An Introduction to Direction Finding

Radio direction finding, also called radiolocation, is the process by which a source of radio frequency energy is localized. Direction finding plays an increasingly important role in many civilian, government, and military applications, including areas such as interference hunting, search and rescue, (counter)intelligence, and localization of uncooperative sources. This presentation begins with a general overview of radio direction finding and radio direction finding principles, and then moves on to a discussion of the different methodologies which can be used to determine the physical location of an RF energy source. The radio direction finding methodologies covered in this presentation include (1) manual direction finding and homing, (2) Doppler, (3) power / angle of arrival, (4) Watson-Watt, (5) correlative interferometry, and (6) time difference of arrival. For each of these methodologies, a brief technical introduction is followed by a discussion of that methodology’s relative strengths and weaknesses, appropriate applications, and the areas in which a given methodology is most commonly employed. Examples of how these technologies are implemented, primarily in civilian applications, will also be provided. Throughout the presentation, emphasis is placed on the real-world applications of each of these direction-finding methods, with discussions supported by actual examples of how these methodologies are being used in field applications.

Presenter Bio:

Paul Denisowski is an Product Management Engineer at Rohde & Schwarz North America, where he specializes in radiomonitoring, radiolocation (direction finding), and interference hunting solutions, as well as general purpose test and measurement instrumentation. A frequent author and presenter on a wide variety of topics, he has over 20 years of field application experience, including extensive work in direction finding and interference hunting for commercial and military/government customers. Paul previously held field and research positions with HP/Agilent, Fujitsu, Alcatel, and Nortel, and has both a Master's degree in Electrical Engineering from North Carolina State University as well as a Master’s degree in Germanic Languages from UNC-Chapel Hill. He was also a visiting lecturer at the Tokyo Institute of Technology under a joint grant from the US National Science Foundation and the Japanese Ministry of Education and has been an active amateur radio operator (KO4LZ) for almost three decades.