A system, comprising: a first platform comprising a first navigation unit, the first navigation unit comprising a first global position system sensor configured to provide first GPS position coordinates and a first inertial navigation system sensor configured to provide first INS position coordinates; a second platform comprising a second navigation unit, the second navigation unit comprising a second GPS sensor configured to provide second GPS position coordinates and a second INS sensor configured to provide second INS position coordinates; and a position system on the first platform and communicatively coupled to the first and second navigation units, configured to determine a first GPS position vector from first and second GPS position coordinates at a first time, a second GPS position vector from first and second GPS position coordinates at a second time, a first INS position vector from first and second INS position coordinates at a first time, and a second INS position vector from first and second INS position coordinates at a second time; said position system further configured to determine GPS-change vector from said first and second GPS position vectors, said GPS change vector denoting a relative change in position between the first platform and the second platform between the first and second times, and an INS-change vector from said first and second INS position vectors, said INS change vector denoting a relative change in position between the first platform and the second platform between the first and second times; wherein said position system is further configured to determine if the INS change vector is not substantially equal to the GPS change vector, and if not, the position system is configured to correct the second GPS position vector based on the INS change vector. a first platform comprising a first navigation unit, the first navigation unit comprising a first global position system sensor configured to provide first GPS position coordinates and a first inertial navigation system sensor configured to provide first INS position coordinates; a second platform comprising a second navigation unit, the second navigation unit comprising a second GPS sensor configured to provide second GPS position coordinates and a second INS sensor configured to provide second INS position coordinates; and a position system on the first platform and communicatively coupled to the first and second navigation units, configured to determine a first GPS position vector from first and second GPS position coordinates at a first time, a second GPS position vector from first and second GPS position coordinates at a second time, a first INS position vector from first and second INS position coordinates at a first time, and a second INS position vector from first and second INS position coordinates at a second time; said position system further configured to determine GPS-change vector from said first and second GPS position vectors, said GPS change vector denoting a relative change in position between the first platform and the second platform between the first and second times, and an INS-change vector from said first and second INS position vectors, said INS change vector denoting a relative change in position between the first platform and the second platform between the first and second times; wherein said position system is further configured to determine if the INS change vector is not substantially equal to the GPS change vector, and if not, the position system is configured to correct the second GPS position vector based on the INS change vector.