Active direction finding in imaging sensor nets

We consider herein the problem of active direction finding in imaging the massively scalable sensor networks in which the active sensor nodes reflect electronically the beacon transmitted by a collector node. Very large number of randomly deployed sensor nodes with limited computational capability have no knowledge of their locations, while the location estimation is accomplished by the collector node. The collector node is equipped with noncoherent collections of coherent subarrays at the transmit and receive arrays to achieve both the coherent gain and spatial diversity simultaneously. In this configuration, the transmit and receive spatial diversity can be jointly or independently exploited. The performance of the proposed scheme is validated by the simulation results.