Adaptive beams for beamspace direction finding

Radio direction finding in the high-frequency band is challenging since the complex signal and noise environment is difficult to model, defeating the basis of most high-resolution techniques. Since fixed beams are ineffective with the small apertures common at HF, the authors propose a method for designing beams adaptively (i.e., in a data-dependent manner). Results based on both simulation and real HF field data show that adaptive-beamspace processing can be superior to either element-space or fixed-beamspace processing