Inertial navigation consists of at least a computer and a platform (or module) containing accelerometers, gyroscopes or other motion sensors. At the beginning, the outside world (operators and GPS receivers, etc.) provides the initial position and speed to the inertial navigation system. After that, the inertial navigation system continuously updates the current position and speed by integrating and calculating the information from the motion sensor. The advantage of inertial navigation is that after the initial conditions are given, the current position, direction and speed can be determined without external reference.

By detecting the acceleration and angular velocity of the system, inertial navigation can detect position changes (such as east or west movement), velocity changes (speed magnitude or direction) and attitude changes (rotation around various axes). Its need for no external reference makes it naturally immune to outside interference or deception.