A fibre optic gyrocompass is a
compass
A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with ...
and instrument of
navigation
Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another.Bowditch, 2003:799. The field of navigation includes four general categories: land navigation, ...
. It is sometimes part of a ship's set of compasses, which also include a conventional
gyrocompass
A gyrocompass is a type of non-magnetic compass which is based on a fast-spinning disc and the rotation of the Earth (or another planetary body if used elsewhere in the universe) to find geographical direction automatically. The use of a gyroc ...
and a
magnetic compass
A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It commonly consists of a magnetized needle or other element, such as a compass card or compass rose, which can pivot to align itself with ...
. The compass comprises a
fibre optic gyroscope
A fibre-optic gyroscope (FOG) senses changes in orientation using the Sagnac effect, thus performing the function of a mechanical gyroscope. However its principle of operation is instead based on the interference of light which has passed throug ...
sensor, which links to a computer and then locates north. This in turn links to a compass readout to provide a heading.
[Seamanship Techniques:Shipboard and Marine Operations, D. J. House, Butterworth-Heinemann, 2004, p. 341] It has very high reliability and requires little maintenance during its service life.
The entire system usually includes a sensor unit, a control and display unit, and an interface and power supply unit. It is often linked with the ship's other navigational devices including
GPS
The Global Positioning System (GPS), originally Navstar GPS, is a Radionavigation-satellite service, satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of t ...
.
History
The first generation of
gyrocompass
A gyrocompass is a type of non-magnetic compass which is based on a fast-spinning disc and the rotation of the Earth (or another planetary body if used elsewhere in the universe) to find geographical direction automatically. The use of a gyroc ...
was based on fast-spinning discs and was requiring complex mechanics such as
gimbals
A gimbal is a pivoted support that permits rotation of an object about an axis. A set of three gimbals, one mounted on the other with orthogonal pivot axes, may be used to allow an object mounted on the innermost gimbal to remain independent of ...
of fluid suspended platform. The first practical apparatus were installed onboard vessels at the beginning of the 20th century.
The fibre optic gyrocompass is the first strapdown gyrocompass. The sensors are simply strapped to the chassis of the gyrocompass, avoiding the need for complex mechanics. The first fibre optic gyrocompass appeared on the market at the end of the 20th century, but did not really supersede the original mechanical gyrocompass, which remained the dominant technology on the market. A second generation of strapdown gyrocompass, based on
HRG technology, is now also available on the market.
See also
*
Gyrocompass
A gyrocompass is a type of non-magnetic compass which is based on a fast-spinning disc and the rotation of the Earth (or another planetary body if used elsewhere in the universe) to find geographical direction automatically. The use of a gyroc ...
*
HRG gyrocompass A HRG gyrocompass is a compass and instrument of navigation. It is the latest generation of maintenance-free instruments.
It uses a hemispherical resonant gyroscope, accelerometers and computers to compute true north. The HRG gyrocompass is a comp ...
References
Navigational equipment
Electronic navigation
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