Inertial navigation systems (INS) are technologies used to determine the position and movement of an object without relying on external references. They use sensors, such as accelerometers and gyroscopes, to measure changes in speed and direction. This information helps calculate the object's current location, making INS useful in various applications, including aircraft, submarines, and spacecraft. One of the key advantages of inertial navigation systems is their ability to operate in environments where GPS signals are weak or unavailable, such as underwater or in space. By continuously tracking motion, INS provides accurate navigation data, ensuring that vehicles like airplanes and missiles can reach their destinations safely.