Patent ID: 11926345
Assignee: RAYTHEON SYSTEMS LIMITED
Field: Measurement (Instruments)
Classification: CPC B  G | IPC B  G

Claim 7:
8. An apparatus comprising:
a navigation receiver configured to identify a location of a vehicle and to output the identified location;
wherein the navigation receiver comprises:
a multi-element antenna comprising a plurality of antenna elements;
a plurality of channel receivers, each antenna element of the plurality of antenna elements electrically coupled to a different channel receiver of the plurality of channel receivers, the plurality of channel receivers configured to pre-process a plurality of navigation signals received by the antenna elements;
a plurality of phase detectors electrically coupled to the plurality of channel receivers and configured to identify phases of the plurality of navigation signals;
a plurality of amplitude and phase adjusters electrically coupled to the plurality of phase detectors;
at least one processor electrically coupled to the plurality of phase detectors and to the plurality of amplitude and phase adjusters; and
at least one memory coupled to the at least one processor;

wherein the at least one processor is configured to:
receive information about expected or actual positions of a plurality of satellites associated with the navigation signals, the information about the expected or actual positions of the plurality of satellites comprising a navigation almanac stored in the at least one memory;
determine an angle of arrival for each of the navigation signals by analyzing the identified phases from the phase detectors to identify a time difference of arrival for each of the navigation signals;
identify whether any of the navigation signals received by the navigation receiver are spoofed based on the angles of arrival for the navigation signals; and
suppress any of the navigation signals determined to be spoofed;

wherein, to identify whether any of the navigation signals are spoofed, the at least one processor is configured to:
determine whether more than two of the navigation signals were received at substantially the same angle of arrival;
in response to determining that the more than two navigation signals were received at substantially the same angle of arrival, determine that the more than two navigation signals are spoofed;
compare the angles of arrival for the navigation signals to at least one expected angle of arrival, wherein the at least one expected angle of arrival is at least one of: (i) above a horizon or (ii) based on the information about the expected or actual positions of the plurality of satellites stored in the at least one memory;
determine whether at least one of the navigation signals was received at an angle of arrival different from the at least one expected angle of arrival; and
in response to determining that the at least one navigation signal was received at an angle of arrival different from the at least one expected angle of arrival, determine that the at least one navigation signal is spoofed; and

wherein, to suppress any of the navigation signals determined to be spoofed, the at least one processor is configured to control the plurality of amplitude and phase adjusters to weight the plurality of navigation signals from different channel receivers.