The determination of
The system of navigation known as SINS (Ship's Inertial Navigation System), was developed after the Second World War (1939–45) for use in nuclear submarines which remain submerged for prolonged periods. The system must also be completely secure from outside detection. If a submarine's position is accurately plotted at the start of its voyage, and if all subsequent accelerations in their component directions can be measured, they can then be translated by calculation into speeds and distances which, when applied to the initial position, give the present position.
Inertial navigation is in fact an extremely sophisticated and precise method of dead reckoning, using accelerometers. The system can measure every acceleration due to speed and course changes, and can eliminate the effects of gravitational attraction, pitching and rolling, etc. The first major public demonstration of the system accuracy was in 1958 when the US nuclear submarines Nautilus and Skate navigated under the polar ice cap. Since then nuclear submarines have made submerged circumnavigations navigated by SINS. So accurate is the system that a margin of error of not more than 100–200 metres (330–650 ft) is expected after a circumnavigation.
Subjects: Maritime History.