www.microwavejournal.com/articles/30129-introduction-into-theory-of-direction-finding

Introduction into Theory of Direction Finding
April 13, 2018
There is a growing requirement for determining the location of emitters in radiomonitoring, security services, military intelligence, etc. Spectral components used in spread-spectrum techniques can only be allocated to a specific emitter if the direction is known. Direction finding is therefore an indispensable first step in radiodetection.