1. A method of tracking target objects in a network of unidirectional sensors which correspond to nodes on the network, the method comprising identifying the presence of a target object by a first unidirectional sensor, determining a first value for the relationship of the target object to the first unidirectional sensor, sending a message to at least one second unidirectional sensor which is a neighbor to the first unidirectional sensor, the message including a unique identification of the target object and the first value, monitoring messages from at least one second unidirectional sensor sending a second value indicative of the relationship of the target object to the at least one second unidirectional sensor, ranking the first value and second value, if available, and the first unidirectional sensor utilizing the ranking of the first and second criterion to determine whether to elect itself the head of a cluster including at least the first unidirectional sensor or join a cluster headed by a second unidirectional sensor, and propagating the cluster by dropping a sensor from the cluster when the target object gets out of the sight of the sensor.