Atomic magnetometer heading error dynamic compensation method and atomic magnetometer

Abstract

The application provides an atomic magnetometer heading error dynamic compensation method and an atomic magnetometer. E ; step two, an alternating current magnetic field parallel to the driving light direction is actively applied to the atomic magnetometer; the response characteristics of the atomic magnetometer to the alternating current magnetic field are the same as the response characteristics of the atomic spin error magnetic field, that is, B=B0+B E ·cosθ+B AC ·cosθ; the frequency f of the magnetic field B f detected by the atomic magnetometer is used to realize atomic magnetometer heading error dynamic compensation, wherein B is the total magnetic field detected by the atomic magnetometer, B0 is the environmental magnetic field intensity in the geomagnetic environment, and θ is the included angle between the driving light and the environmental magnetic field. The technical scheme of the application is used to solve the technical problem that high sensitivity and low heading error are difficult to be considered together with the gradual reduction of the volume of the atomic magnetometer in the prior art.

Description

Technical Field

[0001] This invention relates to the field of atomic magnetometer technology, and in particular to a dynamic compensation method for heading error of an atomic magnetometer and an atomic magnetometer. Background Technology

[0002] Atomic magnetometers measure the magnitude of magnetic fields by utilizing the Larmor precession of atomic spins in an external magnetic field. They are characterized by high sensitivity, insensitivity to magnetic field direction, and stable scaling factors, and have been widely used in various fields of magnetic field measurement. With advancements in quantum control technology, the static noise of atomic magnetometers is decreasing. However, heading errors caused by sensor attitude changes, dominated by nonlinear Zeeman effects of atomic spins and optical frequency shift effects, have become the main factor limiting the dynamic performance of atomic magnetometers.

[0003] Traditional atomic magnetometer heading error suppression relies on low atomic spin polarization and is generally suitable for large-volume atomic magnetometers. However, as the size of atomic magnetometers decreases, achieving both high sensitivity and low heading error becomes increasingly difficult. Therefore, a dynamic heading error compensation method suitable for small-volume atomic magnetometers is urgently needed to meet the requirements of high sensitivity and low dynamic noise in various dynamic applications. Summary of the Invention

[0004] This invention provides a dynamic compensation method for heading error of an atomic magnetometer 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 size 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 includes: Step 1, placing the atomic magnetometer in a magnetic field environment with known direction and stable intensity, calibrating and testing the atomic spin heading error by adjusting the attitude angle of the magnetometer, and calculating and obtaining the magnetic field strength B of the atomic spin error. E Step two: Actively apply an alternating magnetic field parallel to the direction of the driving light to the atomic magnetometer. Atomic magnetometer for alternating magnetic fields Response characteristics and 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 for heading error of atomic magnetometer is achieved, where B is the total magnetic field detected by atomic magnetometer, B0 is the intensity of ambient magnetic field under geomagnetic environment, and θ is the angle between driving light and ambient magnetic field.

[0006] Further, step one specifically includes: placing the atomic magnetometer in a magnetic field environment with a known direction and stable intensity; adjusting the direction of the atomic magnetometer's driving light to be parallel to the direction of the ambient magnetic field, and recording the magnetic field measurement output B1 of the first atomic magnetometer; adjusting the direction of the atomic magnetometer's driving light to be parallel to the direction of the ambient magnetic field, and recording the magnetic field measurement output B2 of the second atomic magnetometer; calculating the atomic spin error magnetic field strength B based on the magnetic field measurement outputs B1 and B2 of the first and second atomic magnetometers. E .

[0007] Furthermore, the atomic spin error magnetic field strength B E according to Calculated and obtained.

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

[0009] Furthermore, according to magnetic field B f The calculation of cosθ specifically includes: magnetic field B f For B f =A f sin2πft, magnetic field B f With applied alternating magnetic field Component B AC ·cosθ is equal, that is, B AC ·cosθ=Asin2πf·cosθ=A f sin2πft, we can find

[0010] Furthermore, the compensated atomic magnetometer output B 补偿 According to The calculation yields B, which represents the total magnetic field detected by the atomic magnetometer.

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

[0012] The present invention provides a method for dynamic compensation of heading error in an atomic magnetometer. This method is based on an atomic spin error model and utilizes a magnetic field modulated by the direction of the driving light to achieve real-time sensing of heading error. An alternating magnetic field parallel to the direction of the driving light is actively applied to the atomic magnetometer. Atomic magnetometer for alternating magnetic fields Response characteristics and atomic spin error magnetic field The response characteristics are the same, and the magnetic field B with frequency f is detected by an atomic magnetometer. f Achieving dynamic compensation for heading errors in atomic magnetometers. This method can significantly suppress heading errors caused by atomic spin nonlinearity Zeeman effect and atomic spin optical frequency shift effect, and is particularly suitable for various dynamic application environments. Attached Figure Description

[0013] The accompanying drawings, which form part of this specification, are provided to further illustrate embodiments of the invention and, together with the textual description, explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0014] Figure 1 A flowchart of a dynamic compensation method for heading error of an atomic magnetometer provided according to a specific embodiment of the present invention is shown. Detailed Implementation

[0015] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0017] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0018] like Figure 1 As shown, a dynamic compensation method for the heading error of an atomic magnetometer is provided according to a specific embodiment of the present invention. This method includes: Step 1, placing the atomic magnetometer in a magnetic field environment with known direction and stable intensity, calibrating and testing the atomic spin heading error by adjusting the magnetometer's attitude angle, and calculating and obtaining the atomic spin error magnetic field strength B. E Step two: Actively apply an alternating magnetic field parallel to the direction of the driving light to the atomic magnetometer. Atomic magnetometer for alternating magnetic fields Response characteristics and 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 for heading error of atomic magnetometer is achieved, where B is the total magnetic field detected by atomic magnetometer, B0 is the intensity of ambient magnetic field under geomagnetic environment, and θ is the angle between driving light and ambient magnetic field.

[0019] This configuration provides a dynamic compensation method for heading error of an atomic magnetometer. Based on an atomic spin error model, this method utilizes a magnetic field modulated by the direction of the driving light to achieve real-time sensing of heading error, actively applying an alternating magnetic field parallel to the direction of the driving light to the atomic magnetometer. Atomic magnetometer for alternating magnetic fields Response characteristics and atomic spin error magnetic field The response characteristics are the same, and the magnetic field B with frequency f is detected by an atomic magnetometer. f Achieving dynamic compensation for heading errors in atomic magnetometers. This method can significantly suppress heading errors caused by atomic spin nonlinearity Zeeman effect and atomic spin optical frequency shift effect, and is particularly suitable for various dynamic application environments.

[0020] In this invention, in order to obtain the atomic spin error magnetic field strength B E Step one specifically includes: placing the atomic magnetometer in a magnetic field environment with known direction and stable intensity; adjusting the direction of the atomic magnetometer's driving light to be parallel to the direction of the ambient magnetic field, and recording the magnetic field measurement output B1 of the first atomic magnetometer; adjusting the direction of the atomic magnetometer's driving light to be parallel to the direction of the ambient magnetic field, and recording the magnetic field measurement output B2 of the second atomic magnetometer; calculating the atomic spin error magnetic field strength B based on the magnetic field measurement outputs B1 and B2 of the first and second atomic magnetometers. E Among them, the atomic spin error magnetic field strength B E according to Calculated and obtained.

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

[0022] Among them, according to magnetic field B f The calculation of cosθ specifically includes: magnetic field B f For B f =A f sin2πft, magnetic field B f With applied alternating magnetic field Component B AC ·cosθ is equal, that is, B AC ·cosθ=Asin2πf·cosθ=A f sin2πft, we can find

[0023] The compensated atomic magnetometer output B 补偿 According to The calculation yields B, which represents the total magnetic field detected by the atomic magnetometer.

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

[0025] This configuration provides an atomic magnetometer that utilizes the aforementioned dynamic heading error compensation method. Because this method is based on an atomic spin error model and uses the driving light direction to modulate the magnetic field to achieve real-time sensing of the heading error, it ultimately achieves dynamic heading error compensation for the atomic magnetometer. This method can significantly suppress heading errors caused by atomic spin nonlinearity Zeeman effect and atomic spin optical frequency shift effect, making it particularly suitable for various dynamic application environments. Therefore, applying this method to an atomic magnetometer can greatly improve its performance.

[0026] To gain a further understanding of the present invention, the following description is provided in conjunction with... Figure 1 The present invention provides a detailed description of the dynamic compensation method for heading error of an atomic magnetometer.

[0027] The nonlinear Zeeman effect of atomic spin and the frequency shift effect of atomic spin are the main sources of heading error in atomic magnetometers. The heading error, dominated by these two effects, is influenced by the spin of the driving light-polarized atoms, which approximately equivalently introduces a vector magnetic field parallel to the direction of the driving light. Atomic magnetometers simultaneously respond to real-world magnetic fields With error magnetic field Since atomic magnetometers measure magnetic field scalars, the ambient magnetic field strength B0 in a geomagnetic environment is much greater than the error magnetic field strength B. E Therefore, the actual magnetic field measurement result of an 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] This invention, based on the aforementioned atomic spin error model, utilizes the driving light direction to modulate the magnetic field to achieve real-time sensing of heading error, ultimately realizing dynamic compensation for the heading error of the atomic magnetometer. The specific implementation steps are as follows:

[0029] Step 1: Atomic Spin Heading Error Calibration Test

[0030] From B = B0 + B E According to cosθ, the heading error is greatest when the driving light of the atomic magnetometer is parallel or antiparallel to the ambient magnetic field. By placing the atomic magnetometer in a magnetic field environment with known direction and stable strength, the atomic spin heading error can be calibrated and tested by adjusting the magnetometer's 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 strength;

[0032] (1.2) Adjust the direction of the driving light 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 direction of the driving light of the atomic magnetometer to be parallel to the direction of the ambient magnetic field, and record the magnetic field measurement output B2 of the atomic magnetometer;

[0034] (1.4) The atomic spin error magnetic field strength is calculated.

[0035] Step 2: Dynamic Compensation for Atomic Magnetometer Heading Error

[0036] The dynamic change of the angle between the driving light of the atomic magnetometer and the ambient magnetic field in a practical application environment. An alternating magnetic field parallel to the direction of the driving light is actively applied to the atomic magnetometer. Among them B AC =A·sin2πft, then the atomic magnetometer is... Response characteristics and They are the same, that is, B = B0 + B E ·cosθ+B AC •cosθ. The magnetic field B with frequency f detected using an atomic magnetometer. f The specific steps for achieving dynamic compensation for heading errors are as follows:

[0037] (2.1) An alternating magnetic field parallel to the driving light direction is actively applied 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 point, the compensated atomic magnetometer outputs B. 补偿 The magnetic field B0 is the same as the ambient magnetic field that is not affected by the heading error, thus realizing dynamic compensation for the heading error of the atomic magnetometer.

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

[0042] Traditional atomic magnetometers rely on low spin polarization of atoms to suppress heading errors, and are generally suitable for large-volume atomic magnetometers. As the size of atomic magnetometers gradually decreases, it becomes difficult to simultaneously achieve high sensitivity and low heading error.

[0043] This invention is based on the atomic spin error mechanism and utilizes the direction of the driving light to modulate the magnetic field to achieve real-time sensing of heading error, ultimately realizing dynamic compensation for the heading error of an atomic magnetometer. This invention can significantly reduce the heading error of an atomic magnetometer, balancing high sensitivity with low dynamic noise, and is suitable for various dynamic application environments, especially for small-volume atomic magnetometers.

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

[0045] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of dynamic compensation of heading errors in atomic magnetometer, characterized in that, The atomic magnetometer heading error dynamic compensation method comprises the following steps: Step one, place the atomic magnetometer in a known direction, stable magnetic field environment, by adjusting the magnetometer attitude angle to achieve atomic spin heading error calibration test, to calculate the atomic spin error magnetic field strength ; Step two, actively impose an AC magnetic field parallel to the driving light direction on the atomic magnetometer , the response characteristics of the atomic magnetometer to the AC magnetic field are the same as the response characteristics of the atomic spin error magnetic field , that is , wherein, is the total magnetic field detected by the atomic magnetometer, is the environmental magnetic field strength in the geomagnetic environment, is the angle between the driving light and the environmental magnetic field; the frequency of the magnetic field detected by the atomic magnetometer is used to realize dynamic compensation of the atomic magnetometer heading error; The step two specifically comprises the following steps: Applying an ac magnetic field parallel to the direction of the drive light to an atomic magnetometer wherein ; The frequency of the magnetic field detected by the atomic magnetometer is acquired in real time , and the magnetic field is calculated and acquired according to the magnetic field ;​ According to the acquisition The compensation amount is calculated, the atomic magnetometer output is compensated by using the compensation amount, and the high-frequency alternating magnetic field is filtered out by low-pass filtering The compensated atomic magnetometer output is obtained The dynamic compensation of the heading error of the atomic magnetometer is realized.

2. The atomic magnetometer heading error dynamic compensation method of claim 1, wherein, The step one specifically comprises the following steps: The atomic magnetometer is placed in a magnetic field environment with a known direction and stable intensity. Adjusting the direction of the driving light of the atomic magnetometer to be parallel to the direction of the ambient magnetic field, and recording the output of the first atomic magnetometer for measuring the magnetic field ; Adjusting the direction of the driving light of the atomic magnetometer to be anti-parallel to the direction of the ambient magnetic field, and recording the output of the second atomic magnetometer for measuring the magnetic field ; from the first atomic magnetometer magnetic field measurement output and the second atomic magnetometer magnetic field measurement output computing an atomic spin error magnetic field strength .

3. The atomic magnetometer heading error dynamic compensation method of claim 2, wherein, The atomic spin error magnetic field strength According to Computed acquisition.

4. The atomic magnetometer heading error dynamic compensation method of claim 1, wherein, According to the magnetic field Computational acquisition Specifically comprising: the magnetic field For , the magnetic field With the applied alternating magnetic field Component Equal, that is , get .

5. The atomic magnetometer heading error dynamic compensation method of claim 4, wherein, Compensated atomic magnetometer output may be calculated according to may be calculated according to the total magnetic field probed by the atomic magnetometer.

6. An atomic magnetometer, characterized in that, The atomic magnetometer utilizes the atomic magnetometer heading error dynamic compensation method according to any one of claims 1 to 5 for dynamic compensation of heading error.

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