Mitigation Paths for Free-Space GPS Jamming

he designed and implemented instrumentation for energetic materials testing and atmospheric physics research. Matt has been a member of the GPS/INS Systems Section since 1989, and has been involved with design and implementation of missile hardware-in-the-loop simulations, navigation error analysis and GPS jamming efforts. He is currently tasked in the development and analysis of GPS jammer systems. Kenea Maraffio received her BS in Electrical Engineering from Arizona State University. Employed by NAWCWPNS, China Lake, in 1991, she worked on development of phased-array antenna control software and radome compensation algorithms. In 1993 Kenea developed software for real-time remote control of the Stanford Telecom 7200 GPS satellite simulator. Kenea is currently developing software for remotely controlling a smart, free-space GPS jammer. ABSTRACT Many modern weapon systems depend on Global Positioning System (GPS) to achieve midcourse or terminal accuracy requirements. This reliance on GPS navigation dictates that weapon system test facilities be equipped to create realistic GPS jamming (GPSJ) environments. The Naval Air Warfare Center Weapons Division (NAWCWPNS) at China Lake is developing a system of free-space jammers to create a realistic GPS threat environment. The goal of this effort is to yield a high-degree of commonality among outdoor jamming systems and the ones used in NAWCWPNS' Navigation Laboratory and anechoic facilities. The ability to successfully conduct free-space GPS jamming tests in the continental US is highly problematic due to extensive civilian use of GPS. This paper begins by discussing the major issue related to conducting free-space GPS jamming tests: interference with commercial and other DoD GPS users. Following this discussion, the paper focuses on proposed mitigation methods modeled after NAWCWPNS' energetic materials testing process. The paper concludes with an analysis of a scenario based on an example free-space GPS jammer.