What is a Magnetometer?

Magnetometers (Magnetic, M-Sensor) are also called geomagnetism and magnetic sensors. They can be used to test the strength and direction of magnetic fields and the orientation of positioning equipment. The principle of the magnetometer is similar to that of the compass. Angle.

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Since the earth's gravity field is equivalent to known information, when the carrier is moving smoothly, it can completely rely on the measurement information collected from the meter to calculate the other two attitude information of the carrier in addition to the navigation. If the meter and other sensors are used, If the magnetometer is used in combination, the complete carrier attitude information can be measured in a variety of motion situations. ^[1]

Magnetometer is a kind of sensor that can measure the intensity of ambient magnetic field. In this paper, the required azimuth information of the carrier is obtained by using the magnetometer to measure the magnetic field intensity. As a practical device, the existence of errors is unavoidable. At present, the errors of magnetometers are generally divided into their own internal errors, application installation errors, and errors.

There are many physical principles that can measure magnetic fields. They are classified according to different principles. Common scalar magnetometer principles include proton precession magnetometers, Overhauser magnetometers, alkali metal light pump magnetometers, and common vector magnetometers. Fluxgate magnetometer, reluctance magnetometer, etc. This article mainly introduces the fluxgate magnetometer.

Fluxgate magnetometer is a kind of magnetometer that works based on the non-linear characteristics of soft magnetic material when its magnetization is saturated. It is used to accurately measure the stable or low-frequency alternating magnetic field with a size of one thousandth of T or less. Its application The scope covers many areas such as space exploration and geophysics. ^[2]

It is a device that measures the magnetic field by using the non-linearity in the saturation region when the ferromagnet is magnetized. When a ferromagnet made of soft magnetic material is magnetized, due to the non-linearity of the magnetization, the external field can be modulated, so that the sensor output is related to the external field. The magnitude of the external field can be obtained by modulating the even harmonic signal of the magnetic field frequency and detecting the magnitude of the even harmonic.