Method and device for calibrating atomic magnetometer, computer device and storage medium

Abstract

The application relates to a kind of atomic magnetometer calibration method, device, computer equipment, storage medium and computer program product.The method comprises the following steps: the environment parameter of the working environment of target atomic magnetometer is set as the environment parameter of large magnetic field working environment, and the working mode of target atomic magnetometer is set as absolute measurement mode, the target coil in target atomic magnetometer is calibrated, and the coil constant of target coil is obtained;The environment parameter of the working environment of target atomic magnetometer is set as the environment parameter of near zero magnetic working environment, and the working mode of target atomic magnetometer is set as relative measurement mode, based on the coil constant of target coil, target atomic magnetometer is calibrated, and the response coefficient of target atomic magnetometer is obtained;Response coefficient is used to support target atomic magnetometer to measure extremely weak magnetic field.The calibration error of atomic magnetometer can be reduced by using the method.

Description

Technical Field

[0001] This application relates to the field of quantum precision measurement technology, and in particular to a calibration method, apparatus, computer equipment, storage medium and computer program product for an atomic magnetometer. Background Technology

[0002] With the development of quantum precision measurement technology, the measurement sensitivity of atomic magnetometers has been continuously improved, becoming comparable to that of superconducting quantum interference devices (SQUIDs), which have the highest sensitivity in traditional magnetic field measurement. Due to their advantages of portability, low cost, and small size, atomic magnetometers are widely used in mineral exploration, magnetic anomaly measurement, geomagnetic field detection, atomic and molecular physics research, and biomagnetic field detection. Among different types of atomic magnetometers, spin-exchange relaxation-free (SERF) atomic magnetometers currently have the highest sensitivity and are considered an important means of detecting extremely weak magnetic fields that can rival SQUID magnetometers in the future. They have received widespread attention in biomagnetic field detection (such as magnetic resonance imaging of the heart and brain). SERF atomic magnetometers are essentially vector-type relative magnetometers operating in a zero-field environment; their measurement accuracy and sensitivity depend on the calibration of their magnetic field response coefficient.

[0003] The existing calibration method for atomic magnetometers is as follows: First, a standard coil (such as a Helmholtz coil) is calibrated using other magnetometers, such as fluxgate magnetometers or optically pumped magnetometers, to obtain the coil's response coefficient. Then, the atomic magnetometer is placed in a standard magnetic field provided by the standard coil and a magnetically shielded environment, with its position and sensitive axis aligned with the magnetometer used for calibration. A certain current is applied to the standard coil, and the strength of the magnetic field provided at this time is calculated using the response coefficient of the standard coil. Then, based on the output of the atomic magnetometer, the response relationship between the magnetic field and the atomic magnetometer output is given, thus calibrating the atomic magnetometer. The calibrated atomic magnetometer is then used for each subsequent magnetic field measurement.

[0004] However, when calibrating an atomic magnetometer using a standard coil, it is difficult to ensure that the positions and sensitive axis directions of other magnetometers used for standard coil calibration are completely consistent with those of the atomic magnetometer being calibrated. This results in positional and directional errors, leading to calibration errors. Therefore, existing atomic magnetometer calibration methods have relatively large errors. Summary of the Invention

[0005] Therefore, it is necessary to provide a calibration method, apparatus, computer equipment, computer-readable storage medium, and computer program product for an atomic magnetometer that can reduce errors, in order to address the above-mentioned technical problems.

[0006] Firstly, this application provides a calibration method for an atomic magnetometer. The method includes:

[0007] The environmental parameters of the target atomic magnetometer are set to those of a large magnetic field working environment, and the working mode of the target atomic magnetometer is set to absolute measurement mode. The target coil located inside the target atomic magnetometer is calibrated to obtain the coil constant of the target coil.

[0008] The environmental parameters of the target atomic magnetometer are set to those of a near-zero magnetic operating environment, and the operating mode of the target atomic magnetometer is set to a relative measurement mode. Based on the coil constant of the target coil, the target atomic magnetometer is calibrated to obtain the response coefficient of the target atomic magnetometer. The response coefficient is used to support the target atomic magnetometer in measuring extremely weak magnetic fields.

[0009] In one embodiment, setting the environmental parameters of the target atomic magnetometer's operating environment to those of a large magnetic field operating environment, and setting the operating mode of the target atomic magnetometer to an absolute measurement mode, includes:

[0010] In response to the magnetometer measurement command, the environmental parameters of the target atomic magnetometer's operating environment are set to those of a large magnetic field operating environment, and the operating mode of the target atomic magnetometer is set to absolute measurement mode; the magnetometer measurement command is used to instruct the target atomic magnetometer to perform magnetic field measurement.

[0011] In one embodiment, calibrating the target coil located within the target atomic magnetometer to obtain the coil constant of the target coil includes:

[0012] Determine the frequency of the modulation signal of the target atomic magnetometer, and apply the modulation signal of the frequency to the target coil located within the target atomic magnetometer;

[0013] The current of the target coil is scanned to determine the current value of the target atomic magnetometer at two zero crossings in response to the static magnetic field; the static magnetic field is the magnetic field generated by the current of the target coil.

[0014] The first data is determined based on the frequency of the modulation signal and the current value of the target atomic magnetometer at two zero crossings in response to the static magnetic field.

[0015] Update the frequency of the modulation signal and return to the step of applying the modulation signal of the frequency to the target coil located within the target atomic magnetometer;

[0016] When a preset first condition is met, the coil constant of the target coil is calculated based on each of the first data.

[0017] In one embodiment, calibrating the target coil located within the target atomic magnetometer to obtain the coil constant of the target coil includes:

[0018] Determine the coil current of the target atomic magnetometer, and apply a modulation signal of the coil current to the target coil located within the target atomic magnetometer;

[0019] The frequency of the modulation signal is scanned to determine the frequency values ​​at which the response signal of the target atomic magnetometer in response to the static magnetic field crosses zero twice; the static magnetic field is the magnetic field generated by the current in the target coil.

[0020] The first data is determined based on the coil current and the frequency values ​​of the response signal of the target atomic magnetometer in response to the static magnetic field at two zero crossings;

[0021] Update the coil current and return to the step of applying the modulation signal of the coil current to the target coil located within the target atomic magnetometer;

[0022] When the preset second condition is met, the coil constant of the target coil is calculated based on each of the first data.

[0023] In one embodiment, calculating the coil constant of the target coil based on each of the first data includes:

[0024] The first data are fitted to obtain a first linear relationship between the difference between the fixed parameters and the scanning parameters; the difference between the scanning parameters is determined by the value of the scanning parameters when the response signal of the target atomic magnetometer in response to the static magnetic field crosses zero twice.

[0025] Based on the slope of the first linear relationship, the coil constant of the target coil is calculated;

[0026] Wherein, when the fixed parameter is the frequency of the modulation signal, the scanning parameter is the current of the target coil; and when the fixed parameter is the current of the target coil, the scanning parameter is the frequency of the modulation signal.

[0027] In one embodiment, calibrating the target atomic magnetometer based on the coil constant of the target coil to obtain the response coefficient of the target atomic magnetometer includes:

[0028] Determine the calibration current and apply the calibration current to the target coil to obtain the response signal voltage of the target atomic magnetometer;

[0029] Based on the coil constant of the target coil and the calibration current, calculate the calibration magnetic field corresponding to the calibration current;

[0030] The second data is determined based on the calibrated magnetic field and the response signal voltage;

[0031] Update the calibration current and return to the step of applying the calibration current to the target coil to obtain the response signal voltage of the target atomic magnetometer;

[0032] When the preset third condition is met, the response coefficient of the target atomic magnetometer is calculated based on each of the second data.

[0033] Secondly, this application also provides a calibration device for an atomic magnetometer. The device includes:

[0034] The first calibration module is used to set the environmental parameters of the working environment of the target atomic magnetometer to the environmental parameters of the large magnetic field working environment, and to set the working mode of the target atomic magnetometer to the absolute measurement mode, and to calibrate the target coil located in the target atomic magnetometer to obtain the coil constant of the target coil.

[0035] The second calibration module is used to set the environmental parameters of the target atomic magnetometer to the environmental parameters of a near-zero magnetic operating environment, and to set the operating mode of the target atomic magnetometer to a relative measurement mode. Based on the coil constant of the target coil, the module calibrates the target atomic magnetometer to obtain the response coefficient of the target atomic magnetometer. The response coefficient is used to support the target atomic magnetometer in measuring extremely weak magnetic fields.

[0036] In one embodiment, the first calibration module is specifically used for:

[0037] In response to the magnetometer measurement command, the environmental parameters of the target atomic magnetometer's operating environment are set to those of a large magnetic field operating environment, and the operating mode of the target atomic magnetometer is set to absolute measurement mode; the magnetometer measurement command is used to instruct the target atomic magnetometer to perform magnetic field measurement.

[0038] In one embodiment, the first calibration module is specifically used for:

[0039] Determine the frequency of the modulation signal of the target atomic magnetometer, and apply the modulation signal of the frequency to the target coil located within the target atomic magnetometer;

[0040] The current of the target coil is scanned to determine the current value of the target atomic magnetometer at two zero crossings in response to the static magnetic field; the static magnetic field is the magnetic field generated by the current of the target coil.

[0041] The first data is determined based on the frequency of the modulation signal and the current value of the target atomic magnetometer at two zero crossings in response to the static magnetic field.

[0042] Update the frequency of the modulation signal and return to the step of applying the modulation signal of the frequency to the target coil located within the target atomic magnetometer;

[0043] When a preset first condition is met, the coil constant of the target coil is calculated based on each of the first data.

[0044] In one embodiment, the first calibration module is specifically used for:

[0045] Determine the coil current of the target atomic magnetometer, and apply a modulation signal of the coil current to the target coil located within the target atomic magnetometer;

[0046] The frequency of the modulation signal is scanned to determine the frequency values ​​at which the response signal of the target atomic magnetometer in response to the static magnetic field crosses zero twice; the static magnetic field is the magnetic field generated by the current in the target coil.

[0047] The first data is determined based on the coil current and the frequency values ​​of the response signal of the target atomic magnetometer in response to the static magnetic field at two zero crossings;

[0048] Update the coil current and return to the step of applying the modulation signal of the coil current to the target coil located within the target atomic magnetometer;

[0049] When the preset second condition is met, the coil constant of the target coil is calculated based on each of the first data.

[0050] In one embodiment, the first calibration module is specifically used for:

[0051] The first data are fitted to obtain a first linear relationship between the difference between the fixed parameters and the scanning parameters; the difference between the scanning parameters is determined by the value of the scanning parameters when the response signal of the target atomic magnetometer in response to the static magnetic field crosses zero twice.

[0052] Based on the slope of the first linear relationship, the coil constant of the target coil is calculated;

[0053] Wherein, when the fixed parameter is the frequency of the modulation signal, the scanning parameter is the current of the target coil; and when the fixed parameter is the current of the target coil, the scanning parameter is the frequency of the modulation signal.

[0054] In one embodiment, the second calibration module is specifically used for:

[0055] Determine the calibration current and apply the calibration current to the target coil to obtain the response signal voltage of the target atomic magnetometer;

[0056] Based on the coil constant of the target coil and the calibration current, calculate the calibration magnetic field corresponding to the calibration current;

[0057] The second data is determined based on the calibrated magnetic field and the response signal voltage;

[0058] Update the calibration current and return to the step of applying the calibration current to the target coil to obtain the response signal voltage of the target atomic magnetometer;

[0059] When the preset third condition is met, the response coefficient of the target atomic magnetometer is calculated based on each of the second data.

[0060] Thirdly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps described in the first aspect.

[0061] Fourthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, performs the steps described in the first aspect.

[0062] Fifthly, this application also provides a computer program product. The computer program product includes a computer program that, when executed by a processor, implements the steps described in the first aspect.

[0063] The aforementioned calibration method, apparatus, computer equipment, storage medium, and computer program product for atomic magnetometers set the environmental parameters of the target atomic magnetometer's operating environment to those of a large magnetic field operating environment and set the target atomic magnetometer's operating mode to an absolute measurement mode. The target coil located within the target atomic magnetometer is calibrated to obtain its coil constant. Alternatively, the environmental parameters of the target atomic magnetometer's operating environment are set to those of a near-zero magnetic field operating environment and the target atomic magnetometer's operating mode is set to a relative measurement mode. Based on the coil constant of the target coil, the target atomic magnetometer is calibrated to obtain its response coefficient. This response coefficient is used to support the target atomic magnetometer in measuring extremely weak magnetic fields. In this way, in absolute measurement mode, the coil constant of the target coil located inside the target atomic magnetometer is calibrated. Then, based on the calibrated coil constant, in relative measurement mode, the response coefficient of the target atomic magnetometer is calibrated. The calibrated sensor and the calibrated sensor are the same sensor. The atomic magnetometer calibrates itself. The position and sensitive axis pointing of the same atomic magnetometer in the two measurement modes are strictly consistent. There are no position errors or orientation errors, and no in-situ calibration errors, thereby reducing the calibration error of the atomic magnetometer. Attached Figure Description

[0064] Figure 1 This is a flowchart illustrating the calibration method of an atomic magnetometer in one embodiment;

[0065] Figure 2 This is a schematic diagram of a typical single-beam atomic magnetometer in one embodiment;

[0066] Figure 3 This is a schematic diagram illustrating the working principle of an atomic magnetometer in one embodiment;

[0067] Figure 4 This is a schematic diagram of the waveform of the output voltage of an atomic magnetometer when scanning a magnetic field in one embodiment;

[0068] Figure 5 This is a schematic diagram of the waveform of the atomic magnetometer output voltage when scanning the modulation frequency in one embodiment;

[0069] Figure 6 This is a flowchart illustrating the calibration steps for a target coil located within a target atomic magnetometer in one embodiment.

[0070] Figure 7 This is a flowchart illustrating the calibration steps for a target coil located within a target atomic magnetometer, as described in another embodiment.

[0071] Figure 8This is a flowchart illustrating the steps for calculating the coil constant of the target coil in one embodiment;

[0072] Figure 9 This is a flowchart illustrating the calibration steps for a target atomic magnetometer in one embodiment;

[0073] Figure 10 This is a structural block diagram of a calibration device for an atomic magnetometer in one embodiment;

[0074] Figure 11 This is an internal structural diagram of a computer device in one embodiment; wherein, 1, light source; 2, light beam emitted by the light source; 3, quarter-wave plate; 4, atomic gas chamber; 5, triaxial coil; 6, photodetector; 7, heater; 8, atomic magnetometer probe. Detailed Implementation

[0075] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0076] In one embodiment, such as Figure 1 As shown, a calibration method for an atomic magnetometer is provided. This embodiment illustrates the application of this method to a terminal. It is understood that this method can also be applied to a server, and to a system including both a terminal and a server, and is implemented through interaction between the terminal and the server. The terminal can be, but is not limited to, various personal computers, laptops, smartphones, tablets, IoT devices, and portable wearable devices. IoT devices can include smart speakers, smart TVs, smart air conditioners, smart in-vehicle devices, etc. Portable wearable devices can include smartwatches, smart bracelets, head-mounted devices, etc. The server can be a standalone server or a server cluster consisting of multiple servers. In this embodiment, the method includes the following steps:

[0077] Step 101: Set the environmental parameters of the target atomic magnetometer to the parameters of a large magnetic field working environment, set the working mode of the target atomic magnetometer to absolute measurement mode, calibrate the target coil located inside the target atomic magnetometer, and obtain the coil constant of the target coil.

[0078] In this embodiment, the terminal sets the environmental parameters of the target atomic magnetometer's operating environment to those of a large magnetic field operating environment. Then, the terminal sets the target atomic magnetometer's operating mode to absolute measurement mode. Next, the terminal calibrates the target coil located within the target atomic magnetometer to obtain the coil constant. Here, the target atomic magnetometer is the atomic magnetometer to be calibrated. The target atomic magnetometer can be the atomic magnetometer to be used. The atomic magnetometer can be a spin-exchange relaxation-free (SERF) atomic magnetometer. A coil exists inside the atomic magnetometer, and this coil can be a triaxial coil. The target coil is the coil located inside the target atomic magnetometer. The coil constant can be the response coefficient between the current applied to the coil and the corresponding magnetic field generated by the coil. The coil constant is related to the coil's geometry and the number of turns. A large magnetic field operating environment is an operating environment where the magnetic field is greater than a preset first magnetic field threshold.

[0079] In one embodiment, a typical single-beam atomic magnetometer structure is as follows: Figure 2 The atomic magnetometer includes: an atomic magnetometer probe, a gas chamber temperature control module, a light source control module, a signal detection module, a signal processing module, a coil control module, and a Direct Digital Synthesis (DDS) signal generation module. The atomic magnetometer probe (8) consists of a light source (1), a quarter-wave plate (3), an atomic gas chamber (4), a triaxial coil (5), a photodetector (6), and a heater (7). The light source control module controls the light source inside the probe to operate at a specific wavelength, power, and polarization state. The light beam (2) emitted by the light source is changed from linearly polarized light to circularly polarized light after passing through the quarter-wave plate (3). Then, after interacting with atoms through the atomic gas chamber, it acts as pump light to cause atoms to be housed at a specific energy level, forming macroscopic polarization. On the other hand, it acts as probe light, and the change in its absorption intensity reflects the magnitude of the magnetic field change. The optical signal is detected and received by the photodetector (6), and after being processed by the signal detection and processing module, it is output by the atomic magnetometer. In some atomic magnetometer probe designs, a dual-beam configuration may be used, with one beam serving as the pump beam and the other as the probe beam; alternatively, a multi-source and multi-beam approach may be employed. It is understood that atomic magnetometers with different source and beam configurations can all be calibrated using the method described in this application.

[0080] The working principle of an atomic magnetometer is as follows: Figure 3 As shown. The pump light is along the x-axis, the external magnetic field to be measured B0 is along the z-axis, and a modulation signal B is applied in the direction of the magnetic field to be measured. m cosω m Under the influence of the magnetic field of the modulation signal, the spin evolution equation of an atom can be described by the following Bloch equation:

[0081]

[0082] in, This represents the spin polarization of an atom, where t is time. These represent magnetic field amplitudes B0 and B, respectively. m Larmor precession frequency, q is the nuclear deceleration factor, γ is the gyromagnetic ratio of a single electron, R op and R rel These represent the optical pump rate and relaxation rate, respectively. Let ω be the optical pumping vector along the direction of the pump light's travel. m Let B be the frequency of the modulating signal. Solve the above Bloch equation and take the first-order component of the solution (i.e., containing the modulating signal B) as the solution. m cosω m t First-order modulation frequency ω m Using the solution as an approximation, the atomic polarization vector along the x-axis can be obtained as:

[0083]

[0084] Where P0 represents the effective polarization of an atom. Denotes the coefficients of the 0th order Bessel series. Let represent the coefficients of the first-order Bessel series. According to P... x From the form of the solution, we can deduce that when ω0=nω m When n = 0, ±1, ±2, etc., magnetic field resonance will occur. If the magnetic field B0 is scanned under a certain modulation frequency (e.g., scanning the magnitude of the magnetic field coil current), the photodetector output can obtain the following: Figure 4 The signal shown. If, under the influence of a certain magnetic field, the modulation frequency of the scanning coil makes ω m When changes occur, the output of the photodetector can obtain, for example... Figure 5 The signal shown.

[0085] The atomic magnetometer operates in two modes: absolute measurement mode and relative measurement mode. The absolute measurement mode is a non-SERF absolute measurement mode. Under certain B0 conditions, the modulation frequency ω of the scanning magnetic field is... m Alternatively, by scanning the coil current to scan the magnetic field B0 at a certain modulation frequency, one can obtain, for example... Figure 5 The spectral lines shown. The frequency difference between the zero-crossing points of two adjacent spectral lines. Under the same conditions, Since the magnetic field is constant, it is measured through frequency measurement, which is an absolute measurement. This operating mode is suitable for scenarios with relatively large magnetic fields. When the magnetic field is relatively small, several zero-crossing points will overlap, causing measurement errors. The relative measurement mode is the SERF relative measurement mode. In a near-zero magnetic environment, the demodulated signal of the photodetector changes with the magnetic field as follows: Figure 5 The example shown is for the case where n=0. When the atomic magnetometer operates in SERF mode, the signal linewidth narrows, thus significantly increasing measurement sensitivity. In this linear region of SERF operation, the output signal voltage changes with the magnetic field, making it a relative measurement. Therefore, the magnetic field response coefficients of the input magnetic field and output voltage need to be calibrated, i.e., the response coefficients of the atomic magnetometer. This measurement mode is suitable for near-zero magnetic field conditions and offers high sensitivity.

[0086] Step 102: Set the environmental parameters of the target atomic magnetometer to the parameters of a near-zero magnetic working environment, and set the working mode of the target atomic magnetometer to a relative measurement mode. Based on the coil constant of the target coil, calibrate the target atomic magnetometer to obtain the response coefficient of the target atomic magnetometer.

[0087] The response coefficient is used to support the target atomic magnetometer in measuring extremely weak magnetic fields.

[0088] In this embodiment, the terminal sets the environmental parameters of the target atomic magnetometer's operating environment to those of a near-zero magnetic operating environment. Then, the terminal sets the target atomic magnetometer's operating mode to a relative measurement mode. Next, the terminal calibrates the target atomic magnetometer based on the coil constant of the target coil to obtain the target atomic magnetometer's response coefficient. The near-zero magnetic operating environment is defined as an environment where the magnetic field is less than a preset second magnetic field threshold. The second magnetic field threshold is less than a first magnetic field threshold.

[0089] In the above calibration method for an atomic magnetometer, the environmental parameters of the target atomic magnetometer's operating environment are set to those of a large magnetic field operating environment, and the operating mode of the target atomic magnetometer is set to absolute measurement mode. The target coil located within the target atomic magnetometer is calibrated to obtain the coil constant of the target coil. The environmental parameters of the target atomic magnetometer's operating environment are then set to those of a near-zero magnetic field operating environment, and the operating mode of the target atomic magnetometer is set to relative measurement mode. Based on the coil constant of the target coil, the target atomic magnetometer is calibrated to obtain its response coefficient. This response coefficient is used to support the target atomic magnetometer in measuring extremely weak magnetic fields. In this way, in absolute measurement mode, the coil constant of the target coil located inside the target atomic magnetometer is calibrated. Then, based on the calibrated coil constant, the response coefficient of the target atomic magnetometer is calibrated in relative measurement mode. The calibrated sensor and the calibrated sensor are the same sensor; the atomic magnetometer calibrates itself. The position and sensitive axis orientation of the same atomic magnetometer are strictly consistent in both measurement modes, eliminating positional and directional errors and in-situ calibration errors. This reduces the calibration error of the atomic magnetometer, improves its calibration accuracy, and consequently improves its measurement accuracy. This is of great significance for the accurate measurement of weak magnetic field signals such as magnetocardiography (MCG) and magnetocardiography (MCG). Moreover, this method eliminates the performance difference between the used and calibrated sensors, further reducing the calibration error of the atomic magnetometer and improving its calibration accuracy.

[0090] In one embodiment, the specific process of setting the environmental parameters of the target atomic magnetometer's operating environment to the environmental parameters of a large magnetic field operating environment and setting the operating mode of the target atomic magnetometer to an absolute measurement mode includes the following steps: in response to the magnetometer measurement command, setting the environmental parameters of the target atomic magnetometer's operating environment to the environmental parameters of a large magnetic field operating environment and setting the operating mode of the target atomic magnetometer to an absolute measurement mode.

[0091] Among them, the magnetometer measurement command is used to instruct the target atomic magnetometer to measure the magnetic field.

[0092] In this embodiment, before each magnetic field measurement by the target atomic magnetometer, the target atomic magnetometer sends a magnetometer measurement command to the terminal. The terminal receives the magnetometer measurement command. Then, in response to the magnetometer measurement command, the terminal sets the environmental parameters of the target atomic magnetometer's operating environment to the environmental parameters of a large magnetic field operating environment, and sets the target atomic magnetometer's operating mode to absolute measurement mode. The magnetometer measurement command can be used to instruct the target atomic magnetometer to measure the magnetic field in various operating environments. Alternatively, the magnetometer measurement command can be used only to instruct the target atomic magnetometer to measure the magnetic field in a near-zero magnetic field operating environment.

[0093] In the aforementioned calibration method for atomic magnetometers, in response to the magnetometer measurement command, the environmental parameters of the target atomic magnetometer's operating environment are set to those of a large magnetic field operating environment, and the operating mode of the target atomic magnetometer is set to absolute measurement mode. During the use of the SERF atomic magnetometer, due to differences between the operating environment and the calibration environment, there are performance differences between the used and calibrated sensors, such as variations in the SERF linewidth caused by the environmental magnetic field gradient. Furthermore, variations in the SERF atomic magnetometer's temperature and the performance of its components (such as laser power and polarization) lead to changes in the SERF atomic magnetometer's scaling factor during actual use. Especially in applications involving magnetocardiography (MCG) and magnetoencephalography (MEG), for different test cases, variations in probe position, surrounding residual magnetic field, and magnetic field gradient noise can cause significant differences between the actual measured magnetic response coefficient and the calibrated response coefficient, resulting in errors and distortions in the MEG. Unlike traditional atomic magnetometer calibration methods that rely on a single calibration with a standard coil, this method recalibrates the atomic magnetometer before each magnetic field measurement. This means the atomic magnetometer is calibrated during operation, i.e., online calibration. The operating environment is identical to the calibration environment, eliminating differences in sensor performance and the temperature and component performance variations inherent in SERF atomic magnetometers. This solves the problem of environmental response coefficient drift inherent in traditional calibration methods, further reducing calibration errors and improving calibration accuracy. Consequently, it enhances the accuracy of extremely weak magnetic field detection and the precision and fidelity of SERF-based magnetocardiography.

[0094] To obtain a measurement of the coil constant C, the target atomic magnetometer is operated in absolute measurement mode, by measuring, for example... Figure 4-5 The frequency difference between the different zero-crossing signals shown is used to measure the coil constant C. There are two specific measurement schemes:

[0095] Option 1: Fix the frequency ω of the modulation signal mThe scanning coil current I changes the magnetic field B. For example... Figure 4 The signal from the photodetector shown exhibits a dispersive linear pattern. Let the magnetic field strengths corresponding to two zero crossings be B, respectively. i and B j (i = -1, 0, +1), the corresponding currents are I respectively. i and I j Assuming the residual magnetism caused by the environment corresponding to the two zero crossings is the same, we have:

[0096] B i =CI i +B a

[0097] B j =CI j +B a

[0098] Subtracting the above equations, we get:

[0099] ΔB=CΔI

[0100] in, ΔI=I i -I j A single measurement yields (ΔB) 1 ΔI 1 ). Change the frequency ω of the modulation signal m Repeat the above process to obtain the second group (ΔB). 2 ΔI 2 Repeat the above process n times, and obtain the corresponding coefficients C by performing linear fitting based on n sets of data.

[0101] Option 2: Fix the magnitude of the coil current I, and scan the frequency ω of the modulation signal. m ,like Figure 5 As shown, similarly, demodulating the photodetector signal using a demodulated signal of the same frequency will yield the corresponding dispersive signal. In this process, assume that the modulation frequencies corresponding to the two zero-crossing resonances are respectively... and (i, j = -1, 0, +1), then the magnetic field strength under the action of coil current I is: The recorded data is (B) 1 I 1 By changing the magnitude I of the coil current and repeating the above process, we obtain (B). 2 I 2 Repeat the above process n times, and obtain the coil constant C and remanence Ba by linear fitting based on n sets of data.

[0102] In one embodiment, such as Figure 6As shown, the specific process of calibrating the target coil located inside the target atomic magnetometer to obtain the coil constant of the target coil includes the following steps:

[0103] Step 601: Determine the frequency of the modulation signal of the target atomic magnetometer, and apply the modulation signal of that frequency to the target coil located inside the target atomic magnetometer.

[0104] In this embodiment, the terminal determines the frequency of the modulation signal of the target atomic magnetometer. Then, the terminal applies the modulation signal of that frequency to the target coil located within the target atomic magnetometer.

[0105] In one example, the terminal uses the direction of the pump light as the x-axis. Then, the terminal applies a modulated magnetic field of that frequency along the z-axis through the target coil located within the target atomic magnetometer.

[0106] Step 602: Scan the current of the target coil to determine the current value of the target atomic magnetometer when the response signal to the static magnetic field crosses zero twice.

[0107] Among them, the static magnetic field is the magnetic field generated by the current in the target coil.

[0108] In this embodiment, the terminal scans the current of the target coil to obtain the current value of the target atomic magnetometer's response signal to the static magnetic field. Then, the terminal determines the current value of the target atomic magnetometer's response signal to the static magnetic field at the two zero crossings from the current value of the response signal.

[0109] In one embodiment, the terminal scans the magnetic field of the target coil to determine the current value of the target atomic magnetometer at two zero crossings in response to the static magnetic field. The specific process is similar to that of scanning the current of the target coil.

[0110] Step 603: Determine the first data based on the frequency of the modulation signal and the current value when the target atomic magnetometer responds to the static magnetic field at two zero crossings.

[0111] In this embodiment, the terminal calculates the difference between the current values ​​of the target atomic magnetometer's response signal to the static magnetic field at the two zero-crossings. Then, the terminal calculates the difference in the number of zero-crossings of the target atomic magnetometer's response signal to the static magnetic field at the two zero-crossings. The terminal then divides the current difference by the difference in the number of zero-crossings to obtain the target value. Finally, the terminal combines the frequency of the modulation signal and the target value to form first data. The first data is a data pair, which includes the frequency of the modulation signal and the target value.

[0112] In one example, the first data is a coordinate value. The terminal calculates the absolute value of the target value. Then, the terminal uses the frequency of the modulated signal as the horizontal axis and the absolute value of the target value as the vertical axis to obtain the first data. For example, the first data is a data point (ω). m ,|I1-I2|),ω m I1 and I2 are the current values ​​of the target atomic magnetometer at two consecutive zero crossings in response to the static magnetic field.

[0113] Step 604: Update the frequency of the modulation signal and return to the step of applying the modulation signal with the frequency to the target coil located inside the target atomic magnetometer.

[0114] In this embodiment, the terminal updates the frequency of the modulation signal. Then, the terminal returns to the step of applying the modulation signal with the frequency to the target coil located within the target atomic magnetometer.

[0115] Step 605: When the preset first condition is met, calculate the coil constant of the target coil based on each first data.

[0116] In this embodiment, when a preset first condition is met, the terminal calculates the coil constant of the target coil using the least squares method based on each set of first data. Specifically, the terminal determines whether the number of first data points reaches a preset first quantity threshold. If the number of first data points reaches the preset first quantity threshold, the terminal determines that the preset first condition is met.

[0117] In the above-mentioned calibration method for an atomic magnetometer, the frequency of the modulation signal of the target atomic magnetometer is fixed, and the modulation signal of that frequency is applied to the target coil located inside the target atomic magnetometer; the current of the target coil is scanned to determine the current value when the response signal of the target atomic magnetometer in response to the static magnetic field crosses zero twice; then, based on the frequency of the modulation signal and the current value when the response signal of the target atomic magnetometer in response to the static magnetic field crosses zero twice, the first data is determined; the frequency of the modulation signal is changed, and the step of applying the modulation signal of the frequency to the target coil located inside the target atomic magnetometer is returned; when the number of first data is sufficient, the coil constant of the target coil is calculated based on each first data. In this way, by fixing the frequency of the modulation signal and scanning the current of the target coil, a series of first data points are obtained. Then, by fitting these first data points, the coil constant of the target coil is calculated. Compared to the traditional method using a standard coil, this method utilizes the response characteristics of the atomic magnetometer itself to calculate the coil constant of the target coil within the atomic magnetometer. This ensures that the position and sensitive axis orientation of the same atomic magnetometer are strictly consistent in both measurement modes, eliminating in-situ calibration errors and thus reducing the calibration error of the atomic magnetometer, improving its calibration accuracy, and consequently, its measurement accuracy. Furthermore, this method, by utilizing the response characteristics of the atomic magnetometer itself to calculate the coil constant of the target coil within the atomic magnetometer, also avoids coil constant errors caused by time-varying coil values, further reducing the calibration error of the atomic magnetometer.

[0118] In one embodiment, such as Figure 7 As shown, the specific process of calibrating the target coil located inside the target atomic magnetometer to obtain the coil constant of the target coil includes the following steps:

[0119] Step 701: Determine the coil current of the target atomic magnetometer and apply a modulation signal of the coil current to the target coil located inside the target atomic magnetometer.

[0120] In this embodiment, the terminal determines the coil current of the target atomic magnetometer. Then, the terminal applies a modulation signal of the coil current to the target coil located within the target atomic magnetometer.

[0121] In one example, the terminal uses the direction of the pump light as the x-axis direction. Then, the terminal applies a modulated magnetic field along the z-axis to the target coil current through the target coil located within the target atomic magnetometer.

[0122] Step 702: Scan the frequency of the modulation signal to determine the frequency values ​​of the response signal of the target atomic magnetometer to the static magnetic field when it crosses zero twice.

[0123] Among them, the static magnetic field is the magnetic field generated by the current in the target coil.

[0124] In this embodiment, the terminal scans the frequency of the modulation signal to obtain the frequency value of the response signal of the target atomic magnetometer in response to the static magnetic field. Then, the terminal determines the frequency value of the response signal of the target atomic magnetometer in response to the static magnetic field when it crosses zero twice from the frequency value of the response signal of the target atomic magnetometer in response to the static magnetic field.

[0125] Step 703: Determine the first data based on the coil current and the frequency values ​​of the response signal of the target atomic magnetometer to the static magnetic field at the two zero crossings.

[0126] In this embodiment, the terminal calculates the difference between the frequency values ​​of the target atomic magnetometer's response signal to the static magnetic field at the two zero-crossings. Then, the terminal calculates the difference in the number of zero-crossings of the target atomic magnetometer's response signal to the static magnetic field at the two zero-crossings. The terminal then divides the frequency difference by the difference in the number of zero-crossings to obtain the target value. Finally, the terminal combines the coil current and the target value to form first data. The first data is a data pair, which includes the coil current and the target value.

[0127] In one example, the first data is a coordinate value. The terminal calculates the absolute value of the target value. Then, the terminal uses the coil current as the x-axis and the absolute value of the target value as the y-axis to obtain the first data. For example, the first data is the data point (I, |ω...). m1 -ω m2 |), I is the coil current, ω m1 ω m2 These are the frequency values ​​of the target atomic magnetometer's response signal to the static magnetic field at two consecutive zero crossings.

[0128] Step 704: Update the coil current and return to the step of applying the modulation signal of the coil current to the target coil located within the target atomic magnetometer.

[0129] In this embodiment, the terminal updates the coil current. Then, the terminal returns to the step of applying a modulation signal to the target coil located within the target atomic magnetometer to apply the coil current.

[0130] Step 705: When the preset second condition is met, calculate the coil constant of the target coil based on each first data.

[0131] In this embodiment, when a preset second condition is met, the terminal calculates the coil constant of the target coil using the least squares method based on each set of first data. Specifically, the terminal determines whether the number of first data points reaches a preset second threshold. If the number of first data points reaches the preset second threshold, the terminal determines that the preset second condition is met. The first threshold may be the same as or different from the second threshold.

[0132] In the above-mentioned calibration method for an atomic magnetometer, the coil current of the target atomic magnetometer is fixed, and a modulation signal of the coil current is applied to the target coil located inside the target atomic magnetometer; the frequency of the modulation signal is scanned to determine the frequency value at which the response signal of the target atomic magnetometer in response to the static magnetic field crosses zero twice; then, based on the coil current and the frequency value at which the response signal of the target atomic magnetometer in response to the static magnetic field crosses zero twice, first data is determined; the coil current is changed, and the step of applying the modulation signal of the coil current to the target coil located inside the target atomic magnetometer is returned; when the number of first data is sufficient, the coil constant of the target coil is calculated based on each first data. In this way, by fixing the coil current and scanning the frequency of the modulation signal, a series of first data points are obtained. Then, by fitting these first data points, the coil constant of the target coil is calculated. This is another method for calibrating the target coil located inside the atomic magnetometer. Compared to the traditional method using a standard coil, this method utilizes the atomic magnetometer's own response characteristics to calculate the coil constant of the target coil inside the atomic magnetometer. This ensures that the position and sensitive axis orientation of the same atomic magnetometer are strictly consistent in both measurement modes, eliminating in-situ calibration errors. This reduces the calibration error of the atomic magnetometer, improves its calibration accuracy, and ultimately enhances its measurement accuracy. Furthermore, this method, by utilizing the atomic magnetometer's own response characteristics to calculate the coil constant of the target coil inside the atomic magnetometer, also avoids coil constant errors caused by time-varying coil values, further reducing the calibration error of the atomic magnetometer.

[0133] In one embodiment, such as Figure 8 As shown, the specific process of calculating the coil constant of the target coil based on the first data includes the following steps:

[0134] Step 801: Fit each of the first data points to obtain the first linear relationship between the difference between the fixed parameters and the scanning parameters.

[0135] The difference in scanning parameters is determined by the values ​​of the scanning parameters when the target atomic magnetometer responds to the static magnetic field signal and the signal crosses zero twice.

[0136] In this embodiment, the terminal fits each set of first data using a fitting method to obtain a first linear relationship between the difference between fixed parameters and scanning parameters. The fixed parameters are those fixed during scanning. These fixed parameters can be the frequency of the modulation signal of the target atomic magnetometer, the coil current of the target atomic magnetometer, and the static magnetic field of the target atomic magnetometer. The static magnetic field of the target atomic magnetometer is the magnetic field generated by applying the coil current to the target coil of the target atomic magnetometer. The scanning parameters are the parameters being scanned during scanning. These scanning parameters can be the frequency of the modulation signal of the target atomic magnetometer, the coil current of the target atomic magnetometer, and the static magnetic field of the target atomic magnetometer. The fixed parameters are different from the scanning parameters. The fitting method is the method used to fit the data. For example, the fitting method can be the least squares method. The difference between the scanning parameters can be a target value or the absolute value of the target value.

[0137] Step 802: Calculate the coil constant of the target coil based on the slope of the first linear relationship.

[0138] In this case, with the frequency of the modulation signal as a fixed parameter, the scanning parameter is the current of the target coil.

[0139] In this embodiment, the terminal calculates the coil constant of the target coil based on the slope of the first linear relationship, the nuclear deceleration factor, and the gyromagnetic ratio of a single electron. In absolute measurement mode, due to the high magnetic field environment, the atomic magnetometer operates in a non-SERF state, and the nuclear deceleration factor is positively correlated with the nuclear spin quantum number of the atom. In relative measurement mode, due to the near-zero magnetic environment, the atomic magnetometer operates in a SERF state, and the nuclear deceleration factor varies depending on the polarization intensity. The calibration method of the atomic magnetometer in this application is in-situ calibration, which does not require consideration of these factors; that is, the method for determining the nuclear deceleration factor in relative measurement mode is the same as the method for determining the nuclear deceleration factor in absolute measurement mode.

[0140] In one example, with the frequency of the modulation signal as a fixed parameter, the current of the target coil is scanned as the parameter. The terminal calculates the product of the slope of the first linear relationship and the gyromagnetic ratio of a single electron. Then, the terminal divides this product by the nuclear deceleration factor of the target atomic magnetometer to obtain the coil constant of the target coil.

[0141] In one example, with the target coil's current as a fixed parameter, the scanning parameter is the frequency of the modulation signal. The terminal calculates the product of the slope of the first linear relationship and the nuclear deceleration factor of the target atomic magnetometer. Then, the terminal divides this product by the gyromagnetic ratio of a single electron to obtain the coil constant of the target coil.

[0142] In one example, the terminal determines the nuclear spin quantum number of the atoms in the target atomic magnetometer based on the atom type. Then, the terminal calculates the nuclear deceleration factor of the target atomic magnetometer based on the nuclear spin quantum number of the atoms.

[0143] In one embodiment, the nuclear deceleration factor of the target atomic magnetometer can be calculated by the terminal as: q = 2I + 1, where q is the nuclear deceleration factor of the target atomic magnetometer, and I is the nuclear spin quantum number of the atom in the target atomic magnetometer. For example, when the atom type of the target atomic magnetometer is rubidium, the nuclear spin quantum number of the atom in the target atomic magnetometer is...

[0144] In the above-described calibration method for an atomic magnetometer, the first data points are fitted to obtain a first linear relationship between the difference between the fixed parameters and the scanning parameters. Based on the slope of this first linear relationship, the coil constant of the target coil is calculated. Thus, by fitting the first data points to obtain the slope of the first linear relationship and the response characteristics of the atomic magnetometer itself, the coil constant of the target coil is calculated. Compared to the traditional method using a standard coil, this method ensures that the position and sensitive axis orientation of the same atomic magnetometer are strictly consistent in both measurement modes, eliminating in-situ calibration errors. This reduces the calibration error of the atomic magnetometer, improves its calibration accuracy, and consequently enhances its measurement accuracy. Furthermore, this method avoids coil constant errors caused by time-varying coils, further reducing the calibration error of the atomic magnetometer.

[0145] In one embodiment, the specific process of setting the environmental parameters of the target atomic magnetometer to near-zero magnetic operating environment parameters is as follows: stop scanning and adjust the frequency of the modulation signal to a frequency outside the operating bandwidth. With the modulation signal frequency as the fixed parameter and the target coil current as the scanning parameter, the terminal stops scanning and no longer scans the target coil current. Similarly, with the target coil current as the fixed parameter and the modulation signal frequency as the scanning parameter, the terminal stops scanning and no longer scans the modulation signal frequency.

[0146] In one embodiment, such as Figure 9 As shown, the specific process of calibrating the target atomic magnetometer based on the coil constant of the target coil and obtaining the response coefficient of the target atomic magnetometer includes the following steps:

[0147] Step 901: Determine the calibration current and apply the calibration current to the target coil to obtain the response signal voltage of the target atomic magnetometer.

[0148] In this embodiment, the terminal determines the calibration current. Then, the terminal applies the calibration current to the target coil to obtain the response signal voltage of the target atomic magnetometer. Here, the calibration current is the current used to calibrate the response coefficient of the target atomic magnetometer. The response signal voltage is the voltage generated by the calibration current in the target atomic magnetometer, and is the output voltage of the target atomic magnetometer.

[0149] Step 902: Calculate the calibration magnetic field corresponding to the calibration current based on the coil constant and calibration current of the target coil.

[0150] In this embodiment, the terminal calculates the calibration magnetic field corresponding to the calibration current based on the coil constant and calibration current of the target coil. The calibration magnetic field is used to calibrate the response coefficient of the target atomic magnetometer. The calibration magnetic field is the magnetic field generated by the target atomic magnetometer when the calibration current is applied. The coil generates the calibration magnetic field by applying the calibration current to the sensitive area of ​​the magnetometer, i.e., the area where the atomic gas cell and light interact. The calibration magnetic field is approximately proportional to the calibration current and can be expressed as: B = CI + B a Where B is the calibration magnetic field, I is the calibration current, and C is the coil constant. a This refers to the residual magnetic field in the environment, which is the magnetic field in the environment when no current is applied (considered to be constant under the same operating conditions).

[0151] In one example, the target atomic magnetometer operates in a near-zero magnetic environment, assuming the residual environmental remanence is 0. The terminal calculates the product of the calibration current and the coil constant, and uses this product as the calibration magnetic field corresponding to the calibration current.

[0152] Step 903: Determine the second data based on the calibrated magnetic field and the response signal voltage.

[0153] In this embodiment, the terminal uses the calibration magnetic field and the response signal voltage to form second data. The second data is a data pair, which includes the calibration magnetic field and the response signal voltage.

[0154] In one example, the second data is a coordinate value. The terminal uses the calibration magnetic field as the x-axis and the response signal voltage as the y-axis to obtain the second data. For example, the second data is the data point (B0, V0), where B0 is the calibration magnetic field and V0 is the response signal voltage.

[0155] Step 904: Update the calibration current and return to the step of applying the calibration current to the target coil to obtain the response signal voltage of the target atomic magnetometer.

[0156] In this embodiment, the terminal updates the calibration current. Then, the terminal returns to the step of applying the calibration current to the target coil to obtain the response signal voltage of the target atomic magnetometer.

[0157] Step 905: When the preset third condition is met, calculate the response coefficient of the target atomic magnetometer based on each second data.

[0158] In this embodiment of the application, when the preset third condition is met, the terminal calculates the response coefficient of the target atomic magnetometer using the least squares method based on each second data.

[0159] In one example, the terminal determines whether the quantity of the second data reaches a preset third quantity threshold. If the quantity of the second data reaches the preset third quantity threshold, the terminal determines that the preset third condition is met.

[0160] Detecting P using a photodetector x After signal processing such as modulation and demodulation, the output voltage V(B) can be obtained. z ) and the z-axis magnetic field to be measured (i.e., the calibration magnetic field) B z The relationship is as follows:

[0161]

[0162] Where A0 is a simplified scaling factor, i.e., the response coefficient of the target atomic magnetometer. Since B... z Since it is close to 0, the above formula can be approximately written as V(B) z )=A0B z .

[0163] In one example, the terminal uses a fitting method to fit each of the second data points to obtain a second linear relationship between the calibrated magnetic field and the response signal voltage. Then, the terminal uses the slope of this second linear relationship as the response coefficient of the target atomic magnetometer. The fitting method used to fit each of the second data points can be the same as or different from the fitting method used to fit each of the first data points.

[0164] In the above-described calibration method for an atomic magnetometer, a fixed calibration current is applied to the target coil to obtain the response signal voltage of the target atomic magnetometer; based on the coil constant of the target coil and the calibration current, the calibration magnetic field corresponding to the calibration current is calculated; second data is determined based on the calibration magnetic field and the response signal voltage; the calibration current is changed, and the process of applying the calibration current to the target coil to obtain the response signal voltage of the target atomic magnetometer is repeated; when a preset third condition is met, the response coefficient of the target atomic magnetometer is calculated based on each set of second data. In this way, by fixing the calibration current, obtaining its corresponding response signal voltage, and obtaining the calibration magnetic field corresponding to the determined calibration current based on the determined coil constant, and then using a fitting method to calculate the response coefficient of the target atomic magnetometer based on the obtained sets of second data composed of the calibration magnetic field and the response signal voltage, errors caused by single data points can be avoided, further reducing the calibration error of the atomic magnetometer, further improving the calibration accuracy of the atomic magnetometer, and thus further improving the measurement accuracy of the atomic magnetometer.

[0165] The above process only applies to results obtained when both the static magnetic field and the modulation magnetic field are oriented along the z-axis. Similarly, if the static magnetic field and the modulation magnetic field are oriented along the y-axis, the magnetic field response coefficient along the y-axis can be calibrated, and the specific process for calibrating the magnetic field response coefficient along the y-axis is similar to the process described above. Therefore, the calibration method for the atomic magnetometer of this application is applicable to the calibration of multi-axis atomic magnetometers.

[0166] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0167] Based on the same inventive concept, this application also provides a calibration device for an atomic magnetometer to implement the calibration method of the atomic magnetometer described above. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more embodiments of the atomic magnetometer calibration device provided below can be found in the limitations of the atomic magnetometer calibration method described above, and will not be repeated here.

[0168] In one embodiment, such as Figure 10As shown, a calibration device 1000 for an atomic magnetometer is provided, comprising: a first calibration module 1010 and a second calibration module 1020, wherein:

[0169] The first calibration module 1010 is used to set the environmental parameters of the working environment of the target atomic magnetometer to the environmental parameters of the large magnetic field working environment, set the working mode of the target atomic magnetometer to the absolute measurement mode, calibrate the target coil located in the target atomic magnetometer, and obtain the coil constant of the target coil.

[0170] The second calibration module 1020 is used to set the environmental parameters of the target atomic magnetometer to the environmental parameters of the near-zero magnetic working environment, and to set the working mode of the target atomic magnetometer to the relative measurement mode. Based on the coil constant of the target coil, the target atomic magnetometer is calibrated to obtain the response coefficient of the target atomic magnetometer. The response coefficient is used to support the target atomic magnetometer in measuring extremely weak magnetic fields.

[0171] Optionally, the first calibration module 1010 is specifically used for:

[0172] In response to the magnetometer measurement command, the environmental parameters of the target atomic magnetometer's operating environment are set to those of a large magnetic field operating environment, and the operating mode of the target atomic magnetometer is set to absolute measurement mode; the magnetometer measurement command is used to instruct the target atomic magnetometer to perform magnetic field measurement.

[0173] Optionally, the first calibration module 1010 is specifically used for:

[0174] Determine the frequency of the modulation signal of the target atomic magnetometer, and apply the modulation signal of the frequency to the target coil located within the target atomic magnetometer;

[0175] The current of the target coil is scanned to determine the current value of the target atomic magnetometer at two zero crossings in response to the static magnetic field; the static magnetic field is the magnetic field generated by the current of the target coil.

[0176] The first data is determined based on the frequency of the modulation signal and the current value of the target atomic magnetometer at two zero crossings in response to the static magnetic field.

[0177] Update the frequency of the modulation signal and return to the step of applying the modulation signal of the frequency to the target coil located within the target atomic magnetometer;

[0178] When a preset first condition is met, the coil constant of the target coil is calculated based on each of the first data.

[0179] Optionally, the first calibration module 1010 is specifically used for:

[0180] Determine the coil current of the target atomic magnetometer, and apply a modulation signal of the coil current to the target coil located within the target atomic magnetometer;

[0181] The frequency of the modulation signal is scanned to determine the frequency values ​​at which the response signal of the target atomic magnetometer in response to the static magnetic field crosses zero twice; the static magnetic field is the magnetic field generated by the current in the target coil.

[0182] The first data is determined based on the coil current and the frequency values ​​of the response signal of the target atomic magnetometer in response to the static magnetic field at two zero crossings;

[0183] Update the coil current and return to the step of applying the modulation signal of the coil current to the target coil located within the target atomic magnetometer;

[0184] When the preset second condition is met, the coil constant of the target coil is calculated based on each of the first data.

[0185] Optionally, the first calibration module 1010 is specifically used for:

[0186] The first data are fitted to obtain a first linear relationship between the difference between the fixed parameters and the scanning parameters; the difference between the scanning parameters is determined by the value of the scanning parameters when the response signal of the target atomic magnetometer in response to the static magnetic field crosses zero twice.

[0187] Based on the slope of the first linear relationship, the coil constant of the target coil is calculated;

[0188] Wherein, when the fixed parameter is the frequency of the modulation signal, the scanning parameter is the current of the target coil; and when the fixed parameter is the current of the target coil, the scanning parameter is the frequency of the modulation signal.

[0189] Optionally, the second calibration module 1020 is specifically used for:

[0190] Determine the calibration current and apply the calibration current to the target coil to obtain the response signal voltage of the target atomic magnetometer;

[0191] Based on the coil constant of the target coil and the calibration current, calculate the calibration magnetic field corresponding to the calibration current;

[0192] The second data is determined based on the calibrated magnetic field and the response signal voltage;

[0193] Update the calibration current and return to the step of applying the calibration current to the target coil to obtain the response signal voltage of the target atomic magnetometer;

[0194] When the preset third condition is met, the response coefficient of the target atomic magnetometer is calculated based on each of the second data.

[0195] Each module in the calibration device of the aforementioned atomic magnetometer can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0196] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 11 As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When executed by the processor, the computer program implements a calibration method for an atomic magnetometer. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0197] Those skilled in the art will understand that Figure 11 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0198] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0199] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps in the above method embodiments.

[0200] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0201] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data shall comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0202] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0203] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0204] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A calibration method for an atomic magnetometer, characterized in that, The method comprises: setting an environment parameter of a working environment of a target atomic magnetometer to an environment parameter of a large magnetic field working environment, and setting a working mode of the target atomic magnetometer to an absolute measurement mode, calibrating a target coil located in the target atomic magnetometer to obtain a coil constant of the target coil; setting an environment parameter of a working environment of the target atomic magnetometer to an environment parameter of a near-zero magnetic working environment, and setting a working mode of the target atomic magnetometer to a relative measurement mode, based on the coil constant of the target coil, calibrating the target atomic magnetometer to obtain a response coefficient of the target atomic magnetometer; the response coefficient is used to support the target atomic magnetometer to measure a very weak magnetic field.

2. The method of claim 1, wherein, The setting an environment parameter of a working environment of a target atomic magnetometer to an environment parameter of a large magnetic field working environment, and setting a working mode of the target atomic magnetometer to an absolute measurement mode comprises: in response to a magnetometer measurement instruction, setting an environment parameter of a working environment of a target atomic magnetometer to an environment parameter of a large magnetic field working environment, and setting a working mode of the target atomic magnetometer to an absolute measurement mode; the magnetometer measurement instruction is used to instruct the target atomic magnetometer to measure a magnetic field.

3. The method of claim 1, wherein, The calibrating a target coil located in the target atomic magnetometer to obtain a coil constant of the target coil comprises: determining a frequency of a modulation signal of the target atomic magnetometer, and applying the modulation signal of the frequency on the target coil located in the target atomic magnetometer; scanning a current of the target coil, and determining a current value when a response signal of the target atomic magnetometer in response to a static magnetic field passes zero twice; the static magnetic field is a magnetic field generated by the current of the target coil; determining first data according to the frequency of the modulation signal and the current value when the response signal of the target atomic magnetometer in response to the static magnetic field passes zero twice; updating the frequency of the modulation signal, and returning to the step of applying the modulation signal of the frequency on the target coil located in the target atomic magnetometer; when a preset first condition is met, calculating the coil constant of the target coil according to each first data.

4. The method of claim 1, wherein, The calibrating a target coil located in the target atomic magnetometer to obtain a coil constant of the target coil comprises: determining a coil current of the target atomic magnetometer, and applying a modulation signal of the coil current on the target coil located in the target atomic magnetometer; scanning a frequency of the modulation signal, and determining a frequency value when a response signal of the target atomic magnetometer in response to a static magnetic field passes zero twice; the static magnetic field is a magnetic field generated by the current of the target coil; determining first data according to the coil current and the frequency value when the response signal of the target atomic magnetometer in response to the static magnetic field passes zero twice; updating the coil current, and returning to the step of applying the modulation signal of the coil current on the target coil located in the target atomic magnetometer; when a preset second condition is met, calculating the coil constant of the target coil according to each first data.

5. The method according to any one of claims 3-4, characterized in that, The calculating the coil constant of the target coil according to each of the first data comprises: fitting each of the first data to obtain a first linear relationship between a fixed parameter and a scanning parameter difference; the scanning parameter difference is determined by a value of the scanning parameter when the response signal of the target atomic magnetometer responding to the static magnetic field passes zero twice; calculating the coil constant of the target coil based on a slope of the first linear relationship; wherein, in the case that the fixed parameter is the frequency of the modulation signal, the scanning parameter is the current of the target coil; in the case that the fixed parameter is the current of the target coil, the scanning parameter is the frequency of the modulation signal.

6. The method of claim 1, wherein, The calibrating the target atomic magnetometer based on the coil constant of the target coil to obtain the response coefficient of the target atomic magnetometer comprises: determining a calibration current and applying the calibration current to the target coil to obtain a response signal voltage of the target atomic magnetometer; calculating a calibration magnetic field corresponding to the calibration current based on the coil constant of the target coil and the calibration current; determining second data according to the calibration magnetic field and the response signal voltage; updating the calibration current and returning to the step of applying the calibration current to the target coil to obtain the response signal voltage of the target atomic magnetometer; when a third preset condition is met, calculating the response coefficient of the target atomic magnetometer according to each of the second data.

7. A calibration device for an atomic magnetometer, characterized in that The apparatus comprises: a first calibration module configured to set an environment parameter of a working environment of a target atomic magnetometer to an environment parameter of a large magnetic field working environment, set a working mode of the target atomic magnetometer to an absolute measurement mode, and calibrate a target coil located in the target atomic magnetometer to obtain a coil constant of the target coil; a second calibration module configured to set the environment parameter of the working environment of the target atomic magnetometer to an environment parameter of a near-zero magnetic working environment, set the working mode of the target atomic magnetometer to a relative measurement mode, and calibrate the target atomic magnetometer based on the coil constant of the target coil to obtain a response coefficient of the target atomic magnetometer; the response coefficient is used to support the target atomic magnetometer to measure a very weak magnetic field. 8.A computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the computer device is configured to perform the method according to any one of claims 1-7. The processor executes the computer program to implement the steps of the method of any one of claims 1 to 6.

9. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the method of any one of claims 1 to 6.

10. A computer program product comprising a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the method of any one of claims 1 to 6. The computer program is executed by the processor to implement the steps of the method of any one of claims 1 to 6.

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