42 results about "Pitch angle" patented technology

The invention relates to the technical field of attitude estimation, in particular to an attitude estimation method in a magnetic interference environment, which comprises the following steps of: obtaining a conversion relation between an Euler angle and a quaternion; calculating the quaternion at the next sampling moment; respectively solving a first state transition matrix, a first process noise matrix and a first prior covariance according to the first state equation; respectively solving a second state transition matrix, a second process noise matrix and a second prior covariance according to a second state equation; elements in the nb-series rotation matrix are used as observed quantities of state variables in the parameter-series rotation matrix, a corresponding Kalman gain is calculated, and a Jacobian matrix is designed by using the observed quantities; calculating an observation noise covariance matrix by using the Jacobian matrix; updating the Kalman gain by using the observation noise covariance matrix; and updating the state equation and the posterior covariance by using the updated Kalman gain and the observed quantity. The method solves the problem of how to prevent the calculation of the roll angle and the pitch angle from being influenced by magnetic interference when the magnetic interference exists.

The invention discloses a robust adaptive fusion filtering astronomical attitude determination method and system, and belongs to the technical field of radio navigation. The method comprises the following steps: constructing an integrated navigation model of a starlight and inertial integrated navigation system based on Lie group description; obtaining an observation residual error and an observation residual error covariance of a corresponding mode; robust and adaptive mode parallel sub-filtering is carried out, and posterior states and covariances in the two modes are updated; updating the mode probability; and fusing the updated posterior state with the covariance to obtain fusion output of parallel sub-filtering, taking the fusion output of the parallel sub-filtering as final estimation of the starlight and inertial integrated navigation system based on Lie group description, and outputting an astronomical attitude determination result containing an azimuth angle, a pitch angle and a roll angle. The high-precision astronomical attitude determination method has strong adaptability, strong robustness and accuracy when coping with complex noise and measuring outliers, and can realize high-precision astronomical attitude determination of starlight and inertial integrated navigation in a complex dynamic environment.

The invention discloses an equipment attitude automatic correction method and device and an optical terminal intensity instrument, the equipment attitude automatic correction method is applied to a preset monitoring terminal comprising a triaxial MEMS accelerometer and a magnetometer, and the method comprises the following steps: collecting acceleration and magnetometer data; calculating acceleration stable three-axis offset; calculating roll and pitch angles and determining a horizontal plane; positioning magnetic north and calculating a magnetic north azimuth angle; calculating a magnetic declination angle and a yaw angle by combining longitude and latitude; generating a rotation matrix and converting a coordinate system; judging angle change and updating the matrix; and completing calibration and attitude stabilization. According to the technical scheme provided by the invention, the monitoring terminal equipment can be ensured to automatically and accurately adjust and stably maintain the attitude after being installed, so that the effective operation of the earthquake monitoring and early warning system is ensured, and the earthquake disaster prevention and flooding earthquake (vibration) monitoring performance is improved.

The embodiment of the invention provides an aviation gravity and magnetic vector dynamic measurement method based on multi-source data synchronous fusion, and relates to the technical field of data acquisition, after sensor array data on a driving flight platform is acquired, a specific force measurement value, a carrier pitch angle, a carrier roll angle and a carrier motion parameter are calculated and output; calculating three output gravity disturbance components by adopting carrier motion parameters and specific force measurement values; fusing total field data of the optical pumping magnetometer to carry out magnetic vector calculation on three-component data of the fluxgate and outputting geomagnetic total elements; and taking a carrier pitch angle, a carrier roll angle, a carrier position, a carrier speed and a carrier course angle as carrier pose data, combining the geomagnetic total elements and the carrier pose data, and outputting a dynamic measurement result of the gravity-magnetic vector field. The problems that in the prior art, gravity measurement and magnetic measurement are separated, equipment redundancy is low in efficiency, collection time is asynchronous, and data precision is reduced are solved. The effect of high-precision, high-dynamic and high-efficiency synchronous acquisition of the gravity and magnetic vector data under the single platform is achieved.

The invention relates to a high and low orbit satellite tracking method based on geomagnetic correction. The method comprises the following steps: constructing a geomagnetic model, calculating an azimuth angle and carrying out magnetic field interference analysis; carrying out factory calibration by utilizing a three-dimensional geometric calibration mode, including horizontal correction and vertical correction; the current azimuth angle and pitch angle are continuously corrected based on the carrier coordinate system by using the signal intensity, and the deviation is obtained so as to continuously approach the real angle; utilizing the known coordinates of the three-dimensional space to inversely calculate the current position; and the current data is corrected by using the big data, so that the current data meets the use requirements. The current attitude angle and the satellite signal receiver are used for tracking the target satellite, and then the known azimuth angle is used for correcting the geomagnetic data, so that the azimuth angle precision is improved, the cost of a phased-array antenna or a mechanical antenna is reduced, the tracking precision is improved, and the tracking speed is improved.

The application belongs to the technical field of magnetic variable measurement, and solves the technical problem of poor magnetic field measurement precision caused by single attitude adjustment of the existing Hall measurement system. The vacuum Hall measurement system for the in-vacuum undulator comprises a vacuum chamber, a Hall probe and a motion execution mechanism. The motion execution mechanism comprises a guide rail and a pose adjustment mechanism. The Hall probe is movable along the extension direction of the guide rail. The pose adjustment mechanism drives the Hall probe to move three-dimensionally to measure the magnetic field distribution through the guide rail. The pose adjustment mechanism comprises a Z-direction swing platform to adjust the pitch angle of the guide rail, a Y-direction swing platform to adjust the roll angle of the guide rail, a Y-direction moving platform, an X-direction moving platform and a Z-direction moving platform. The application can adjust the attitude in two directions and the position in three directions in space, reduce the parasitic displacement, make the Hall probe move three-dimensionally in the undulator and improve the magnetic field measurement precision.

The application discloses a kind of space target abnormal change discrimination methods based on imaging auxiliary data, first acquire the azimuth and pitch angle of space target turntable theory and measured data, using improved amplitude limiting filtering algorithm to eliminate outliers;Filter estimation is carried out to the data after eliminating outliers, to obtain estimated real data to correct measured data;The actual similarity between the estimated real data and the theoretical data is calculated, and the similarity function is fitted;For continuous new time, the absolute value of the difference between the actual similarity and the estimated similarity obtained by the similarity function is taken as the similarity difference value.The application does not need astronomical positioning, can detect target orbit abnormal change while imaging target characteristics, improve the timeliness of research and judgment and the safety of space target on-orbit operation, effectively reduce the risk of space target collision, fill the blank of detecting target orbit abnormal change by using on-orbit satellite small aperture telescope.

This invention discloses a method for measuring the magnetic field pitch angle using rotating Doppler microwave reflection. A Doppler backscattering meter (DBS) simultaneously transmits X-mode and O-mode polarized microwave signals to the plasma and receives the scattered signals returning along the transmitted optical path. A beam splitter divides the received scattered signals into two paths: one path enters the original DBS, and the other enters a rotatable antenna to adjust the vibration direction of the received electric field component. Based on the steady-state discharge conditions of EAST, a high-speed rotating platform rotates the rotatable antenna 360° during the stable discharge period, completing the scanning of the vibration directions of the electric and magnetic field components of the scattered signal, thus obtaining the magnetic field pitch angle at the detection frequency cutoff layer. This method is low-cost, causes almost no interference to the plasma, and allows for real-time, interference-free measurement of the magnetic field pitch angle at a localized location within the core of a magnetic confinement fusion device.

The application discloses a method for measuring a pitch angle of a magnetic field in a core of a magnetic confinement fusion device, which comprises the following steps: simultaneously emitting microwave signals of X-mode and O-mode polarization to plasma by a Doppler backscattering diagnostic system (DBS), and receiving scattered signals returned along a transmission light path; dividing the received scattered signals into two paths by a beam splitter, one of which enters the original DBS, and the other of which enters a rotatable antenna for selecting a vibration direction of an electric field component; adjusting an included angle between the vibration direction of the electric field component of the rotatable antenna and the vibration direction of the electric field component of the DBS transmission antenna according to the vibration direction of the electric field component of the DBS transmission antenna, obtaining the vibration direction of the electric field component of the backscattering signal through the ratio of the signal intensity received by the two antennas, and further obtaining the pitch angle of the magnetic field. The above method has the advantages of low cost, almost no interference to plasma, high time resolution, and can be used for real-time measurement of the pitch angle of the magnetic field in the core of the magnetic confinement fusion device without interference.

The present invention discloses a method for estimating the pitch angle of an aerial target using a spaceborne radar based on satellite posture. The method comprises: selecting the position of the spaceborne radar, the position of the aerial target, the projection point of the aerial target on the ground, and the position of the center of the earth as reference points, and constructing a geometric relationship model between the spaceborne radar and the aerial target; obtaining a first parameter set and a second parameter set based on the geometric relationship model; constructing a first expression for a lower viewing angle according to the first parameter set, and constructing a second expression for a lower viewing angle according to the second parameter set; and jointly solving the pitch angle by using the first expression for the lower viewing angle and the second expression for the lower viewing angle. The present invention solves the problem of large errors in the pitch angle estimation value of the aerial target when the spaceborne radar undergoes posture transformation.

The embodiment of the application provides a dynamic measurement method for aviation gravity and magnetic vector based on multi-source data synchronous fusion, relates to the technical field of data acquisition, and outputs the specific force measurement value, the carrier pitch angle, the carrier roll angle and the carrier motion parameter after driving the flight platform to collect the sensing array data; adopts the carrier motion parameter and the specific force measurement value to output the gravity disturbance three components; fuses the total field data of the optical pumping magnetometer to perform the magnetic vector calculation and output of the geomagnetic full element of the flux gate three component data; takes the carrier pitch angle, the carrier roll angle, the carrier position, the carrier speed and the carrier heading angle as the carrier pose data, combines the geomagnetic full element and the carrier pose data, and outputs the dynamic measurement result of the gravity and magnetic vector field. The problems that the gravity and magnetic force measurement are separated in the prior art, the equipment is redundant and inefficient, the acquisition time is asynchronous, and the data precision is reduced are solved. The effect of high-precision, high-dynamic and high-efficiency synchronous acquisition of the gravity and magnetic vector data under a single platform is achieved.

The invention discloses a method for measuring the spiral angle of a core magnetic field of a magnetic confinement fusion device, and the method comprises the steps: transmitting X-mode and O-mode polarized microwave signals to plasma at the same time through a Doppler backscatterometer diagnostic system (DBS), and receiving a scattered signal returned along a transmitting light path; a received scattering signal is divided into two paths through a beam splitting sheet, one path enters an original DBS, and the other path enters a rotatable antenna and is used for selecting the vibration direction of a receiving electric field component; according to the vibration direction of the electric field component of the DBS transmitting antenna, the included angle between the vibration direction of the electric field component of the rotatable antenna and the vibration direction of the electric field component of the DBS transmitting antenna is adjusted, the vibration direction of the electric field component of a backscattering signal is obtained through the ratio of the received signal intensities of the two antennas, and then the magnetic field pitch angle is obtained. The method is low in cost, almost has no interference to plasma, has high time resolution, and can measure the magnetic field pitch angle at the local position of the core of the magnetic confinement fusion device in real time without interference.

This application describes creating, modifying, and bending electromagnetic solitons at large scales for the various applications. An electromagnetic soliton generator system controls the magnetic soliton such that the orientation, rotation rate, pitch angle, and magnetic field strength of the solitons are modified to provide the described standing waves and generate a magnetic flux differential.

The invention belongs to the technical field of magnetic variable measurement, and provides an in-vacuum Hall measurement system for an in-vacuum undulator, which solves the technical problem of poor magnetic field measurement precision caused by single attitude adjustment of an existing Hall measurement system. The in-vacuum Hall measurement system for the in-vacuum undulator comprises a vacuum chamber, a Hall probe and a motion executing mechanism, the motion executing mechanism comprises a guide rail and a pose adjusting mechanism, the Hall probe can move in the extending direction of the guide rail, and the pose adjusting mechanism drives the Hall probe to move in a three-dimensional mode through the guide rail to measure magnetic field distribution. The pose adjusting mechanism comprises a platform swinging around the Z direction so as to adjust the pitch angle of the guide rail; swinging the platform around the Y direction to adjust the overturning angle of the guide rail; a Y-direction moving platform, an X-direction moving platform and a Z-direction moving platform. According to the invention, the attitude in two directions and the position in three directions in the space can be adjusted, the parasitic displacement is reduced, the Hall probe is enabled to perform three-dimensional motion in the undulator, and the magnetic field measurement precision is improved.

This application discloses a geomagnetic sensor calibration method, apparatus, and electronic device, belonging to the field of electronic device technology. The method includes: when the geomagnetic sensor of the electronic device is detected to be subjected to magnetic interference, acquiring the current yaw angle, pitch angle, rotation angle, magnetic tilt angle, and Earth's magnetic field strength of the electronic device; determining the current standard triaxial magnetic field data of the electronic device based on the yaw angle, pitch angle, rotation angle, magnetic tilt angle, and Earth's magnetic field strength; determining the triaxial magnetic field deviation value of the geomagnetic sensor based on the measurement data of the geomagnetic sensor and the standard triaxial magnetic field data; and calibrating the geomagnetic sensor based on the triaxial magnetic field deviation value.

The invention discloses an attitude angle stabilizing method and device of an inertial measurement unit, equipment and a storage medium. The attitude angles comprise a pitch angle, a roll angle and a course angle, and the method comprises the following steps: acquiring a current attitude angle of the inertial measurement unit; determining whether filtering stabilization needs to be carried out on the current attitude angle according to the angle fluctuation condition at the current moment; if the current attitude angle needs to be subjected to filtering stabilization, obtaining a stability coefficient, performing filtering stabilization on the current attitude angle according to the stability coefficient to generate a current stable angle, and outputting the current stable angle; and if the current attitude angle does not need to be subjected to filtering stabilization, outputting the current attitude angle. According to the attitude angle stabilizing method of the inertial measurement unit, small-amplitude fluctuation of the attitude angle can be filtered out, and stable attitude angle data can be output.

The application discloses a method for calculating an interplanetary cross scaling coefficient according to particle phase space density correlation characteristics, comprising the following steps: obtaining particle flux sequences of a standard A star and a to-be-scaled B star; under a T89c external magnetic field model, respectively calculating a modified third adiabatic invariant and a second adiabatic invariant of the A star and the B star, and calculating a local magnetic field intensity; performing uniform grid division on time and the third adiabatic invariant, and performing logarithmic uniform grid division on the first adiabatic invariant and the second adiabatic invariant; obtaining a local pitch angle and energy in the grid; screening out points with data in the same grid to obtain particle phase space densities of the A star and the B star respectively; calculating a particle phase space density average in the grid; respectively establishing particle phase space density matrices of the A star and the B star; screening out points with data in the same grid of the particle phase space density matrices of the two stars to obtain a cross scaling coefficient of the B star.

The invention discloses a method for measuring a pitch angle of a magnetic field by rotating Doppler microwave reflection, which comprises the following steps of: simultaneously transmitting X-mode and O-mode polarized microwave signals to plasma through a Doppler backscatterometer diagnostic system (DBS), and receiving a scattered signal returned along a transmitting light path; a received scattering signal is divided into two paths through a beam splitting sheet, one path enters an original DBS, and the other path enters a rotatable antenna to be used for adjusting the vibration direction of a received electric field component; based on the EAST steady-state discharge condition, the rotatable antenna is rotated by 360 degrees through a high-speed rotating platform in the discharge stationary period, scanning of the vibration direction of the scattering signal electric field component and the vibration direction of the magnetic field component is completed, and the magnetic field pitch angle at the detection frequency cut-off layer is obtained. The method is low in cost, almost has no interference to plasma, and can measure the magnetic field pitch angle at the local position of the core of the magnetic confinement fusion device in real time without interference.

The invention relates to a deep sea magnetometer in-situ correction control method, and relates to the technical field of magnetometers, and the method comprises the following steps: S01, obtaining an original magnetic field measurement value, a carrier attitude angle, an angular velocity and a depth in real time through a magnetometer, an inertial navigation unit and a depth sensor carried by a carrier; calculating a geomagnetic reference field and a change rate thereof based on the carrier position and a global geomagnetic model; and S02, constructing a reinforcement learning agent taking the interference model parameter covariance matrix as input, and dynamically generating a maneuvering instruction sequence of yaw angle increment, pitch angle increment, depth increment and stabilization time under the condition that maneuvering constraint conditions of the deep sea operation platform are met. The novel method for in-situ detection and compensation control of the magnetic deviation of the magnetometer carrier can be realized without depending on water surface type maneuvering navigation, so that the accuracy and the reliability of deep sea magnetic measurement data are guaranteed.

The invention discloses a mobile equipment attitude estimation method and device based on IMU nine-axis data, and the method comprises the steps: firstly initializing a quaternion describing the attitude of mobile equipment by taking an east-north-sky coordinate system as a world coordinate system according to the data of an acceleration sensor and a magnetic field sensor in an initial window; the environment magnetic field distribution in a complex environment is approximated to a multi-magnetic dipole magnetic field distribution model, and a weight attenuation geomagnetic field estimation method is designed according to the attenuation characteristics of the magnetic dipole model; then, a multi-layer sliding window method is used, and a gyroscope, an acceleration sensor and a magnetic field sensor are respectively used for estimating quaternion, a roll angle, a pitch angle and a yaw angle of the mobile equipment; finally, the fusion effect of nine-axis sensor data estimation equipment attitude is optimized by using a self-adaptive complementary filter. The precision and the stability of attitude estimation of the mobile equipment can be remarkably improved.

The invention provides an oscillation detection method and an oscillation detection device. The oscillation detection method comprises the following steps: generating an oscillation magnetic field through an oscillation generation device; the oscillation generating device is arranged on an object to be detected; continuously collecting real-time speed information of the to-be-detected object in the oscillation process; performing data processing on the real-time speed information to obtain a pose state oscillogram of the to-be-detected object in the oscillation process; the pose state oscillogram comprises the oscillogram of pitch angle information and roller angle information of the to-be-detected object in the oscillation process. In the embodiment of the invention, the real-time speed information of the to-be-detected object can be continuously detected through the measuring unit to obtain the pose state oscillogram of the to-be-detected object in the oscillation process, so that people can read whether the rotation center and the mass center of the permanent magnet deviate and cause vibration or not through the pose state oscillogram; and whether resonance exists between the oscillator and the helmet or not is judged, so that the vibration phenomenon and the resonance phenomenon can be eliminated.

The invention provides a seaplane take-off and landing process dynamics calculation method and system suitable for high sea conditions, and the method comprises the steps: obtaining the hydrodynamic test data of a ship-shaped fuselage at the bottom of a seaplane in real time, and building a body coordinate system and a ground coordinate system; then establishing a height compensation model and an attitude compensation model based on the wave height to obtain a vertical distance and a pitch angle after wave influence correction, and calculating the infiltration area after wave influence at the current moment by adopting a specific calculation method; and finally, introducing the infiltration area influenced by waves on the basis of a total motion equation consisting of a centroid kinetic equation, a centroid kinematical equation, a rotation kinetic equation and a rotation kinematical equation, so as to establish an improved centroid kinetic equation, an improved centroid kinematical equation, an improved rotation kinetic equation and an improved rotation kinematical equation. Therefore, the real-time dynamic analysis of the take-off and landing process of the seaplane under the high sea condition is realized, and the method has remarkable rapidity, real-time performance and accuracy.

The invention discloses a method and a system for detecting an attitude angle of a telescope and related equipment. The method comprises the following steps: acquiring target acceleration data acquired by an acceleration sensor at a target time point; obtaining target geomagnetic intensity data collected by the magnetometer sensor at a target time point; determining a target roll angle of the telescope at the target time point and a target pitch angle of the telescope at the target time point according to the target acceleration data; determining an estimated yaw angle of the telescope at the target time point according to the target geomagnetic intensity data, a target roll angle of the telescope at the target time point and a target pitch angle of the telescope at the target time point; and correcting the estimated yaw angle according to the magnetic declination corresponding to the geographic position of the telescope at the target time point to obtain an actual yaw angle of the telescope at the target time point. The cost of detecting the attitude angle of the telescope can be reduced.

The application discloses a target track simulation method of an infrared search and tracking device. Firstly, velocity components in X and Y directions are calculated according to the movement speed and the heading angle of a target; then, the time when the target is detected by the device in a current frame is calculated more accurately according to the velocity of the target in the X direction and the rotating speed of the device, and the specific method is as follows: the 360-degree azimuth of the device is discretized at equal time intervals to coarsely predict the time when the target is detected by the device, and linear interpolation is performed on the coarsely predicted time to realize more accurate time prediction; finally, the azimuth and the pitch angle of the target in the current frame are calculated in combination with the movement speed of the target in the X and Y directions and the distance between the target and the device. The method realizes accurate time simulation of the target in each frame through the method of azimuth equal-time discretization and linear interpolation, finally realizes accurate simulation of the azimuth and the pitch angle, and effectively improves the accuracy of target track simulation.

The invention belongs to the technical field of astronomical telescopes, and particularly relates to a quick calibration method and system for a double-horizontal telescope rack. The method comprises the following steps: S1, establishing a coordinate model, and determining observation coordinates and a mark star position; s2, performing azimuth angle deviation calibration according to the observation coordinates obtained in the S1 and the position of the mark star to obtain a calibration state in which the azimuth angle deviation is eliminated; s3, performing pitch angle deviation calibration and corresponding offset calculation according to the calibration state in which the azimuth angle deviation obtained in the step S2 is eliminated; s4, establishing a deviation correction curve through simulation according to the pitch angle deviation data obtained in the S3, and optimizing the pitch angle deviation by using a K value adjustment method to obtain an optimized pitch angle deviation calibration result; and S5, according to a pitch angle deviation optimization result completed in the step S4, performing experimental verification and obtaining a conclusion. The method has the advantages that efficient calibration of the azimuth angle and pitch angle deviation of the rack can be guaranteed, and therefore the pointing precision of the telescope is remarkably improved.

The embodiment of the invention provides a method for determining the occupancy condition of a position and related equipment, and the method comprises the steps: obtaining measurement data, the measurement data comprises a first distance and an angle, and the angle comprises a first azimuth angle and / or a first pitch angle; according to the first distance, a first parameter value used for indicating the object occupation condition of the first position is determined; determining an angle adjustment factor corresponding to the first position according to the angle; according to the first parameter value and the angle adjustment factor, a second parameter value corresponding to the first position is determined, and the second parameter value indicates the object occupation condition of the first position. The object occupancy condition of the first position is determined by means of more information, the influence of the distance and the angle on the object occupancy condition of the first position is independently determined, and the accuracy of the finally obtained position occupancy condition is improved.

The invention discloses a tracking maintaining method of a moving platform warning radar under a large pitch dimension error. The tracking maintaining method comprises the following steps: carrying out attenuation compression on a pitch angle to obtain a compressed pitch angle; converting the compressed pitch angle and other measurement information to an earth-centered earth-fixed coordinate system to obtain a first offset, and obtaining a measured earth-centered earth-fixed value according to the first offset; obtaining a filtering result at the t-th moment according to the measured earth-centered earth-consolidation value at the t-th moment and the predicted position at the t-th moment; based on an inversion mode, a pitch angle of compression filtering is obtained according to a filtering result; sequentially carrying out amplification reduction and threshold judgment on the compressed and filtered pitch angle to obtain a pitch angle to be output; and obtaining a final earth-centered earth-fixed output value according to the pitch angle to be output and other filtering information. The tracking maintaining method is a compression processing method based on the pitching dimension, can keep continuous tracking of the target in the direction, and has certain pitching dimension tracking precision.

The application provides a two-dimensional rotary table capable of realizing adaptive high-precision tracking and a control method thereof, relates to a photoelectric tracking two-dimensional rotary table and a control method, and aims to solve the technical problem of poor environmental adaptability of a high-precision tracking system of an existing two-dimensional rotary table and the requirement of meeting high-precision tracking in a large speed span range. According to the application, a parameter identification model is established, the changes of the wire-wound moment, the friction moment and the rotational inertia are identified when the two-dimensional rotary table is influenced by factors such as temperature, azimuth angle and pitch angle, the control parameters are automatically changed through parameter identification, and it is verified through ground test that the method can realize high-precision tracking in a large speed span range.

The application discloses a kind of X-Y formula radio telescope pointing calibration method, its steps include: 1) the pointing calibration model Δy of X-Y formula telescope is constructed=C2+C3sinx-C4cosx+C7cosysinx+C8coty;Wherein, C1=α, C2=β, C5=-δ, C6=-γ, C7=χGl, α,β respectively is the corresponding code disc reading when x=0, y=0, γ is the positive direction of pointing axis Y axis deviation angle, δ is the positive direction of Y axis positive direction X axis deviation angle, ε is the deviation angle of X axis negative direction and geographic north pole, it is the angle between X axis negative direction in east-zodiacal plane and geographic east, χ is the deviation coefficient of pointing in pitch caused by gravity moment, it is the pitch angle deviation coefficient caused by atmospheric refraction;2) the numerical value of C1~C8 is obtained by using pointing error measurement data fitting calculation;3) using pointing calibration model calibrates X-Y formula telescope.

The present invention discloses a MEMS IMU initial alignment method based on nonlinear optimized magnetic heading, comprising the following steps: S1, determining the true magnetic vector and magnetic declination of the current position through a world geomagnetic model; S2, calculating the initial magnetic heading, pitch angle, and roll angle through the MEMS IMU; S3, constructing a nonlinear optimized magnetic heading model; S4, solving the nonlinear optimized magnetic heading model to obtain an optimal rotation matrix calculated based on an optimal rotation matrix increment, thereby converting the optimal initial alignment heading angle ψ b es t; This initial alignment method solves the problem of insufficient alignment accuracy of the existing MEMS IMU initial alignment method based on magnetometer. It has high reliability, strong versatility, high algorithm operation efficiency, simple operation, high accuracy and good practicality.