Course 323: RF Interference & Jamming Concerns for GPS & GNSS

Instructors	Mr. Logan Scott, LS Consulting Mr. Phil Ward, Navward GPS Consulting
About This Course	Radio frequency interference (RFI) and jamming are of increasing concern to both military and civil users as GPS and GNSS implementations proceed. This course addresses these concerns by reviewing and analyzing interference and jamming threats and their effects on equipment operation. The instructors address a variety of equipment analysis and design techniques which can be used to mitigate the effects found in adverse environments. One half-day addresses various aspects of GPS integrity and presents an aviation case study. This course is very popular as an on-site course, usually with minor modifications to suit the customer’s applications. Dr. Trent Skidmore and Dr. Stephen Heppe are also available to teach this course on an on-site basis this year.
Prerequisites	Course 122 or an understanding of GPS principles. Familiarity with GPS receiver engineering terms and receiver operations.
Who Should Attend?	Those concerned with the operation or design of equipments for use in jamming or interference conditions, and those concerned with the protection of systems from these effects.
Course Schedule	DAY 1 Mr. *Logan Scott*
	8:30 - Threat Overview and Unintentional RF Interference Signal waveforms, power levels Nominal receiver architectures Functional impact of RF interference [Continuous Wave (CW), noise, pulses] Scope of problem: required C/N₀; emission levels of environmental sources 9:45 - Jamming and Spoofing Threats (Part I) Jamming and spoofing objectives, analysis Receiver performance, break points, countermeasures Effects of broad band noise, pulsed noise, CW and Gold code jammers 11:00 - Jamming and Spoofing Threats (Part II) The role of the internet in advancing the threat Civilian vs. military spoofing Spoofing techniques: GPS signal, differential link, & code contamination Methods for hardening the civil infrastructure against spoofing 12:00 - Lunch on your own 1:30 - Case Studies: (subject to change) Terrorist and Military Scenarios Terrorist jamming attack on civil aviation Cruise missile attack scenario L5 and M-Code vulnerability Galileo vulnerability 2:45 - GPS Interference in Aviation The Mesa Arizona Accidental Jamming Incident LAAS and WAAS Sample CW and wideband interference test results Protecting the data link for LAAS Quantifying the effect of interference Sample test results 4:00 - Land Mobile & Maritime Systems Receiver configurations Broadband effects C/N₀measurements Documented interference examples The Moss Landing EMI incident Summary of Solutions RAIM/FDI and threat signatures IDN and Snaptrack™ External aiding Antenna nulling Multiple antenna phase differences Data authentication 5:00 - Day 1 ends
	DAY 2 Mr. Phil Ward
	8:30 - Overview of Antijam Design Techniques I Jamming and spoofing detection techniques in a GPS receiver Front-end filtering techniques 9:45 - Overview of Antijam Design Techniques II Enhanced GPS tracking techniques, including aiding Narrowband and wideband RFI mitigation techniques Antenna design enhancements 11:00 - Analysis of RFI Effects I Analysis of unjammed GPS signal power Analysis of jamming effects Computation of jamming to signal ratio (J/S) 12:00 - Lunch on your own 1:30 - Analysis of RFI Effects II Analysis of GPS receiver tracking loop thresholds Vector tracking and inertial integration for improved jamming resistance RF interference signal levels 2:45 - Analysis of RFI Effects III Receiver J/S performance - analysis example Computing range to jammer given antenna gain, jammer type and power 4:00 - GPS Receiver Vulnerabilities/Mitigation Approaches Comparison of precorrelation and postcorrelation A/D conversion of GPS receivers C/A code vulnerability to CW RFI Narrow correlator vulnerability to RFI DGPS data link vulnerability to RFI Codeless and semi-codeless GPS receivers' vulnerability to RFI Natural factors that reduce RFI 5:00 - Course ends
Materials You Will Keep	• A notebook with copies of all presentation materials. • NavtechGPS' CD-ROM containing a variety of GPS references.
Continuing Education Units	1.2 (12 hours)
Attendee Quotes	“Clearly the material presented will prove useful on the job. The anti-jam details both in-depth and practical.” - Michael S. Bielas, Raytheon “I will use this information in my work with antenna characterization. These courses were very interesting and provided practical methods for evaluating GPS receivers in test & evaluation.” - W. Mark Henderson, NAWCWD “All the instructors were extremely knowledgeable and very professional.” - Francisco O. Caro, White Sands Missile Range “My job is to simulate the flight at remotely piloted vehicle to targets. Navigation errors (using a coupled INS/GPS) are of utmost importance. This course, along with the last 2 courses I’ve taken, will allow me to do analysis of RFI effects this job intelligently. Will help me find the right fidelity for my simulation effort.” - Frederick Kiefer, Bogdon Associates “I will use this information in the evaluation of system resistance to jamming on UK military helicopters. The most useful session for me was ‘Threat Scenarios’ and ‘Adaptive Arrays’ because my work includes reduction of threats to platforms and protective measures.” - M. R. Alexander, Qinetiq Course 323 critique quotes by military and civil attendees: “The course saved me hours of research, substantiated a design concept, and verified some key parameters and concepts.” “The anti-jamming and RFI material provided good information for simulation work and the detail on every chart was excellent.” “This material will be of great help to me in specifying GPS receiver requirements for my applications.” “The best sessions for me were the threat overview and unintentional RFI - the concepts were very well presented.” “This practical information will help me make practical trade-offs.” “The course helped me better understand the threats & vulnerabilities [of GPS].” Return to top of page