Inventors:
Todd E. Humphreys - Austin TX, US
Brent M. Ledvina - San Francisco CA, US
William J. Bencze - Half Moon Bay CA, US
Bryan T. Galusha - San Francisco CA, US
Clark E. Cohen - Washington DC, US
Assignee:
COHERENT NAVIGATION, INC. - San Mateo CA
International Classification:
G01S 19/47, G01S 19/38, G01S 19/46
US Classification:
3423573, 34235721, 34235729
Abstract:
A method for upgrading GNSS equipment to improve position, velocity and time (PVT) accuracy, increase PVT robustness in weak-signal or jammed environments and protect against counterfeit GNSS signals (spoofing). A GNSS Assimilator couples to an RF input of existing GNSS equipment, e.g., a GPS receiver, and extracts navigation and timing information from available RF signals, including non-GNSS signals, or direct baseband aiding, e.g., from an inertial navigation system, frequency reference, or GNSS user. The Assimilator fuses the diverse navigation and timing information to embed a PVT solution in synthesized GNSS signals provided to a GNSS receiver RF input. The code and carrier phases of the synthesized GNSS signals are aligned with those of actual GNSS signals to appear the same at the target receiver input. The Assimilator protects against spoofing by continuously scanning incoming GNSS signals for signs of spoofing, and mitigating spoofing effects in the synthesized GNSS signals.