In fact

the Doppler measurement containing information of target velocity has the potential capability of improving the tracking performance.Two filters are proposed which can use converted Doppler measurements (i.e.the product of the range measurements and Doppler measurements) in the Cartesian coordinates.One filter uses the Doppler pseudo-states;another doesn't use the Doppler pseudo-states.These novel filters are theoretically optimal in the rule of the best linear unbiased estimation in the Cartesian coordinates

and they are free from the fundamental limitations of the measurement-conversion approach.Based on simulation experiments

the approximate

recursive implementations of these two novel filters are compared with those obtained by five state-of-the-art conversion techniques recently.Simulation results demonstrate the effectiveness of the proposed two filters.