Patent ID: 8515672

Claim:
A navigation system for performing a transfer alignment, the navigation system comprising: a set of local inertial sensors; a local strap-down navigation processor coupled to the set of local inertial sensors, the local strap-down navigation processor receiving inertial navigation data from the set of local inertial sensors and converting the inertial navigation data into a navigation solution; a local Kalman filter coupled to the local strap-down navigation processor, the local Kalman filter receiving the navigation solution produced by the local strap-down navigation processor, the local Kalman filter further coupled to a master Kalman filter; wherein the local Kalman filter receives a first message from the master Kalman filter comprising a Precision Transfer Alignment Message (PTAM) that includes at least one navigation aid measurement; wherein the local Kalman filter inputs the navigation aid measurement into a measurement formation algorithm and calculates a measurement residual based on the navigation aid measurement; wherein the local Kalman filter receives a second message from the master Kalman filter comprising a Reset Transfer Alignment Message (RTAM) that includes a bias correction applied by the master Kalman filter as a navigation reset; wherein the local Kalman filter inputs the bias correction into a state propagation algorithm where the bias correction provided by the bias correction is added to a navigation state of the local Kalman filter and propagated.