Streit, R. L., Graham, M. L., and Walsh, M. J., Multitarget Tracking of Distributed Targets Using Histogram-PMHT, Digital Signal Processing 12 (2002) 394–404 The expectation-maximization method is applied to derive a stable tracking algorithm that uses the entire display (image) as its input data, completely avoiding peak picking and other data compression steps required to produce traditional point measurements. The algorithm links a histogram interpretation of the intensity data with the tracking method of probabilistic multihypothesis tracking (PMHT) and is thus referred to as H-PMHT. An example of H-PMHT applied to tracking in bearing on a passive sonar broadband display is provided.