VHF/UHF Emitter Localization Based on DOA Fusion with Two UAS

I-Fusion presents a emitter localization technique based on the fusion of DOA obtained at two flying small UAS. Each UAS is equipped with a nonlinear smart antenna system for signal detection and DOA estimation and a GPS receiver for time synchronization and UAS localization. The whole desired frequency band is scanned using hierarchical coarse and fine searching method to maintain the scanning speed and low power consumption. The DOA estimation uses a hierarchical (coarse and fine) delay and sum (DAS) searching method. For the alignment of the two DOA from the two UAS, the DOA is marked with time tag and the signal"s spectrum signature is also extracted. The DOA with time tag, the corresponding signal"s spectrum signature and the UAS position are transmitted to the ground control station through the control channel, where the DOA coming from the two UAS are aligned based on the time tag and spectrum signature and then fused to localize the emitter. The proposed localization system covers the VHF and UHF push to talk radio and cordless phone frequency. It only cost 615mW, weights 148g and its size is 70mm(L)50mm(W)18mm(D).