity in the perpendicular direction is measured. As a result, existing track initiation algorithms produce a bias in the velocity estimate. This paper first corrects two errors in the single-point (SP) track initialization part of the paper [29] using the range-rate measurement to obtain the initial velocity estimate and associated covariance. Secondly, we present an improved track initiation algorithm based on a heading-parameterized multiple model (HPMM) method that uses the sign of the range-rate measurement, prior knowledge of target maximum speed, and MDV. The proposed algorithm reduces the bias in the initial velocity estimate and the superior performance of the algorithm is demonstrated using Monte Carlo simulations.