D1/2: GPS Interference

Time:
Monday, June 2, 8:30 a.m. - 10:00 a.m.
Monday, June 2, 10:45 a.m. - 12:15 p.m.
Location: Ballroom C

Diverse elements of international infrastructure are critically reliant on GNSS for precise location and time, often in ways that are not obvious. This tutorial provides a high-level perspective on the effects of interference on GNSS receivers and offers some possible threat mitigation approaches and policy recommendations.

The tutorial starts with a discussion of potential GNSS threats and vulnerabilities. Then, after a quick review of how receivers determine position, the focus is on the effects of various interference types on select signals. The effects of ground mobile propagation in limiting effective jammer range are examined. Mitigations such as adaptive arrays, and IMU aiding are discussed.

Civil jamming examples and incidents are covered along with methods to detect, identify, and militate against their effects. In particular, the importance of maintaining situational awareness for establishing environmental context is examined. Techniques for detecting civil spoofing and authenticating signals will be discussed.

Logan Scott has over 40 years of military and civil GPS systems engineering experience. He is a consultant specializing in radio frequency signal processing and waveform design. At Texas Instruments, he pioneered approaches for building high-performance, jamming-resistant digital receivers and adaptive arrays. In 1985, his team built the first all-digital GPS receiver. At Omnipoint (now T-Mobile), he developed spectrum sharing techniques that led to a Pioneer’s preference award from the FCC. Logan has been an active advocate for improved civil GPS location assurance for over 25 years and was the first to describe how civil navigation signals could be authenticated using delayed key concepts central to the Chimera and ACAS signals. For the past seven years he has been developing advanced signal concepts for NTS-3, AFRL, and the University of Colorado. He has also been active in developing LEO system architectures. Logan is a Fellow of the Institute of Navigation and a Senior Member of IEEE. In 2018 he received the GPS World Signals award. He is the author of Interference: Origins, Effects, and Mitigation in PNT21 and in 2022 was awarded the Capt. P.V.H. Weems award for continuing contributions to the art and science of navigation. Logan holds 46 US patents and is a member of the President’s National PNT Advisory Board.