Direction Finding: Analog and Digital Applications (ePoster)

Amateur radio encompasses the building of hardware, the programming of different communications devices, and the integration of hardware and software. One popular amateur pastime, radio direction finding, requires a fair amount of technical knowledge to include antenna design and radio wave propagation in the VHF radio band. Participants use specialized directional antennas to find a bearing for an unknown signal. An intense understanding of antenna radiation patterns can be used to accurately identify the source of this signal. Simulation on computer programs through test equipment helps hobbyists fully understand the characteristics of their direction finding devices. However, direction finding can be approached from the electronic realm as well as the physical realm. Instead of just directional antennas, one can utilize Digital Signal Processing (DSP) with software‐defined radios to locate and identify unknown signals. Programs such as Matlab and GNURadio combined with hardware such as the KerberosSDR and HackRF fully utilize this avenue of signals intelligence. The dichotomy between “physical” direction finding and digital signal processing provides an interesting argument for use of one over another. While antenna‐focused direction finding relies on vast technical knowledge of propagation and gain, computer‐ based direction finding similarly requires computational knowledge with various signals and mathematical techniques. In addition, the two techniques serve almost divided purposes: while analog direction finding can locate a signal real‐time, DSP can be used to deconstruct and decode signals after their interception. One technique does not outweigh the other, as both have different use cases and applicability. This presentation will outline the basic approach to each avenue of direction finding and the advantages each technique holds. Hobbyists should learn from both techniques of direction finding to gain applicable skills in electromagnetic wave theory.