Nonlinear modeling of gated range tracker dynamics with application to radar range resolution

Nonlinear dynamic models for gated radar range trackers are developed and applied to the range resolution problem. Two common types of tracking loop dynamics, as well as the automatic gain control, are accounted for in the models. The null detector is formulated in a general way that encompasses many important error detector laws, including centroid and leading edge. For a deterministic target return condition, general criteria for asymptotic stability of equilibrium points are obtained. The most striking of the stability criteria is a sign requirement on the slope of a range error curve. These criteria are used in a two-target example to draw conclusions on a tracker´s ability to resolve closely spaced targets as a function of target separation. These conclusions are compared with previously reported conclusions on resolvability obtained by using Woodward´s `ambiguity function´ approach