A distributed positioning algorithm for cooperative active and passive sensors

Paper in proceedings, 2010

The problem of positioning of an unknown target in cooperative active and passive wireless sensor network is addressed. Two-way time of arrival and time difference of arrival measurements in active and passive nodes are used to estimate the position of the target. A maximum likelihood estimator (MLE) can be employed to solve the problem. Due to nonlinear nature of the cost function in the MLE, the iterative search might converge to local minima resulting in large error of estimation. To avoid the MLE drawback, we formulate the problem of positioning as the intersection of some convex sets. To nd the position estimate, we apply projection onto convex sets approach which is robust and can be implemented in a distributed manner. Simulations are performed to compare the performance of the MLE and new method.