Secondary surveillance radar (SSR) is the radar technology used in aviation to query transponders; it forms the backbone of today’s air traffic control infrastructure. Our guest in this episode is Mike Sharples who has been part of the development of the technology and is intimately familiar with the details. We discuss the importance of SSR today, the details of the protocol, the difference between and evolution from Mode A/C to S as well as the relationship to ADS-B.
In this episode we look back at (aspects of) the North American Air Defense system in the cold war. In particular, we look at the distant early warning line(s), the F-106 interceptor and the SAGE computer system. For DEW, we talk with Mike Milinkovich and Brian Jeffrey who have both worked on the DEW line; Brian also maintains a great website on DEW. For the F-106, we talk with Richard Embry who has flown the interceptor. And for SAGE, we speak with Bernd Ulmann, who has written a very detailed book on SAGE’s underlying AN/FSQ-7 computer system. Bernd has also been a previous guest on Episode 159 on analog computers.