Novatel Inc.

Walter D Petersen

Patrick C Fenton

John B Schleppe

A system detects, identifies, and optically tracks a jammer by calculating position and velocity information associated with the jammer based on jamming signals received at one or more antennas, and utilizing the position and velocity information to control one or more cameras. The cameras capture a series of images that include the calculated location, the expected movement of the jammer, or both. The system analyzes the images to extract motion information associated with one or more objects identified in the images. The system utilizes the calculated position and velocity information and the extracted motion information to determine which of the identified object in the images is the jammer. Further, the jammer motion information extracted from the images may be utilized to update the calculated position and velocity information associated with the jammer, to improve the overall accuracy of the tracking of the jammer.

GNSS jammer detection system with optical tracking and identification

A global position system receiver recovers the L1 and L2 carriers, the C/A-code measurements and the L1 and L2 P-code measurements by (a) producing an estimate of the L1 carrier phase angle and synchronizing a locally generated C/A-code with the L1 signal using an L1 delay lock loop and controlling, based on the locally generated C/A code, an L1 P-code generator that produces a synchronized version of the P-code; (b) initializing an L2 P-code generator based on the phase of the P-code generated by the L1 P-code generator; (c) determining, for the L2 signal, an estimate of signal power that is adjusted to compensate for noise; (d) determining an L2 carrier phase angle; (e) tracking the L2 P-code by adjusting an L2 P-code generator until the estimate of signal power is maximized. The GPS receiver also resolves a 1/2 cycle ambiguity in tracking the L2 P-code by comparing demodulated L1 P-code bits and L2 P-code bits. If the bits do not match in the majority of instances, the receiver determines that it is tracking the L2 P-code with 1/2 cycle error and adjusts its estimate of the P-code phase accordingly. The receiver may determine the reliability of the independently tracked L2 signal, by determining an associated carrier-to-noise ratio.

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Calgary, Canada

Walter D Petersen