Radio Direction Finding and Superresolution [Hardcover]

Enlarged and revised second edition. Modern direction finders, capable of measuring elevation angles as well as azimuth angles on the components of multi-ray wavefields, have become powerful tools for research in ionospheric physics and HF radio propagation. The complexity of the problem of resolving closely-spaced rays requires the combined use of wide aperture antenna arrays, multichannel receiving systems and sophisticated digital processing techniques.