System and method for navigation and targeting in GPS-challenged environments using factor graph optimization

An aircraft configured for entering and exiting at least one GPS-challenged airspace, comprising:

• at least one sensor configured to sense one or more observable signals corresponding to at least one target, the one or more observable signals are associated with targeting information including at least one of:
• GPS-challenged targeting information associated with at least one GPS-challenged sensing while the aircraft is navigating at least one trajectory through a GPS-challenged airspace;
• or
• subsequent targeting information associated with at least one sensing subsequent to the aircraft exiting the GPS-challenged airspace, each subsequent targeting information associated with an absolute position of the aircraft;
• at least one inertial reference system (IRS) configured to determine one or more state vectors of the aircraft associated with each sensing, the at least one state vector including at least one of:
• a GPS-challenged state vector associated with sensing while the aircraft is navigating the at least one trajectory through the GPS-challenged airspace;
• or
• a subsequent state vector associated with sensing subsequent to the aircraft exiting the GPS-challenged airspace, each subsequent state vector associated with an absolute position of the aircraft;
• at least one absolute positioning system configured to determine the at least one absolute position of the aircraft based on one or more received positioning signals;
• and
• wherein the aircraft further comprises a navigation and targeting system comprising:
• at least one processor in communication with the absolute positioning system and with the IRS;
• a memory in communication with the at least one processor, the memory configured for storage of:
• the targeting information and the one or more state vectors associated with each sensing;
• and
• instructions executable by the at least one processor;
• the instructions configured for causing the at least one processor to determine, subsequent to the aircraft exiting the GPS-challenged airspace and via factor graph optimization of the targeting information and the one or more state vectors based on the plurality of subsequent absolute positions, at least one targeting solution corresponding to a location of the at least one target.