What is a north finding system
The north finding system is one of the important applications of inertial navigation technology. By configuring high-precision inertial sensors to form a precision inertial measurement system, it can accurately sense the relative position parameters of the carrier, calculate the coordinate position, orientation, attitude and other information resources of the carrier through the system software solution program, and can provide these information resources to other devices. The north finding system is widely used in both military and civilian fields.
What is a north finder
The North finder is an inertial measurement system that uses the gyroscopic principle to measure the earth’s rotational angular velocity and thus determine the true north position. Gyroscope is a kind of inertial measurement element with mechanical rotating parts, which has the advantages of shock resistance, high sensitivity, long life, low power consumption and reliable integration. It can be measured in the local horizontal projection direction (i.e. true north position), independent of weather, day and night time, geomagnetic field and site visibility conditions.
Working principle and application of north finder
Gyroscopic north finder is an instrument that uses the basic characteristics of gyroscopes and determines the meridian direction (true north direction) of the point where the carrier is located by measuring the earth’s rotation rate. When the axis of the gyroscope is parallel to the earth’s rotation axis, the gyroscope will be stable, but if the gyroscopic axis is slightly off, it will precession. In this way, gyroscopes can be used to determine the north with high precision. It has the characteristics of high orientation accuracy, short measurement time, free from climatic conditions and autonomous orientation at any time and place (except high latitudes).
As a kind of azimuth indicating instrument, gyro north finder is widely used not only in satellite, missile, high precision inertial navigation system initial alignment and other national defense high-tech fields. Moreover, it has been widely used in many fields such as geophysical exploration, coal mining, geodetic survey, mining, underground drilling engineering, tunnel digging, autonomous driving system of unmanned vehicles, and on-board positioning directional navigation system.
Classification of the north finder
Fiber optic north finder
At present, most of the commonly used north finder are designed based on fiber optic gyroscope, but the fiber optic gyroscope is large and bulky, and the battery life is short, which is not suitable for narrow areas. The Fiber-optic gyroscope (GYRO) north finding system can measure the north azimuth Angle, has the characteristics of long life and simple structure, and is widely used in the field special operations for target positioning and navigation. The ER-NFS-03 Low Cost 3 Axis FOG North Seeker uses a closed-loop fiber optic gyroscope as its core component, which is mainly composed of an inertial measurement unit (IMU), a digital signal processing unit and a mechanical part mechanism. It can provide true north azimuth for the carrier. It is widely used in coal mining, oil drilling, tunnel construction, geodetic survey, missile launch, static initial alignment of weapon aiming radar, antenna, vehicle direction control and other fields. Ideal for mining applications.
However, the measurement accuracy of fiber optic gyroscope is greatly affected by temperature, and in practical measurement, because the fiber optic gyroscope can not be placed completely horizontally, the measurement accuracy is further reduced, and the accuracy of the north finding result is greatly reduced.
MEMS north finder
Therefore, a small size mems gyroscope that avoids signal interference is needed to measure the earth rotation rate, and through the improvement of the north finder structure, the instrument can accurately determine the north.
ER-MNS-06 MEMS North Seeker is the world’s smallest Triaxial MEMS North Seeker, which is composed of a three-axis MEMS gyroscope and accelerometer. It has the characteristics of small size, light weight, low power consumption, and resistance to harsh mechanical environment, and is widely used in mining, tunnel construction and other fields.