DISTRIBUTED TRACKING IN MULTI-HOP NETWORKS

We describe distributed tracking of a linear dynami-cal system via networked sensors. The networked sen-sors communicate with each other by means of a multi-hop protocol over a communication network. MMSE-optimal solution is Kalman filtering when measure-ments are available centrally, but new methods are re-quired to account for communication constraints. We derive optimal algorithms to deal with arbitrary net-work topology and then extend these results to account for communication delays and packet losses. The pro-posed techniques differ from related techniques pro-posed in two important aspects: a) there is no desig-nated leader/fusion node and each sensor attempts to optimally track the system trajectory based on its local observations and time-dependent information available from other sensors in the network; b) the message com-putation at each sensor is structurally identical, where the computed message from each sensor is the inno-vation in the state conditioned on all the information available upto that time at each sensor. Consequently, the sensor network can be queried at any time and at any node to obtain optimal estimates for the state of the dynamical system. 1