Download
1 / 28
350 likes | 659 Views
Evaluation of the Effect of Global Positioning System (GPS) Simplistic Spoofing Attacks on GPS Performance. Introduction. Increasing use for PNT applications: Positioning Navigation Timing . GNSS Vulnerabilities. Ionospheric delay Tropospheric delay Satellite clock error Ephemeris error
E N D
Evaluation of the Effect of Global Positioning System (GPS) Simplistic Spoofing Attacks on GPS Performance
Introduction Increasing use for PNT applications: • Positioning • Navigation • Timing
GNSS Vulnerabilities • Ionospheric delay • Tropospheric delay • Satellite clock error • Ephemeris error • Signal error • LOS blockage • Receiver noise • Dilution of precision • Jamming • Spoofing
Forging and transmission of navigation messages in order to manipulate the navigation solutions of GNSS receivers Even if a spoofer is not fully successful, he/she can still create significant errors and jam GNSS signals over large areas GNSS Spoofing
GPS spoofing used to trick a British vessel into Chinese waters GNSS Spoofing
A number of GNSS simulators have been designed for legal purposes In the wrong hands, can be used for spoofing GNSS Spoofing
GNSS simulators can be built with relatively low cost equipment GNSS Spoofing
The spoofing threat continuum GNSS Spoofing
Meaconing GNSS Spoofing • GNSS record and playback systems record real GNSS signals and retransmit the signals to evaluated GNSS receivers. • While spoofing using this method cannot be used to impose user-defined scenarios on a receiver, it can still cause the receiver to compute false location fixes using the transmitted real GNSS signals. • Furthermore, this form of attack can be used for spoofing military GNSS signals
Objectives • This study is aimed at evaluating GPS performance during simplistic GPS spoofing attacks. • Spoofing is conducted using a standalone GPS simulator, which at present poses the greatest near-term threat. • In this type of spoofing attack, the spoofing signal is not synchronised (in terms of power level, phase, Doppler shift and data content) with the genuine signals received by the target GPS receiver. • This could cause the target GPS receiver to temporarily lose position fix lock first, before being taken over by the spoofing signal.
Methodology Test Setup Test area located at N 2º 58.056’ E 101º 48.586’ 70m
Methodology Test Scenario • Test area located at N 2º 58.056’ E 101º 48.586’ 70m • The spoofing signal is set for position of N 2º 58’ E 101º 48’ 80m, while the time is set at the simulator’s GPS receiver’s time.
Results & Discussion The effect of GPS spoofing attacks Evaluated GPS receiver Reference GPS receiver
Results & Discussion The effect of spoofing on GPS accuracy Evaluated GPS receiver Reading 2 Reading 3 Reading 1 Reading 5 Reading 6 Reading 4
Results & Discussion The effect of spoofing on GPS accuracy Reference GPS receiver Reading 2 Reading 3 Reading 1 Reading 5 Reading 6 Reading 4
GPS Spoofing The effect of spoofing on GPS accuracy Evaluated GPS receiver Reference GPS receiver
Conclusion • Varying minimum spoofing signal power levels, times between position fix lost and spoofing, and probable error patterns are observed for different dates and times. • This is due to the GPS satellite constellation being dynamic, causing varying GPS satellite geometry over time, resulting in GPS performance being time dependent. • Variation in other GNSS error parameters, including ionospheric and tropospheric delays, satellite clock, ephemeris and multipath errors, and unintentional signal interferences and obstructions, could have also resulted in the variation of GPS performance. • As the spoofing signal power level is increased, probable error values increase due to decreasing C/N0levels for GPS satellites tracked by the receiver. • For all the readings, the highest probable errors occur at the minimum spoofing power levels. After spoofing takes place, the probable errors reduce to levels that are lower as compared to prior to transmission of the spoofing signal. • This occurs as at this point, the spoofing signal power level is relatively large, resulting in high C/N0 level and hence, improved accuracy.
Scope for Future Work • On the whole, this study has demonstrated the disadvantages of field GNSS evaluations. • Without the ability to control the various GNSS error parameters, it is difficult to effectively study the effect of any particular error parameter, in the case of this study, spoofing, on GNSS accuracy. • This highlights the importance of conducting such tests in a controlled environment, using a GNSS simulator as the source of genuine GNSS signals as opposed to live GNSS signals. • This would allow the tests to be conducted under repeatable user-controlled conditions.
GNSS Receiver Evaluation GNSS Simulation Field Evaluation • Employs live GNSS signals. • Should be conducted in open area with clear view of the sky. • Tests scenarios are uncontrollable by users and not repeatable. • Employs simulated GNSS signals. • Should be conducted in a RF enclosure (e.g. anechoic chamber). • Test scenarios are user controllable and repeatable.
GPS Jamming Field Evaluation GPS Simulation
GPS Functional Tests Pendulum Instruments GPS-12R Trimble Geoexplorer 6000 GeoXH, Nomad 900G and Juno SB Magellan Z-Max Topcon Hiper GA Trimble R8 ProMark 200
Research Collaborations • Effect of Radio Frequency Interference (RFI) on Global Positioning System (GPS) Static Observations • Collaboration with Faculty of Architecture, Planning and Surveying (FSPU), Universiti Teknologi MARA (UiTM) • Project Co-Leaders: • Assoc. Prof. Sr. Dr. Azman Mohd Suldi • Mr. Ahmad Norhisyam Idris
