Patent ID: 7250903

Claim:
A global positioning system (GPS) spoofer and repeater mitigation system, comprising: a) a multi-element antenna array for receiving GPS L1/L2 RF signals; b) a plurality of RF downconverters for converting said L1/L2 RF signals to IF frequency analog signals suitable for analog-to-digital (A/D) conversion; c) a plurality of analog-to-digital (A/D) converters associated with said plurality of RF downconverters for converting said IF frequency analog signals to digital signals; d) a digital complex weighting system (DCWS) for multiplying each of said digital signals by a complex (gain/phase) weight and adding the weighted digital signals together to form a plurality of beams; e) a GPS receiver, comprising: i. a plurality of receiver correlators for receiving said plurality of beams and tracking them by correlating them with a local reference of a transmit code of the GPS, said correlating including use of a GPS correlation process to generate the information necessary to derive the electronic angle of arrival to desired or undesired signals; ii. a GPS processor for processing the output beams from said plurality of receiver correlators, said GPS processor including logic to detect a common electronic angle of arrival among multiple tracked satellites, in order to detect repeaters; and, iii. a local code generator for receiving a processed output from said GPS processor and providing a local code to said plurality of receiver correlators; and, f) a digital beamformer processor operatively connected to said DCWS and said GPS processor for providing complex weights to said DCWS for creating said plurality of beams, and for allowing the introduction of synthetic nulls in the direction of spoofer and repeater threats, wherein said DCWS, said GPS receiver and said digital beamformer processor cooperate to provide digital spatial nulling to mitigate GPS spoofer and repeater threats.