Inertial navigation is a method used to determine the position and velocity of an object without relying on external references. It utilizes sensors, such as accelerometers and gyroscopes, to measure changes in motion and orientation. By integrating these measurements over time, the system can calculate the object's current location. This technology is commonly found in various applications, including aircraft, submarines, and spacecraft. Inertial navigation systems are particularly useful in environments where GPS signals are weak or unavailable, allowing for accurate navigation in challenging conditions.