What is magnetometer?

A magnetometer is a device that measures magnetic fields or magnetic dipole moment. Different types of magnetometers are used to measure the direction, strength, or relative change of a magnetic field at a specific location. Magnetometers are widely used in surveying (e.g., detecting buried pipelines or shipwrecks), geophysics to measure magnetic anomalies of the Earth, archaeology to locate buried features, navigation (as a component of electronic compasses), and in the military to detect submarines and other magnetic targets. They are also used in spacecraft to orient the vehicle and stabilize its altitude.