Patent ID: 7274504

Claim:
A system for combining GPS and inertial navigation system sensor measurements for navigation in the presence of interfering signals, comprising: a GPS antenna and radio frequency receiver configured to receive GPS L 1 and L 2 signals as GPS signals; a GPS signal tracker configured to phase de-rotate and correlate GPS one or more of said GPS signals into early, late, and on-time I and Q signals; an extractor configured to extract vehicle range and carrier phase residual errors in the presence of interference signals, the extractor comprising a discriminator configured to compute at least two nonlinear transformations to generate linear measurements of pseudorange and carrier phase errors; a strapdown inertial measurement unit (IMU); a navigation Kalman filter for processing vehicle range and carrier phase residual signals to generate vehicle position, velocity, attitude, and time estimates along with IMU error estimates; a strapdown navigation processor for integrating the IMU measurements between the navigation Kalman filter processing intervals wherein the strapdown navigation processor is configured to receive navigation state error estimates from the navigation Kalman filter, and wherein the strapdown navigation processor is configured to receive navigation data from the IMU; a satellite navigation message decoder configured to provide satellite position, velocity, and acceleration (PVA) data to a processor-implemented satellite line of sight projection algorithm and to the navigation Kalman filter; and the processor implemented satellite line of sight projection algorithm configured to project navigation data onto the satellite line of sight, generate range and range rate measurements, and provide these measurements to one or more Numerically Controlled Oscillators configured to provide code and carrier signals for GPS signal phase de-rotation and correlation.