Abstract
The problem of tracking multiple targets with passive electronic or sonar sensors requires at least three sensors for correct measurement-target association. Mathematically, the measurement -target association problem leads to a generalization of the multi-dimensional assignment problem, which is known to be NP-complete when the number of sensors S /spl ges/ 3, i.e., the complexity of an optimal algorithm increases exponentially with the size of the problem. We consider a three sensor case and solve the 3-dimensional assignment problem using a Lagrangian relaxation algorithm that successively solves a series of generalized two-dimensional assignment subproblems with the worst case complexity of O(k n/sup 3/), where n is the number of reports from each sensor, and k is the number of dual iterations. This paper investigates the computational efficiency of three recently developed assignment algorithms - RELAX II, generalized Auction and generalized Signature methods --- as part of the dual relaxation method. The computational efficiency of the algorithms is evaluated for various target spacing/sensor accuracy ratios, false alarm and missed detection probabilities. It is concluded that the generalized Auction is 4-5 times faster than either RELAX-II or the generalized signature method.