A general approach for altitude estimation and mitigation of slant range errors on target tracking using 2D radars

When target tracking using polar (azimuth and slant range only) measurements is performed, the most usual approach is to simply ignore slant range errors and perform target position estimation on a 2D plane. In reality, slant range errors are very significant and can seriously impair tracking. 3D target tracking can mitigate the effect of slant range errors, and, in some cases, even allow altitude to be estimated. This paper analyzes previous approaches on 3D target tracking using 2D radars and their drawbacks, and proposes efficient methods (based on EKF, UKF and AMM-EKF) that can be used on realistic scenarios, without significant increase on computational cost. A robust filter initialization technique is also proposed for these methods.