Very classified so we only know bits and pieces. "Inertial navigation" is part of it - basically very precise dead reckoning. Using specialist equipment like laser ring gyros to get precise measurements.
Then also some other equipment like a magnetometer and magnetographic maps of the world to provide references to counteract the drift in any inertial navigation.
alt Hacker News
Very classified so we only know bits and pieces. "Inertial navigation" is part of it - basically very precise dead reckoning. Using specialist equipment like laser ring gyros to get precise measurements.
Then also some other equipment like a magnetometer and magnetographic maps of the world to provide references to counteract the drift in any inertial navigation.