The probabilistic data association filter (PDAF) is a statistical approach to the problem of plot association in a radar tracker, in which all of the potential candidates for association to a track are combined in a single statistically most probable update, taking account of the statistical distribution of the track errors and clutter and assuming that only one of the candidates is a target, and the rest are false alarms. An extension of the PDAF is the Joint Probabilistic Association Filter which takes account of the situation where more than one of the potential candidates represents an actual target.