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How is a gyrocompass different from a magnetic compass?
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gyrocompass
The gyrocompass aboard the National Oceanic and Atmospheric Administration's (NOAA) ship Rainier. Gyrocompasses are navigational instruments that use a continuously driven gyroscope to accurately seek the direction of true (geographic) north.
A gyrocompass and a magnetic compass differ primarily in their operating principles and their susceptibility to external interference.
- Operating Principle: A magnetic compass relies on the Earth's magnetic field, aligning a magnetized needle with magnetic north. In contrast, a gyrocompass uses a continuously driven gyroscope that seeks true (geographic) north by utilizing the Earth's rotation and the force of gravity.1234
- Interference: Magnetic compasses are subject to variation (or declination) and deviation, which is the deflection caused by local magnetic influences like steel structures or ore deposits. Because it is nonmagnetic, a gyrocompass is immune to these magnetic interferences.312
- Application: While magnetic compasses are used across various vehicles, including aircraft, the gyrocompass is a primary navigational device for ships and submarines. Notably, a gyrocompass is generally unsuitable for aircraft because high speeds can disrupt its north-seeking properties.31