Existing detection systems generally are operated using a fixed threshold a
nd optimized to the Neyman-Pearson criterion. An alternative is Bayes detec
tion, in which the threshold varies according to the ratio of prior probabi
lities, In a recursive target tracker such as the probabilistic data associ
ation filter (PDAF), such priors are available in the Form of a predicted l
ocation and associated covariance; however, the information is not at prese
nt made available to the detector. Put another way, in a standard detection
/tracking implementation, information flows only one way: from detector to
tracker. Here, we explore the idea of two-way information flow, in which th
e tracker instructs the detector where to look for a target, and the detect
or returns what it has found, More specifically, we show that the Bayesian
detection threshold is lowered in the vicinity of the predicted measurement
, and we explain the appropriate modification to the PDAF, The implementati
on is simple, and the performance is remarkably good.