Inertial Navigation System

Developed in 1960s, the INS (Inertial Navigation Systems) was a collection of extremely precise accelerometers and gyroscopes, used to calculate and display an object’s position, speed and direction relative to a known starting point. eg. Once an aircraft's or submarine’s INS is calibrated to a known reference point, it can “dead reckon” the target accurately from that point forward. The earlier INS did not take into account the curvature of the Earth and pilots could still navigate using this basic navigation system.