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US 9,958,549 B2Granted
Methods and apparatus for detecting spoofing of global navigation satellite system signals using carrier phase measurements and known antenna motions
AssigneeCornell University
InventorsMark L. Psiaki, Steven P. Powell, Brady W. O'Hanlon
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Abstract
Methods and systems that can detect GNSS spoofing attacks and that do not require explicit or implicit knowledge of exact position or attitude and that provide hypothesis test statistics, threshold values, and probabilities of false alarm and missed detection.
Claims31
A method for determining whether a GNSS (Global Navigation Satellite System) receiver has been spoofed, the method comprising:
- moving, using an articulation subsystem and a location displacement component, a receiving location in a predetermined articulation pattern while receiving GNSS signals at the GNSS receiver;
- high pass filtering, using a spoofing detection hypothesis test component, carrier phase measurements of received GNSS signals and the predetermined articulation pattern;
- the high pass filtering resulting in estimation of coefficients in an expression for carrier phase measurement residuals;
- determining, using the spoofing detection hypothesis test component, a likelihood cost function minimum for a non-spoofed configuration;
- a likelihood cost function being obtained from a ratio of probability density functions;
- results of the high pass filtering being used in determining said likelihood cost function;
- determining, using the spoofing detection hypothesis test component, a minimum for another likelihood cost function for a spoofed configuration;
- a spoofing detection hypothesis test statistic being a difference of said another likelihood cost function minimum and said likelihood cost function minimum;
- results of the high pass filtering being used in determining said another likelihood cost function;
- and
- comparing, using the spoofing detection hypothesis test component, the spoofing detection hypothesis test statistic to a predetermined threshold;
- the GNSS signals deemed to be spoofed if the spoofing detection hypothesis test statistic is less than the predetermined threshold.
9 more elements
A system for determining whether a GNSS (Global Navigation Satellite System) receiver has been spoofed, the system comprising:
- a receiving location displacement component configured to move a receiving location with respect to a position at which the user equipment processes GNSS signals;
- an articulation subsystem configured to provide driving signals to the receiving location displacement component and to determine receiving location articulation;
- the articulation subsystem moving a receiving location in a predetermined articulation pattern while receiving GNSS signals;
- a number of midpoint sampler subsystems, each midpoint sampler subsystem receiving input from a component of one channel of a conventional GNSS receiver and providing a beat carrier phase measurement for that one channel;
- and
- a spoofing detection hypothesis test component receiving:
- location articulation, and
- said beat carrier phase measurement for each one channel and a PLL phase error discriminator value for said each one channel, said beat carrier phase measurement and said PLL phase error discriminator value for said each one channel being used to obtain a wideband estimate of beat carrier phase for said each one channel, a number of accumulation mid point times, each accumulation mid point time being an accumulation mid point time for one channel, and a number of unit direction vectors, each unit direction vector pointing from a GNSS signal source for one channel;
- said spoofing detection hypothesis test component configured to:
- high pass filter the wideband estimate of beat carrier phase and the receiving location articulation for said each one channel;
- the high pass filtering resulting in estimation of coefficients in an expression for a wideband estimate of beat carrier phase residuals;
- determine a likelihood cost function minimum for a non-spoofed configuration;
- a likelihood cost function being obtained from a ratio of probability density functions;
- results of the high pass filtering being used in determining said likelihood cost function;
- determine a minimum for another likelihood cost function for a spoofed configuration;
- a spoofing detection hypothesis test statistic being a difference of said another likelihood cost function minimum and said likelihood cost function minimum;
- results of the high pass filtering being used in determining said another likelihood cost function minimum;
- and
- compare the spoofing detection hypothesis test statistic to a predetermined threshold;
- the GNSS signals deemed to be spoofed if the spoofing detection hypothesis test statistic is less than the predetermined threshold.
17 more elements
Dependencies are inferred from the claim text.