Direction Finding for Radio Transmitters With Mini Interferometric Network

In this paper, we present the design and deployment of a broadband interferometric mini array. The network with five electromagnetic signal detectors deployed over an area about 1 km² is applied here to record 20- to 70-kHz vertical electric fields emitted by radio transmitters in very low frequency/low-frequency band. Furthermore, interferometric imaging algorithm is employed to evaluate the elevation angles and azimuth angles of the electromagnetic radiation source. It is found that the deviation between expected azimuth and the mean value of calculated azimuth is less than 0.2° with standard deviation of 3.55°. The experiment results indicate that the mini array may provide benefits in determining the precise locations of electromagnetic radiation sources.