Global Positioning Systems and Inertial Measuring Unit Ultratight

An ultratight coupling method generates navigation error state information from an integration Kalman filter for updating the navigation solution based upon inertial measurement data and computes pseudorange and pseudorange rate data from the navigation solution and from ephemeris data, to generate the prompt, early and late replica signals that drive the signal correlators having quadrature outputs samples by a federation of Kalman prefilters providing errors residuals to the integration Kalman filter in a closed coupled tracking loop. The coupled tracking loops offer improved tracking of the received signal based upon updated navigation solution.