Atomic magnetometer course error dynamic compensation method and atomic magnetometer

Abstract

The invention provides an atomic magnetometer heading error dynamic compensation method and an atomic magnetometer, and the method comprises the steps: 1, placing the atomic magnetometer in a magnetic field environment with a known direction and stable intensity, achieving the calibration test of an atomic spin heading error through the adjustment of the attitude angle of the magnetometer, and obtaining the atomic spin error magnetic field intensity BE through calculation; 2, an alternating current magnetic field # imgabs0 # parallel to the driving light direction is actively applied to the atom magnetometer, the response characteristic of the atom magnetometer to the alternating current magnetic field # imgabs1 # is the same as the response characteristic of the atom spin error magnetic field # imgabs2 #, namely, B = B0 + BE.cos theta + BAC. Cos theta, and the heading error dynamic compensation of the atom magnetometer is achieved through the magnetic field Bf with the frequency of f detected by the atom magnetometer, b is the total magnetic field detected by the atom magnetometer, B0 is the environmental magnetic field intensity in the geomagnetic environment, and theta is the included angle between the driving light and the environmental magnetic field. By applying the technical scheme of the invention, the technical problem that high sensitivity and low course error are difficult to take into account along with the gradual reduction of the volume of the atom magnetometer in the prior art is solved.

Description

Technical Field

[0001] The invention relates to the technical field of atomic magnetometers, and in particular to a method for dynamically compensating an atomic magnetometer heading error and an atomic magnetometer. Background Art

[0002] Atomic magnetometers measure the magnitude of magnetic fields through the Larmor precession of atomic spins in an external magnetic field. They have the characteristics of high sensitivity, insensitivity to magnetic field direction, and stable scale factor, and have been widely used in various magnetic field measurement fields. With the advancement of quantum control technology, the static noise of atomic magnetometers is getting lower and lower. The heading error caused by the sensor attitude change dominated by the atomic spin nonlinear Zeeman effect and the atomic spin optical frequency shift effect has become the main reason restricting the dynamic performance of atomic magnetometers.

[0003] The traditional atomic magnetometer heading error suppression is based on the premise of low atomic spin polarization intensity, which is generally applicable to large-volume atomic magnetometers. As the volume of atomic magnetometers gradually decreases, it is difficult to achieve both high sensitivity and low heading error. Therefore, a heading error dynamic compensation method suitable for small-volume atomic magnetometers is urgently needed to meet the requirements of high sensitivity and low dynamic noise for small-volume atomic magnetometers in various dynamic application fields. Summary of the invention

[0004] The present invention provides an atomic magnetometer heading error dynamic compensation method and an atomic magnetometer, which can solve the technical problem in the prior art that it is difficult to achieve both high sensitivity and low heading error as the volume of the atomic magnetometer gradually decreases.

[0005] According to one aspect of the present invention, a method for dynamic compensation of heading error of an atomic magnetometer is provided. The method for dynamic compensation of heading error of an atomic magnetometer comprises: step 1, placing the atomic magnetometer in a magnetic field environment with a known direction and a stable intensity, realizing calibration test of atomic spin heading error by adjusting the magnetometer attitude angle, and calculating and obtaining the atomic spin error magnetic field intensity B E Step 2: Actively apply an AC magnetic field parallel to the driving light direction to the atomic magnetometer Atomic magnetometer for AC magnetic field The response characteristics of the atomic spin error magnetic field The response characteristics are the same, that is, B=B0+B E ·cosθ+B AC cosθ, the magnetic field B with frequency f detected by an atomic magnetometer f Dynamic compensation of the heading error of the atomic magnetometer is realized, where B is the total magnetic field detected by the atomic magnetometer, B0 is the ambient magnetic field intensity under the geomagnetic environment, and θ is the angle between the driving light and the ambient magnetic field.

[0006] Furthermore, step one specifically includes: placing the atomic magnetometer in a magnetic field environment with a known direction and stable strength; adjusting the direction of the atomic magnetometer driving light to be parallel to the direction of the environmental magnetic field, and recording the first atomic magnetometer magnetic field measurement output B1; adjusting the direction of the atomic magnetometer driving light to be antiparallel to the direction of the environmental magnetic field, and recording the second atomic magnetometer magnetic field measurement output B2; calculating and obtaining the atomic spin error magnetic field intensity B according to the first atomic magnetometer magnetic field measurement output B1 and the second atomic magnetometer magnetic field measurement output B2. E .

[0007] Furthermore, the atomic spin error magnetic field strength B E according to Calculate acquisition.

[0008] Furthermore, step 2 specifically includes: actively applying an alternating magnetic field parallel to the driving light direction to the atomic magnetometer Among them B AC =A·sin2πft; Real-time acquisition of the magnetic field B with a frequency of f detected by the atomic magnetometer f , according to the magnetic field B f Calculate and obtain cosθ; calculate and obtain the compensation amount based on the obtained cosθ, use the compensation amount to compensate the output of the atomic magnetometer, and filter out the high-frequency AC magnetic field through low-pass filtering The compensated atomic magnetometer output B 补偿 , realizing dynamic compensation of heading error of atomic magnetometer.

[0009] Furthermore, according to the magnetic field B f The calculation of cosθ specifically includes: magnetic field B f For B f =A f sin2πft, the magnetic field B f With the applied AC magnetic field Component B AC ·cosθ is equal, that is, B AC ·cosθ=A sin2πf ·cosθ=A f sin2πft, we get

[0010] Furthermore, the compensated atomic magnetometer output B 补偿 According to Calculated and obtained, B is the total magnetic field detected by the atomic magnetometer.

[0011] According to another aspect of the present invention, an atomic magnetometer is provided. The atomic magnetometer performs dynamic compensation for heading error by using the atomic magnetometer heading error dynamic compensation method as described above.

[0012] The technical solution of the present invention provides a method for dynamic compensation of heading error of an atomic magnetometer. The method is based on the atomic spin error model and uses the driving light direction to modulate the magnetic field to realize real-time sensing of heading error. An AC magnetic field parallel to the driving light direction is actively applied to the atomic magnetometer. Atomic magnetometer for AC magnetic field The response characteristics of the atomic spin error magnetic field The response characteristics are the same as those of the magnetic field B with a frequency of f detected by the atomic magnetometer. f Realize dynamic compensation of heading error of atomic magnetometer. This method can significantly suppress heading error caused by atomic spin nonlinear Zeeman effect and atomic spin optical frequency shift effect, and is particularly suitable for various dynamic application environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The included drawings are used to provide a further understanding of the embodiments of the present invention, which constitute a part of the specification, are used to illustrate the embodiments of the present invention, and together with the text description, explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0014] Figure 1 A flow chart of a method for dynamically compensating heading errors of an atomic magnetometer provided according to a specific embodiment of the present invention is shown. DETAILED DESCRIPTION

[0015] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0017] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0018] like Figure 1 As shown, according to a specific embodiment of the present invention, a method for dynamic compensation of heading error of an atomic magnetometer is provided, and the method for dynamic compensation of heading error of an atomic magnetometer comprises: step 1, placing the atomic magnetometer in a magnetic field environment with a known direction and a stable intensity, realizing calibration test of atomic spin heading error by adjusting the magnetometer attitude angle, and calculating and obtaining the atomic spin error magnetic field intensity B E Step 2: Actively apply an AC magnetic field parallel to the driving light direction to the atomic magnetometer Atomic magnetometer for AC magnetic field The response characteristics of the atomic spin error magnetic field The response characteristics are the same, that is, B=B0+B E ·cosθ+B AC cosθ, the magnetic field B with frequency f detected by an atomic magnetometer f Dynamic compensation of the heading error of the atomic magnetometer is realized, where B is the total magnetic field detected by the atomic magnetometer, B0 is the ambient magnetic field intensity under the geomagnetic environment, and θ is the angle between the driving light and the ambient magnetic field.

[0019] By using this configuration, a method for dynamic compensation of heading error of atomic magnetometer is provided. This method is based on the atomic spin error model and uses the driving light direction to modulate the magnetic field to achieve real-time sensing of heading error. An AC magnetic field parallel to the driving light direction is actively applied to the atomic magnetometer. Atomic magnetometer for AC magnetic field The response characteristics of the atomic spin error magnetic field The response characteristics are the same as those of the magnetic field B with a frequency of f detected by the atomic magnetometer. f Realize dynamic compensation of heading error of atomic magnetometer. This method can significantly suppress heading error caused by atomic spin nonlinear Zeeman effect and atomic spin optical frequency shift effect, and is particularly suitable for various dynamic application environments.

[0020] In the present invention, in order to obtain the atomic spin error magnetic field strength B E The first step specifically includes: placing the atomic magnetometer in a magnetic field environment with a known direction and a stable intensity; adjusting the direction of the atomic magnetometer driving light to be parallel to the direction of the environmental magnetic field, and recording the first atomic magnetometer magnetic field measurement output B1; adjusting the direction of the atomic magnetometer driving light to be antiparallel to the direction of the environmental magnetic field, and recording the second atomic magnetometer magnetic field measurement output B2; calculating and obtaining the atomic spin error magnetic field intensity B according to the first atomic magnetometer magnetic field measurement output B1 and the second atomic magnetometer magnetic field measurement output B2. E Among them, the atomic spin error magnetic field strength B E according to Calculate acquisition.

[0021] Furthermore, in the present invention, in order to realize the dynamic compensation of the heading error of the atomic magnetometer, step 2 specifically includes: actively applying an alternating magnetic field parallel to the driving light direction to the atomic magnetometer Among them B AC =A·sin2πft; Real-time acquisition of the magnetic field B with a frequency of f detected by the atomic magnetometer f , according to the magnetic field B f Calculate and obtain cosθ; calculate and obtain the compensation amount based on the obtained cosθ, use the compensation amount to compensate the output of the atomic magnetometer, and filter out the high-frequency AC magnetic field through low-pass filtering The compensated atomic magnetometer output B 补偿 , realizing dynamic compensation of heading error of atomic magnetometer.

[0022] According to the magnetic field B f The calculation of cosθ specifically includes: magnetic field B f For B f =A f sin2πft, the magnetic field B f With the applied AC magnetic field Component B AC ·cosθ is equal, that is, B AC ·cosθ=A sin2πf ·cosθ=A f sin2πft, we get

[0023] The compensated atomic magnetometer output B 补偿 According to Calculated and obtained, B is the total magnetic field detected by the atomic magnetometer.

[0024] According to another aspect of the present invention, an atomic magnetometer is provided. The atomic magnetometer performs dynamic compensation for heading error by using the atomic magnetometer heading error dynamic compensation method as described above.

[0025] By applying this configuration, an atomic magnetometer is provided, which uses the atomic magnetometer heading error dynamic compensation method as described above to dynamically compensate for the heading error. Since this method is based on the atomic spin error model, it uses the driving light direction to modulate the magnetic field to realize real-time sensing of the heading error, and finally realizes the dynamic compensation of the heading error of the atomic magnetometer. This method can significantly suppress the heading error caused by the atomic spin nonlinear Zeeman effect and the atomic spin optical frequency shift effect, and is particularly suitable for various dynamic application environments. Therefore, using this method in an atomic magnetometer can greatly improve the working performance of the atomic magnetometer.

[0026] In order to further understand the present invention, the following Figure 1 The atomic magnetometer heading error dynamic compensation method provided by the present invention is described in detail.

[0027] The nonlinear Zeeman effect of atomic spin and the optical frequency shift effect of atomic spin are the main error sources of the heading error of the atomic magnetometer. The heading error dominated by the nonlinear Zeeman effect of atomic spin and the optical frequency shift effect of atomic spin is affected by the polarized atomic spin of the driving light, which is approximately equivalent to introducing a vector magnetic field parallel to the direction of the driving light. Atomic magnetometer simultaneously responds to real ambient magnetic field and error magnetic field Since the atomic magnetometer measures the magnetic field scalar, the ambient magnetic field strength B0 in the geomagnetic environment is much greater than the error magnetic field strength B E Therefore, the actual magnetic field measurement result of the atomic magnetometer can be approximated as B = B0 + B E ·cosθ, where θ is the angle between the driving light and the ambient magnetic field.

[0028] Based on the above atomic spin error model, the present invention uses the driving light direction to modulate the magnetic field to achieve real-time sensing of heading error, and finally realizes dynamic compensation of heading error of atomic magnetometer. The specific implementation steps are as follows:

[0029] Step 1: Atomic spin heading error calibration test

[0030] From B=B0+B E ·cosθ shows that the heading error is the largest when the atomic magnetometer driving light is parallel or antiparallel to the ambient magnetic field. The atomic magnetometer is placed in a magnetic field environment with a known direction and stable strength. The calibration test of the atomic spin heading error can be achieved by adjusting the magnetometer attitude angle. The specific implementation steps are as follows:

[0031] (1.1) Place the atomic magnetometer in a magnetic field environment with known direction and stable intensity;

[0032] (1.2) Adjust the driving light direction of the atomic magnetometer to be parallel to the direction of the ambient magnetic field, and record the magnetic field measurement output B1 of the atomic magnetometer;

[0033] (1.3) Adjust the driving light direction of the atomic magnetometer to be antiparallel to the direction of the ambient magnetic field, and record the magnetic field measurement output B2 of the atomic magnetometer;

[0034] (1.4) Calculate the atomic spin error magnetic field strength

[0035] Step 2: Dynamic compensation of heading error of atomic magnetometer

[0036] In actual application environment, the angle between the atomic magnetometer driving light and the ambient magnetic field changes dynamically. An AC magnetic field parallel to the driving light direction is actively applied to the atomic magnetometer. Among them B AC =A·sin2πft, then the atomic magnetometer The response characteristics and The same, that is, B=B0+B E ·cosθ+B AC ·cosθ. The magnetic field B with frequency f detected by the atomic magnetometer f To achieve dynamic compensation of heading error, the specific implementation steps are as follows:

[0037] (2.1) Actively apply an AC magnetic field parallel to the driving light direction to the atomic magnetometer Among them B AC =A·sin2πft;

[0038] (2.2) Real-time calculation of the magnetic field B with frequency f detected by the atomic magnetometer f =A f sin2πft, we get

[0039]

[0040] (2.3) Compensate the output of the atomic magnetometer and filter out the high-frequency AC magnetic field through a low-pass filter get: At this time, the compensated atomic magnetometer outputs B 补偿 It is the same as the ambient magnetic field B0 which is not affected by the heading error, thus realizing dynamic compensation of the heading error of the atomic magnetometer.

[0041] The beneficial effects of the present invention compared with the prior art are as follows:

[0042] The traditional atomic magnetometer heading error suppression is based on the premise of low atomic spin polarization intensity, which is generally applicable to large-volume atomic magnetometers. As the volume of atomic magnetometers gradually decreases, it is difficult to achieve both high sensitivity and low heading error.

[0043] The present invention is based on the atomic spin error mechanism, uses the driving light direction to modulate the magnetic field to achieve real-time sensing of the heading error, and finally realizes dynamic compensation of the heading error of the atomic magnetometer. The present invention can significantly reduce the heading error of the atomic magnetometer, can take into account both high sensitivity and low dynamic noise, and is suitable for various dynamic application environments, especially for small-volume atomic magnetometers.

[0044] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0045] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for dynamic compensation of heading error of an atomic magnetometer, characterized in that: The atomic magnetometer heading error dynamic compensation method comprises: Step 1: Place the atomic magnetometer in a magnetic field environment with known direction and stable strength, and calibrate the atomic spin heading error by adjusting the magnetometer attitude angle to calculate the atomic spin error magnetic field strength B. E ; Step 2: Actively apply an AC magnetic field parallel to the driving light direction to the atomic magnetometer The atomic magnetometer is sensitive to AC magnetic fields The response characteristics of the atomic spin error magnetic field The response characteristics are the same, that is, B=B0+B E ·cosθ+B AC cosθ, the magnetic field B with frequency f detected by the atomic magnetometer f Dynamic compensation of the heading error of the atomic magnetometer is realized, where B is the total magnetic field detected by the atomic magnetometer, B0 is the ambient magnetic field intensity under the geomagnetic environment, and θ is the angle between the driving light and the ambient magnetic field.

2. The method for dynamic compensation of heading error of an atomic magnetometer according to claim 1, characterized in that: The step 1 specifically includes: Place the atomic magnetometer in a magnetic field environment with known direction and stable strength; Adjust the driving light direction of the atomic magnetometer to be parallel to the direction of the ambient magnetic field, and record the first atomic magnetometer magnetic field measurement output B1; Adjust the driving light direction of the atomic magnetometer to be anti-parallel to the direction of the ambient magnetic field, and record the magnetic field measurement output B2 of the second atomic magnetometer; The atomic spin error magnetic field intensity B is calculated and obtained according to the magnetic field measurement output B1 of the first atomic magnetometer and the magnetic field measurement output B2 of the second atomic magnetometer E .

3. The method for dynamic compensation of heading error of an atomic magnetometer according to claim 2, characterized in that: The atomic spin error magnetic field strength B E according to Calculate acquisition.

4. The method for dynamic compensation of heading error of an atomic magnetometer according to claim 2, characterized in that: The step 2 specifically includes: Actively apply an AC magnetic field parallel to the driving light direction to the atomic magnetometer Among them B AC =A·sin2πft; Real-time acquisition of the magnetic field B with a frequency of f detected by the atomic magnetometer f , according to the magnetic field B f Calculate and obtain cosθ; The compensation amount is calculated based on the obtained cosθ, and the output of the atomic magnetometer is compensated by the compensation amount, and the high-frequency AC magnetic field is filtered out by low-pass filtering. The compensated atomic magnetometer output B 补偿 , realizing dynamic compensation of heading error of atomic magnetometer.

5. The method for dynamic compensation of heading error of an atomic magnetometer according to claim 4, characterized in that: According to the magnetic field B f The calculation to obtain cosθ specifically includes: the magnetic field B f For B f =A f sin2πft, the magnetic field B f With the applied AC magnetic field Component B AC ·cosθ is equal, that is, B AC ·cosθ=A sin2πf ·cosθ=A f sin2πft, we get 6. The method for dynamic compensation of heading error of an atomic magnetometer according to claim 5, characterized in that: The compensated atomic magnetometer output B 补偿 According to Calculated and obtained, B is the total magnetic field detected by the atomic magnetometer.

7. An atomic magnetometer, characterized in that: The atomic magnetometer performs dynamic compensation for heading error using the atomic magnetometer heading error dynamic compensation method according to any one of claims 1 to 6.

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