Patent ID: 8089393
Filing Date: 2012-01-03
Classification: G01S

Abstract:
1. A method of tracking a target at a local node in a decentralised network having a plurality of nodes, each node comprising a processor, a sensor operable to make target observations, communication means operable to transmit and receive track information, and storage means operable to store track information at the local node, the method comprising: in the processor of each node: (i) associating each initial model probability of a set of initial model probabilities with a target dynamics model of a set of target dynamics models, wherein each initial model probability is related to a probability that target dynamics are in accordance with an associated target dynamics model; (ii) associating each initial model target state estimate of a set of initial model target state estimates with the target dynamic model of the set of target dynamics models; (iii) calculating a set of predicted model target state estimates by applying each target dynamics model to an associated initial model target state estimate; (iv) in response to a target observation being made at the local node, performing a first tracking procedure, thereby updating track information stored at the local node; (v) in response to track information being received at the local node from a remote node, performing a second target tracking procedure, thereby updating track information stored at the local node; and (vi) communicating updated track information to selected other nodes in the network; and wherein the first tracking procedure comprises the steps of: (a) calculating updated model probabilities in dependence on a difference between the target observation and the predicted model target state estimate; (b) calculating updated model target state estimates in dependence on the predicted model target state estimate and the target observation; and (c) calculating a composite predicted target state estimate by combining the predicted model target state estimates using a weighting related to the updated model probabilities; and the second tracking procedure comprises the step of conservatively fusing the received track information with track information stored at the local node to produce fused track information; and wherein the track information comprises one or more of: the updated composite target state estimate, the updated model target state estimates, and the updated model probabilities.