Patent ID: 7305303

Claim:
A navigation system comprising: a plurality of sensors, wherein each sensor outputs sensor information, wherein the sensor information comprises altitude information; an inertial navigation unit communicatively coupled to at least one of the plurality of sensors to generate a navigation solution based on at least a portion of the sensor information; a motion classifier communicatively coupled to at least one of the plurality of sensors, wherein the motion classifier generates position information based on at least a portion of the sensor information; a signal-of-opportunity interface to receive at least one signal of opportunity and to generate signal-of-opportunity information based on the signal of opportunity; a Kalman filter communicatively coupled to the inertial navigation unit, the motion classifier, and the signal-of-opportunity interface, wherein the Kalman filter generates corrective feedback as a function of the navigation solution and, when available, at least one of the following: at least a portion of the sensor information, the position information output, and the signal-of-opportunity information; wherein the corrective feedback is used by the inertial navigation unit to generate the navigation solution.