Another requirement for compass accuracy is that if the current carrier's pointing is north, then the compass's output should be 0 degrees. If the carrier's pointing is east, then the compass's output should be 90 degrees. The measured and true values should be within the error range. Accurate fit within.
Another principle of choosing a compass is whether the compass is resistant to harsh environments. Compass has a natural disadvantage, that is, the accuracy will be worse in an environment with magnetic interference. The compass uses the direction of the Earth's magnetic field to determine the azimuth. If the Earth's magnetic field is disturbed or distorted, the accuracy of the azimuth measurement will decrease. Ferric materials, batteries, motors, large currents, etc. can cause disturbances to the Earth's magnetic field. The closer these substances are to the compass, the more severe the interference. So if you want the compass to be accurate, you can only stay away from the interference source, but in many cases this is not feasible. So the only way to solve the problem is to do a magnetic calibration. During the magnetic calibration process, the compass rotates together with the measured object (ie, the interference source) in a certain way to learn the surrounding magnetic environment, thereby distinguishing which magnetic interference is, which is the geomagnetic field, and through this learning, the interference is eliminated, thereby Get high-precision azimuth output.