Dead reckoning based on heading and time alone, but if you have a good INS it's not affected by wind only by accuracy of the gyroscopes/sensors. Current system

Dead reckoning based on heading and time alone, but if you have a good INS it's not affected by wind only by accuracy of the gyroscopes/sensors. Current systems drift by about 0.5 miles per hour. And that's normal commercial grade systems, I'm sure the military has an option for better systems if they need them.