The purpose of compass

It is widely used in all directions, such as navigation, outdoor exploration, urban roads, map reading and other fields.

Compasses can be divided into two categories: relying on magnetic force and not relying on magnetic force. Compasses that rely on magnetic force can be subdivided into two categories:

1, a geomagnetic compass made according to the polarity of the earth's magnetic field, but the north-south direction indicated by this compass is different from the real north-south direction, and there is a magnetic declination;

2. Electronic compass adopts magnetic field sensor of magnetoresistive (MR) technology, which can correct the magnetic declination well and has been widely used in satellite positioning equipment. As for those who don't rely on magnetic force, they just rely on physical methods inside the equipment to indicate the direction, such as compass or inertial navigation system.

Extended data:

In the12nd century, China invented the basic form of modern compass-the dry compass. After being effectively improved by Arabs, it was introduced to Europe. However, the existing compass records in Europe predate Arabic, and the word al-konbas in Arabic seems to have originated from old Italian.

The dry compasses of later inland generations are mostly used for geomantic compasses and chronograph compasses, such as 174/l 189 Zeng Sanyi's Homophony Record and Ground Snail, or meridian needles, or sewing needles between meridian needles. It takes noon in the north and south of heaven and earth. ""snail "may be a compass to correct time, and its main purpose is to correct time.

The closer you get to the pole, the less useful the compass is. In the arctic, any direction on the surface can be regarded as the south; At the South Pole, any direction on the surface can be regarded as north.

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