Concrete Arrows, Course Lights, and Navigation Beacons

摘要

Some years ago, I wrote an article on the wider history of navigation systems for this magazine (RadioUser, June 2015: 48-52). In it, I examined those radio navigation systems that were no longer with us, including Loran, Shoran, Consol, Decca, and especially maritime Non-Directional Beacons (NDBs). In some ways, this is a follow up to that article, based on some more historical research, and on information about NDBs that I have subsequently come across.