A lower bound for passive sensor-network auto-localization

In this paper a lower-bound for estimation of inter-sensor propagation delay using sources of opportunity is presented. This approach is referred to as passive identification. It relies on Ward identity, which is extended to the case of non white sources. Performances are studied in the case of an homogeneous non dispersive linear and time invariant wave propagation medium, under the assumption that many independent sources impige on the sensor array.