  This work is devoted to the problem of distributed target tracking when a
team of robots detect the target through a variable perception-latency
mechanism. A reference for the robots to track is constructed in terms of a
desired formation around the estimation of the target position. However, it is
noted that due to the perception-latency, classical estimation techniques have
smoothness issues which prevent asymptotic stability for the formation control.
We propose a near-optimal smooth-output estimator which circumvents this issue.
Moreover, local estimations are fused using novel dynamic consensus techniques.
The advantages of the proposal as well as a comparison with a non-smooth
optimal alternative are discussed through simulation examples.
