C. Electronic compass
The Electronic compass uses the geomagnetic field to point
to the North Pole. An electronic compass consists of both a
plane (horizontal) (two dimensional) and a three dimensional
electronic compass. Although the global positioning system has
a wide range of applications in navigation, positioning, velocity,
and orientation, its signal is often degraded due to terrain and
surface features of the block, therefore, it can lead to some
inaccuracy or even become unusable. In order to improve the
accuracy of GPS signals, users can use a combination of some
directional navigation methods. The electronic compass
designed to compensate for errors. It can be a signal
compensation of a global positioning system to ensure the
effectiveness of a navigation message. Most importantly, it can
also operate in case of the failure of the global positioning
system.