inertial guidance (or navigation)
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio.
a self-contained, automatic guidance system composed of gyroscopes, accelerometers, and computers and used to control rockets, airplanes, submarines, etc.: it continuously measures acceleration, calculates the present speed and position, and compares this to an assigned course
Used by arrangement with John Wiley & Sons, Inc.