Multi-Constellation GNSS Integrity Check for Detection of Time Signal Manipulation
First Claim
1. A time distribution device for receiving and distributing a time signal, comprising:
- a Global Navigation Satellite System (GNSS) receiver suitable for receiving a first time signal from a first GNSS constellation and receiving a second time signal from a second GNSS constellation;
a time quality module configured to;
receive the first and second time signals from the GNSS receiver;
calculate a phase error between the first and second time signals; and
detect manipulation of one of the first and second signals using the phase error; and
a time output for distributing a time signal to a receiving device.
2 Assignments
0 Petitions
Accused Products
Abstract
The present application discloses detecting manipulation of GNSS signals using a second time source. If two or more GNSS constellation signals are being detected, the phase error between the GNSS constellation signals may be monitored. When the phase error drifts, then manipulation is determined. The integrity of a GNSS constellation signal may be monitored using an internal time source such as a crystal oscillator by monitoring a slope of the free running counter at the detected rising edges of a pulse-per-second signal from the GNSS constellation. If more than two GNSS constellations are monitored, a voting scheme may be used to determine the manipulated GNSS constellation.
33 Citations
19 Claims
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1. A time distribution device for receiving and distributing a time signal, comprising:
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a Global Navigation Satellite System (GNSS) receiver suitable for receiving a first time signal from a first GNSS constellation and receiving a second time signal from a second GNSS constellation; a time quality module configured to; receive the first and second time signals from the GNSS receiver; calculate a phase error between the first and second time signals; and detect manipulation of one of the first and second signals using the phase error; and a time output for distributing a time signal to a receiving device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for receiving and distributing a time signal, comprising:
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a time distribution device receiving a first time signal from a first Global Navigation Satellite System (GNSS) constellation; the time distribution device receiving a second time signal from a second GNSS constellation; calculating a phase error between the first and second time signals; detecting manipulation of one of the first and second time signals using the phase error; and distributing a time signal to a receiving device. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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19. A time distribution device for receiving and distributing a time signal, comprising:
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a Global Navigation Satellite System (GNSS) receiver suitable for receiving a first time signal from a first GNSS constellation and receiving a second time signal from a second GNSS constellation; a time quality module configured to; receive the first and second time signals from the GNSS receiver; determine a phase error between the first and second time signals; and detect manipulation of one of the first and second signals using the phase error by comparing the determined phase error with a manipulation threshold and finding manipulation in response to the phase error exceeding the manipulation threshold; and a time output for distributing a time signal to a receiving device.
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Specification