阅读说明：本技术 一种光泵磁力仪探头转向误差磁干扰校准方法及系统 (Method and system for calibrating magnetic interference of probe steering error of optical pump magnetometer ) 是由 韩琦 李尤 葛林 王艺臻 李琼 王莘 于 2021-03-02 设计创作，主要内容包括：一种光泵磁力仪探头转向误差磁干扰校准方法及系统,属于航空磁补偿领域,目的是为了解决航磁探测期间飞机平台转弯时光泵磁力仪探头转向误差会引起磁干扰的问题。所述方法包括：在磁性清洁平台旋转中心安装光泵磁力仪、在旋转臂远端安装三分量磁力仪,在远离磁性清洁平台的场地内安装日变站探头；令磁性清洁平台旋转360°,在旋转过程中控制光泵磁力仪绕其自身的三轴转动,记录所述光泵磁力仪不同状态下光泵磁力仪和三分量磁力仪的输出；构造矩阵H-(HeadingError)和B；根据公式H-(headingerror)＝B～TA计算A。所述系统的光泵磁力仪安装在磁性清洁平台旋转中心,三分量磁力仪安装在磁性清洁平台旋转臂远端,日变站探头安装在远离磁性清洁平台的位置,数据收录设备采集各仪器的测量数据。(A method and a system for calibrating the magnetic interference of the probe steering error of an optical pump magnetometer belong to the field of aviation magnetic compensation and aim to solve the problem that the magnetic interference is caused by the probe steering error of the optical pump magnetometer when an aircraft platform turns during the aviation magnetic detection. The method comprises the following steps: an optical pump magnetometer is installed at the rotating center of the magnetic cleaning platform, a three-component magnetometer is installed at the far end of the rotating arm, and a probe of the solar substation is installed in a field far away from the magnetic cleaning platform; the magnetic cleaning platform is rotated by 360 degrees, the optical pumping magnetometer is controlled to rotate around the three axes of the optical pumping magnetometer in the rotating process, and the output of the optical pumping magnetometer and the output of the three-component magnetometer in different states of the optical pumping magnetometer are recorded; construction matrix H HeadingError And B; according to formula H headingerror ＝B T A is calculated. The system comprises an optical pump magnetometer arranged at the rotation center of a magnetic cleaning platform, a three-component magnetometer arranged at the far end of the rotating arm of the magnetic cleaning platform, a solar substation probe arranged at a position far away from the magnetic cleaning platform, and a data recording device for collecting the measurement of each instrumentAnd (4) data.)

1. A method for calibrating the magnetic interference of the steering error of an optical pump magnetometer probe is characterized by comprising the following steps:

the method comprises the following steps that an optical pump magnetometer is installed at the rotating center of a magnetic cleaning platform, a three-component magnetometer is installed at the far end of a rotating arm of the magnetic cleaning platform, and a solar substation probe is installed in a field far away from the magnetic cleaning platform;

enabling the magnetic cleaning platform to rotate 360 degrees, controlling the optical pump magnetometer to rotate around the three axes of the optical pump magnetometer in the rotating process, and recording the outputs of the optical pump magnetometer and the three-component magnetometer in different states of the optical pump magnetometer;

construction matrix H_HeadingErrorAnd matrix B:

wherein H_HeadingError＝H_test-H_reference，H_testIs the output of the optical pumping magnetometer, H_referenceIs the output of the diurnal variation probe;

B＝[cosx,cosy,cosz,cos²x,cos²y,cos²z,cosxcosy,cosxcosz,cosycosz]^Twherein, in the step (A),

v_x,v_y,v_zis the output of the three-component magnetometer on three spatial axes;

according to formula H_headingerror＝B^TAnd A, calculating a matrix A to finish the calibration of the magnetic interference of the steering error of the probe of the optical pump magnetometer.

2. The method of claim 1, further comprising:

and selecting a calibration field, wherein no external magnetic interference exists in a certain range near the calibration field, and the calibration field is used for arranging the magnetic cleaning platform and the daily variable station probe.

3. The method of claim 2, wherein the external magnetic interference comprises high voltage wires, power transformers, high power radio frequency radiation sources, and large ferromagnetic substances.

4. A method according to claim 2 or claim 3, wherein the in-site horizontal gradient is less than 1 nT/m.

5. The method of claim 2, wherein the range near the site is within 50m of the range near the site.

6. The method of claim 1, wherein the method is according to formula H_headingerror＝B^TThe specific method for calculating the matrix A comprises the following steps: according to formula H_headingerror＝B^TAnd A, estimating a matrix A by using a recursive least square method.

7. A magnetic interference calibration system for a steering error of an optical pump magnetometer probe is characterized by comprising a magnetic cleaning platform, an optical pump magnetometer, a three-component magnetometer, a solar substation probe and data recording equipment;

the optical pump magnetometer is installed at the rotation center of the magnetic cleaning platform, the three-component magnetometer is installed at the far end of the rotating arm of the magnetic cleaning platform, the solar substation probe is installed at a position far away from the magnetic cleaning platform, and the data recording equipment is used for collecting measurement data of the optical pump magnetometer, the three-component magnetometer and the solar substation probe.

8. The system of claim 7, further comprising a data processing apparatus coupled to the data capture device, the data processing apparatus having embedded therein:

a first calculation module configured to calculate according to formula H_HeadingError＝H_test-H_referenceCalculate H_HeadingErrorWherein H is_testIs the output of the optical pumping magnetometer, H_referenceIs the output of the diurnal variation probe;

a second calculation module configured to calculate the matrix B according to the following formula:

B＝[cosx,cosy,cosz,cos²x,cos²y,cos²z,cosxcosy,cosxcosz,cosycosz]^T

wherein v is_x,v_y,v_zIs the output of the three-component magnetometer on three spatial axes; and

a third calculation module configured to calculate according to formula H_headingerror＝B^TA computes a matrix A.

9. The system of claim 8, wherein the equation is according to formula H_headingerror＝B^TThe specific method for calculating the matrix A comprises the following steps: according to formula H_headingerror＝B^TAnd A, estimating a matrix A by using a recursive least square method.

Technical Field

The invention relates to a method for solving the problem that magnetic anomaly occurs in the flight process of a turning section caused by inherent turning errors of an optical pump probe in the aeromagnetic compensation process, which can be applied to the compensation of turning flight data in an aeromagnetic interference compensation system and belongs to the field of aeromagnetic compensation.

Background

The aeromagnetic compensation technology is a technology for compensating various external traceable magnetic interference types in the aeromagnetic detection process. The method comprises the steps of analyzing and modeling various interferences causing magnetic anomaly, then calculating the magnetic interference of the type in the aviation magnetic detection process by monitoring certain characteristics of a magnetic interference source, and then compensating the magnetic interference of the type by a data processing means to finally obtain a real magnetic field value measured by a probe. In the actual process of aeromagnetic detection, various types of magnetic interference exist, wherein the most significant of the measurable magnetic interference is the magnetic interference brought by the airplane platform, and the magnetic interference of the type can be subjected to coefficient calibration and compensation through a T-L model. However, when the aircraft platform turns, the magnetic interference caused by the steering error of the probe of the optical pump magnetometer in the magnetic interference occupies a certain proportion, so that the steering error of the probe of the optical pump magnetometer needs to be compensated at the turning position, so as to achieve a better compensation effect.

Disclosure of Invention

The invention aims to solve the problem that the steering error of an optical pump magnetometer probe causes magnetic interference when an airplane platform turns during aeromagnetic detection, and provides a method and a system for calibrating the steering error of the optical pump magnetometer probe by magnetic interference.

The invention relates to a method for calibrating the magnetic interference of the steering error of an optical pump magnetometer probe, which comprises the following steps:

the method comprises the following steps that an optical pump magnetometer is installed at the rotating center of a magnetic cleaning platform, a three-component magnetometer is installed at the far end of a rotating arm of the magnetic cleaning platform, and a solar substation probe is installed in a field far away from the magnetic cleaning platform;

enabling the magnetic cleaning platform to rotate 360 degrees, controlling the optical pump magnetometer to rotate around the three axes of the optical pump magnetometer in the rotating process, and recording the outputs of the optical pump magnetometer and the three-component magnetometer in different states of the optical pump magnetometer;

construction matrix H_HeadingErrorAnd matrix B:

wherein H_HeadingError＝H_test-H_reference，H_testIs the output of the optical pumping magnetometer, H_referenceIs the output of the diurnal variation probe;

B＝[cos x,cos y,cos z,cos² x,cos² y,cos² z,cos x cos y,cos x cos z,cos y cos z]^Twherein, in the step (A),

v_x,v_y,v_zis the output of the three-component magnetometer on three spatial axes;

according to formula H_{heading error}＝B^TAnd A, calculating a matrix A to finish the calibration of the magnetic interference of the steering error of the probe of the optical pump magnetometer.

Optionally, the method further comprises:

and selecting a calibration field, wherein no external magnetic interference exists in a certain range near the calibration field, and the calibration field is used for arranging the magnetic cleaning platform and the daily variable station probe.

Optionally, the external magnetic interference comprises high voltage wires, power converters, high power radio frequency radiation sources, and large ferromagnetic substances.

Optionally, the in-site horizontal gradient is less than 1 nT/m.

Optionally, the certain range near the site is within 50m of the site.

Optionally, said is according to formula H_{heading error}＝B^TThe specific method for calculating the matrix A comprises the following steps: according to formula H_{heading error}＝B^TAnd A, estimating a matrix A by using a recursive least square method.

The invention relates to a system for calibrating the magnetic interference of the steering error of an optical pump magnetometer probe, which comprises a magnetic cleaning platform, an optical pump magnetometer, a three-component magnetometer, a solar substation probe and data recording equipment, wherein the optical pump magnetometer is arranged on the magnetic cleaning platform;

the optical pump magnetometer is installed at the rotation center of the magnetic cleaning platform, the three-component magnetometer is installed at the far end of the rotating arm of the magnetic cleaning platform, the solar substation probe is installed at a position far away from the magnetic cleaning platform, and the data recording equipment is used for collecting measurement data of the optical pump magnetometer, the three-component magnetometer and the solar substation probe.

Optionally, the system further includes a data processing apparatus, the data processing apparatus is connected to the data recording device, and the following modules are embedded in the data processing apparatus:

a first calculation module configured to calculate according to formula H_HeadingError＝H_test-H_referenceCalculate H_HeadingErrorWherein H is_testIs the output of the optical pumping magnetometer, H_referenceIs the output of the diurnal variation probe;

a second calculation module configured to calculate the matrix B according to the following formula:

B＝[cos x,cos y,cos z,cos² x,cos² y,cos² z,cos x cos y,cos x cos z,cos y cos z]^T

wherein v is_x,v_y,v_zIs the output of the three-component magnetometer on three spatial axes; and

a third calculation module configured to calculate according to formula H_{heading error}＝B^TA computes a matrix A.

OptionallyAccording to formula H_{heading error}＝B^TThe specific method for calculating the matrix A comprises the following steps: according to formula H_{heading error}＝B^TAnd A, estimating a matrix A by using a recursive least square method.

The method and the system for calibrating the probe steering error magnetic interference of the optical pump magnetometer can eliminate the influence caused by the probe steering error in the aeromagnetic compensation system during turning flight.

Drawings

FIG. 1 is a schematic flow chart of a method for calibrating magnetic interference of a probe steering error of an optical pumping magnetometer according to a first embodiment;

FIG. 2 is a schematic structural diagram of a system for calibrating magnetic interference of a probe steering error of an optical pumping magnetometer according to a first embodiment;

fig. 3 is a schematic block diagram of a method for automatically evaluating the calibration quality of the aeromagnetic compensation according to the second embodiment.

Detailed Description

Example one

As shown in fig. 1, a method for calibrating a magnetic interference of a probe steering error of an optical pumping magnetometer according to the present embodiment generally includes:

s1, selecting a proper calibration site, wherein the site is required to be selected within a range of about 50m to avoid existence of high-voltage wires, power converters, high-power radio-frequency radiation sources or ferromagnetic substances with larger volume, and the like, the horizontal gradient in the site is less than 1nT/m, and the calibration site is used for arranging the magnetic cleaning platform and the solar substation probe;

step S2, installing an optical pump magnetometer at the rotation center of the magnetic cleaning platform, installing a three-component magnetometer at the far end of the rotating arm of the magnetic cleaning platform, and installing a probe of the solar substation in a field far away from the magnetic cleaning platform;

step S3, enabling the magnetic cleaning platform to rotate 360 degrees, and controlling the optical pump magnetometer to rotate around the three axes of the optical pump magnetometer when a certain axis of the optical pump magnetometer faces to the east, south, west and north directions in the rotating process so as to simulate the rolling, pitching and yawing actions of the airplane in the east, south, west and north directions;

step S4, constructing matrix H_HeadingErrorAnd matrix B:

wherein H_HeadingError＝H_test-H_reference，H_testIs the output of the optical pumping magnetometer, H_referenceIs the output of the diurnal variation probe;

B＝[cos x,cos y,cos z,cos² x,cos² y,cos² z,cos x cos y,cos x cos z,cos y cos z]^Twherein, in the step (A),

v_x,v_y,v_zis the output of the three-component magnetometer on three spatial axes;

step S5, according to formula H_{heading error}＝B^TAnd A, estimating a matrix A by using a recursive least square method, and completing the calibration of the magnetic interference of the steering error of the probe of the optical pump magnetometer.

During actual flight turning, according to formula H_{heading error}＝B^TA, calculating output H generated by the steering error of the aircraft probe by using the estimated matrix A_{heading error}And subtracting the measured total field data to obtain a geomagnetic field value without the magnetic interference of the airplane platform, and then carrying out the next airplane magnetic interference compensation.

The principle of the method for calibrating the magnetic interference of the probe steering error of the optical pump magnetometer is as follows:

optical pumping magnetometer, regardless of the element (caesium, rubidium, potassium or helium) used, and regardless of the use thereofIn which mechanism (self-excited, locked oscillator) the frequency of its output depends to some extent on the direction of the magnetometer, which results in a steering error that is related to the relative position between the optical axis and the earth magnetic field. In order to measure the relative change in spatial position between the optical axis and the earth magnetic field, it can be measured using a three-component magnetometer, and the measured values are converted into cos x, cos y, cos z, where cos x, cos y, cos z satisfy equation (1). Wherein v is_x,v_y,v_zAre the measurements of a three-component magnetometer on three spatial axes.

The relationship between the steering difference and the measured value of the three-component magnetometer can be represented by a function f (cos x, cos y, cos z). In aeromagnetic measurements, the frequencies of interest are low, so a second order taylor expansion is performed for the function f (cos x, cos y, cos z). And due to cos² x+cos² y+cos²When z is 1, the final formula (2) containing 9 unknown coefficients can be obtained by simplification.

So far, the establishment of a mathematical model about the steering difference of the helium optical pump magnetometer is finished. The corresponding calibration scheme is that the optical pumping solid magnetometer is fixed at a point, the spatial position of the optical pumping solid magnetometer is guaranteed not to change, the optical pumping solid magnetometer rotates 360 degrees, and measurement data output by the optical pumping solid magnetometer is a superposition value of steering difference and daily variation.

In order to remove the influence caused by the daily variation, a daily variation detection station is erected at a remote place, the measured value of the optical pump magnetometer and the daily variation value are synchronously collected by using data collection equipment, and the steering difference is obtained by subtracting the daily variation from the measured value of the optical pump, so that a linear equation set is established. Equation (2) can be abbreviated as:

H_{heading error}＝B^TA (3)

wherein, B ═ cos x, cos y, cos z, cos² x,cos² y,cos² z,cos x cos y,cos x cos z,cos y cos z]^T

A＝[k₁,k₂,k₃,k₄,k₅,k₆,k₇,k₈,k₉]。

The embodiment also provides a system for calibrating the magnetic interference of the steering error of the probe of the optical pumping magnetometer, and as shown in fig. 2, the system comprises a magnetic cleaning platform 1, an optical pumping magnetometer 2, a three-component magnetometer 3, a solar substation probe 4 and data recording equipment 5;

optical pump magnetometer 2 is installed 6 departments in the rotation center of the clean platform of magnetism 1, three-component magnetometer 3 is installed the distal end of the clean platform of magnetism 1 swinging boom, the clean platform of magnetism 1 position is kept away from in the daily change station probe 4, data recording equipment 5 is used for gathering the measured data of optical pump magnetometer 2, three-component magnetometer 3 and daily change station probe 4.

The system further comprises a data processing device, the data processing device is connected with the data recording equipment 5, and the following modules are embedded in the data processing device:

a first calculation module configured to calculate according to formula H_HeadingError＝H_test-H_referenceCalculate H_HeadingErrorWherein H is_testIs the output of the optical pumping magnetometer, H_referenceIs the output of the diurnal variation probe;

a second calculation module configured to calculate the matrix B according to the following formula:

B＝[cos x,cos y,cos z,cos² x,cos² y,cos² z,cos x cos y,cos x cos z,cos y cos z]^T

wherein v is_x,v_y,v_zIs the output of the three-component magnetometer on three spatial axes; and

a third calculation module configured to calculate according to formula H_{heading error}＝B^TAnd A, estimating a matrix A by using a recursive least square method.

The calibration system for the magnetic interference of the steering error of the probe of the optical pump magnetometer can be used for realizing the calibration of the magnetic interference of the steering error of the probe of the optical pump magnetometer according to the steps of the calibration method for the magnetic interference of the steering error of the probe of the optical pump magnetometer.

Example two

The embodiment provides an automatic evaluation method for aeromagnetic compensation calibration quality, which can be used for automatically evaluating the calibration quality of the optical pump magnetometer probe steering error magnetic interference calibration method in the first embodiment.

Firstly, a three-component magnetometer and a total field magnetometer (namely an optical pump magnetometer) are required to be installed on an airplane, and then the airplane can finish plane flight in four orthogonal directions (such as north, east, south and west);

the principle of the automatic evaluation method for the aeromagnetic compensation calibration quality is shown in fig. 3, and the method specifically comprises the following steps:

step S1, according to the formulaObtaining the clustering center of the flat flying ring as c_sCluster data ofWherein, a_iIs the total X and Y components of the three-component magnetometer output,is the data (heading s) of each type obtained by the k-means algorithm, representing the scalar version of the earth's magnetic field H corresponding to the ith sample point of the heading s,indicating the heading angle corresponding to the ith sampling point of the heading s,representing the inclination angle of the geomagnetic field corresponding to the ith sampling point of the course s, wherein m represents the number of courses contained in the flat flying ring, and for a standard flying ring, m is 4, and if the flying ring contains a plurality of courses, m is equal to the number of courses actually contained in the flat flying ring;

D_sclustering of sampled data representing heading s, n_sRepresents D_sThe number of sample points that are involved,is D_sData corresponding to the ith sampling point;

c_sthe K-means algorithm obtains the clustering center, and the K-means algorithm is optimizedD is the set of all s clusters;

step S2, the flying circle D_sDeleting the turning data far away from the clustering center to obtain effective clustering data of different courses of the flat flying ringWherein l_sAnd r_sRespectively representing the number of deleted sampling points at two ends of the course s, wherein the specific deletion method comprises the following steps: setting a threshold for Euler distance, and comparing the distance c_sDeleting data with Euler distance exceeding threshold;

step S3, according to the formulaObtaining a Gaussian mixture model corresponding to each course of the flat flying ring, wherein p (b)^s|G_s) Denotes the Gaussian mixture density, b^sElement (1) ofRepresenting the combination of X, Y and Z three-component magnetic field characteristics of the output of a three-component magnetometer in a rectangular spatial coordinate system, X representing a direction parallel to the transverse axis of the platform, Y representing a direction parallel to the longitudinal axis of the platform, Z representing a direction perpendicular to the horizontal plane, G_sThe parameters of the gaussian model are represented by,according to the formulaConstructing a likelihood function, estimating G using EM algorithm_s，Is that the heading s satisfies the constraintK represents the number of gaussian distributions,andrespectively is the mean and covariance matrix of the jth Gaussian distribution of the course s; it should be noted that the number of the headings included in the flat flying ring may be four, or may not be four, and is usually four, the step S3 is to obtain the gaussian mixture model corresponding to each heading of the flat flying ring, and as long as the headings corresponding to all the obtained gaussian mixture models include the heading included in the FOM maneuvering ring to be calculated, all the posterior probabilities can be calculated according to the existing gaussian mixture model to obtain which gaussian mixture model a certain heading (where a clustering algorithm is applied to separate different heading data) in the FOM maneuvering ring corresponds, and then the flat flying part corresponding to the heading is determined, and then the maneuvering part is determined;

step S4, according to the formulaObtaining the clustering center of FOM calibration circle as c_sCluster data of

Step S5, calibrating FOM to circle D_sDeleting the turning data far away from the clustering center to obtain effective clustering data of FOM calibration circles with different courses

Step S6, according to the formulaCalculating posterior probabilityThe purpose of step S6 is to calculate which Gaussian mixture model belongs to, hereThe magnetic field data of a FOM motor coil (also called FOM calibration coil) in a certain direction;

step S7, will satisfyAs maneuver data for different headings of the calibration circle, wherein T_hIs a preset threshold value;

and step S8, calculating the sum of the peak value and the peak value of the obtained maneuvering data, and taking the sum as the value of the compensation effect evaluation index FOM of the calibration loop.

Wherein, different course directions and different sampling points correspond to each otherThe values of the magnetic field are equal, the geomagnetic field inclination angles corresponding to different courses and different sampling points are differentAre equal in value.

According to the automatic evaluation method of the aeromagnetic compensation calibration quality, according to the characteristics of the data of the horizontal flight state of the aeroplatform, a Gaussian Mixture Model (GMM) Model is utilized to identify the data section of the aeroplatform in the horizontal flight state at each course, so as to obtain the data section of the aeroplatform in the maneuvering state at each course, and the index FOM for evaluating the compensation effect of the calibration circle is calculated according to the data of the maneuvering state, so that the automatic evaluation of the probe steering error magnetic interference calibration quality of the optical pump magnetometer is realized.

In both embodiments, the data processing device 6 may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed by a computer, cause the computer to perform, in whole or in part, the procedures or functions described in accordance with the embodiments of the application. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

Those skilled in the art will further appreciate that the data processing apparatus described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the functions of the data processing apparatus are performed in either hardware or software depending on the particular application and design constraints imposed on the technical solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It will be understood by those skilled in the art that all or part of the steps in the method for implementing the above embodiments may be implemented by a program, and the program may be stored in a computer-readable storage medium, where the storage medium is a non-transitory medium, such as a random access memory, a read only memory, a flash memory, a hard disk, a solid state disk, a magnetic tape (magnetic tape), a floppy disk (floppy disk), an optical disk (optical disk), and any combination thereof.

The above description is only for the preferred embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.