Rapid calibration method and device for optimal Raman light angle of atomic gravimeter

Abstract

The invention provides an atomic gravimeter Raman light optimal angle rapid calibration method and device, and the method comprises the steps: selecting a plurality of auxiliary calibration states in a positive and negative preset angle range of an initial calibration state according to the initial calibration state of an atomic gravimeter, and obtaining an auxiliary gravity value corresponding to each auxiliary calibration state, through the value of the preset angle range, the difference between the auxiliary gravity value corresponding to the auxiliary calibration state and the gravitational acceleration of the second place can be almost ignored, so that the auxiliary gravity value corresponding to one of the auxiliary calibration states is regarded as the local gravitational acceleration, and on the basis, the gravitational acceleration of the second place is calculated. According to all the auxiliary calibration states and the auxiliary gravity value corresponding to each auxiliary calibration state, the corresponding optimal calibration state of the atomic gravimeter at the second place is obtained; through the design, a large number of angle points do not need to be scanned and traversed, and the number of the scanned angle points is reduced, so that the data acquisition time is shortened, and the calibration efficiency is greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of atomic gravity measurement technology, and more specifically, relates to a method and apparatus for rapid calibration of the optimal angle of Raman light in an atomic gravimeter. Background Technology

[0002] An atomic gravimeter is an instrument that achieves high-precision measurement of gravitational acceleration based on the principle of atomic interference. Its measurement accuracy is closely related to the parallelism between the Raman beam and the direction of gravity. Therefore, it is necessary to accurately calibrate the probe angle corresponding to the Raman beam to obtain the optimal angle.

[0003] In existing technologies, the parallelism between Raman light and the direction of gravity directly determines the measurement accuracy of an atomic gravimeter. Before leaving the factory, the atomic gravimeter needs to undergo initial calibration to obtain the optimal angle. However, considering that users may need to apply the device to other locations after leaving the factory, and that gravity values ​​vary at different locations on Earth (the maximum absolute gravity difference is approximately 5000 mGal, and the typical difference is about 3000 mGal), the initial calibration state may have errors after the location is changed. Furthermore, considering the structural installation stability of the atomic gravimeter probe and the repeatability and stability of the level, due to external interference and environmental factors, the probe may experience an angle change of 500 μrad in its initial calibration state. Such a change would cause a gravity change of approximately 100 microgal, equivalent to one millionth of the absolute gravity value. Such an error is unacceptable. Therefore, based on the above errors, further angle calibration is required after the atomic gravimeter is moved.

[0004] After the atomic gravimeter undergoes positional relocation, further angle calibration typically employs a "electronic level-assisted + full-angle scan fitting" technique. The core principle is as follows: First, the electronic level monitors the atomic gravimeter probe's attitude in real time, independently modulating the probe's two orthogonal axes (usually defined as the x-axis and y-axis perpendicular to each other on the horizontal plane). During the modulation of each axis, multiple angle points (generally no fewer than 5 points) are continuously or stepwise scanned within a preset angle range (e.g., -3mrad to 3mrad). After adjusting to each angle point, the attitude is stabilized and... The corresponding gravitational acceleration measurement data is collected. Since the parallelism between the Raman beam and the direction of gravity directly affects the magnitude of the gravity measurement, the measured gravity value is the largest when the Raman beam is perfectly parallel to the direction of gravity. When the Raman beam deviates from the parallel direction, the gravity value decreases as the deviation angle increases. Therefore, the collected angle and gravity data will exhibit a typical parabolic trend under angle approximation (with angle as the abscissa and gravity value as the ordinate). Subsequently, the parabolic data is fitted using fitting algorithms such as the least squares method to determine the angle corresponding to the vertex of the parabola. This angle is the optimal angle for this axis, at which point the Raman beam and the direction of gravity are parallel and aligned. However, this method has significant drawbacks: to ensure fitting accuracy, a sufficient number of angle points need to be scanned (usually no less than 10), and the attitude stabilization and data acquisition at each angle point require a certain amount of time, resulting in a long overall calibration process with low efficiency, making it difficult to meet the needs of rapid transport and deployment of atomic gravimeters and real-time on-site measurements.

[0005] Therefore, overcoming the shortcomings of the existing technology is an urgent problem to be solved in this technical field. Summary of the Invention

[0006] The problem this invention aims to solve is how to improve the calibration efficiency of an atomic gravimeter after it has been moved, so as to meet the needs of rapid transport and deployment of the atomic gravimeter and real-time on-site measurement.

[0007] Firstly, a method for rapid calibration of the optimal angle of Raman light in an atomic gravimeter is provided, including: The atomic gravimeter was initially calibrated at the first location to obtain the initial calibration state. Once the atomic gravimeter is located at the second location, multiple auxiliary calibration states are randomly selected within a preset angle range of the initial calibration state, and the corresponding auxiliary gravity value is obtained for each auxiliary calibration state. Based on all auxiliary calibration states and the auxiliary gravity value corresponding to each auxiliary calibration state, the optimal calibration state of the atomic gravimeter at the second location is obtained.

[0008] Preferably, the step of randomly selecting multiple auxiliary calibration states within a preset angle range of the initial calibration state specifically includes: The initial calibration state includes the initial X-axis calibration angle and the initial Y-axis calibration angle; Centered on the initial X-axis calibration angle, a first X-axis auxiliary angle and a second X-axis auxiliary angle are randomly selected within a positive and negative preset angle range; Centered on the initial Y-axis calibration angle, a first Y-axis auxiliary angle and a second Y-axis auxiliary angle are randomly selected within a positive and negative preset angle range; The first X-axis auxiliary angle, the second X-axis auxiliary angle, the first Y-axis auxiliary angle, and the second Y-axis auxiliary angle are all auxiliary calibration states, and the preset angle range is 0.2mrad~20mrad.

[0009] Preferably, obtaining the auxiliary gravity value corresponding to each auxiliary calibration state specifically includes: Keeping the initial Y-axis calibration angle of the atomic gravimeter unchanged, adjust the atomic gravimeter in the X-axis direction to the first X-axis auxiliary angle to obtain the corresponding first auxiliary gravity value; Keeping the initial Y-axis calibration angle of the atomic gravimeter unchanged, adjust the atomic gravimeter in the X-axis direction to the second X-axis auxiliary angle to obtain the corresponding second auxiliary gravity value; Keeping the initial X-axis calibration angle of the atomic gravimeter unchanged, adjust the atomic gravimeter in the Y-axis direction to the first Y-axis auxiliary angle to obtain the corresponding third auxiliary gravity value; Keeping the initial X-axis calibration angle of the atomic gravimeter unchanged, adjust the atomic gravimeter in the Y-axis direction to the second Y-axis auxiliary angle to obtain the corresponding fourth auxiliary gravity value; The first auxiliary gravity value, the second auxiliary gravity value, the third auxiliary gravity value, and the fourth auxiliary gravity value are all the auxiliary gravity values.

[0010] Preferably, obtaining the optimal calibration state of the atomic gravimeter at the second location based on all auxiliary calibration states and the auxiliary gravity value corresponding to each auxiliary calibration state specifically includes: The optimal X-axis calibration angle is obtained based on the first X-axis auxiliary angle, the first auxiliary gravity value, the second X-axis auxiliary angle, and the second auxiliary gravity value. The optimal Y-axis calibration angle is obtained based on the first Y-axis auxiliary angle, the third auxiliary gravity value, the second Y-axis auxiliary angle, and the fourth auxiliary gravity value. The optimal X-axis calibration angle and the optimal Y-axis calibration angle together constitute the optimal calibration state.

[0011] Preferably, obtaining the optimal X-axis calibration angle based on the first X-axis auxiliary angle, the first auxiliary gravity value, the second X-axis auxiliary angle, and the second auxiliary gravity value specifically includes: The first auxiliary gravity value or the second auxiliary gravity value is used as the first approximate gravity value; Obtain the first difference between the first auxiliary gravity value and the second auxiliary gravity value; The optimal X-axis calibration angle is obtained based on the first approximate gravity value, the first difference, the first X-axis auxiliary angle, and the second X-axis auxiliary angle.

[0012] Preferably, obtaining the optimal X-axis calibration angle based on the first approximate gravity value, the first difference, the first X-axis auxiliary angle, and the second X-axis auxiliary angle specifically includes: The expression for the optimal X-axis calibration angle is: ; in, To determine the optimal X-axis calibration angle, The first difference, This is the first approximate value of gravity. This is the first auxiliary angle on the X-axis. This is the second auxiliary angle on the X-axis.

[0013] Preferably, obtaining the optimal Y-axis calibration angle based on the first Y-axis auxiliary angle, the third auxiliary gravity value, the second Y-axis auxiliary angle, and the fourth auxiliary gravity value specifically includes: The third or fourth auxiliary gravity value is used as the second approximate gravity value; Obtain the second difference between the third and fourth auxiliary gravity values; The optimal Y-axis calibration angle is obtained based on the second approximate gravity value, the second difference, the first Y-axis auxiliary angle, and the second Y-axis auxiliary angle.

[0014] Preferably, obtaining the optimal Y-axis calibration angle based on the second approximate gravity value, the second difference, the first Y-axis auxiliary angle, and the second Y-axis auxiliary angle specifically includes: The expression for the optimal Y-axis calibration angle is: ; in, To determine the optimal Y-axis calibration angle, The first difference, This is the first approximate value of gravity. This is the first auxiliary angle along the Y-axis. This is the second auxiliary angle along the Y-axis.

[0015] Secondly, a device for rapid calibration of the optimal angle of Raman light in an atomic gravimeter is provided, comprising at least one processor and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the processor to perform the aforementioned rapid calibration method for the optimal angle of Raman light in an atomic gravimeter.

[0016] Thirdly, the present invention also provides a non-volatile computer storage medium storing computer-executable instructions that are executed by one or more processors to perform the method described in the first aspect.

[0017] Fourthly, a chip is provided, comprising: a processor and an interface for calling and running a computer program stored in memory, performing the method as described in the first aspect.

[0018] Fifthly, a computer program product containing instructions is provided that, when executed on a computer or processor, causes the computer or processor to perform the method as described in the first aspect.

[0019] In a sixth aspect, a rapid calibration system for the optimal angle of Raman light in an atomic gravimeter is provided, comprising the rapid calibration device for the optimal angle of Raman light in an atomic gravimeter as described in the second aspect, and using the rapid calibration method for the optimal angle of Raman light in an atomic gravimeter as described in the first aspect.

[0020] Unlike existing technologies, the present invention has at least the following beneficial effects: Based on the initial calibration state of the atomic gravimeter, multiple auxiliary calibration states are selected within a preset positive and negative angle range of the initial calibration state, and the auxiliary gravity value corresponding to each auxiliary calibration state is obtained. By using the preset angle range, the difference between the auxiliary gravity value corresponding to the auxiliary calibration state and the gravitational acceleration at the second location is almost negligible. Therefore, the auxiliary gravity value corresponding to one of the auxiliary calibration states is regarded as the local gravitational acceleration. Based on this, the optimal calibration state of the atomic gravimeter at the second location is obtained according to all auxiliary calibration states and the auxiliary gravity value corresponding to each auxiliary calibration state. Through the above design, it is not necessary to scan and traverse a large number of angle points, and the data acquisition time is also reduced due to the reduction in the number of angle points scanned, which greatly improves the calibration efficiency. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments of the present invention will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0022] Figure 1 This is a flowchart of a method for rapid calibration of the optimal angle of Raman light in an atomic gravimeter, provided in an embodiment of the present invention. Figure 2 This is a curve showing the fitting relationship between the acquisition points of a rapid calibration method for the optimal angle of Raman light in an atomic gravimeter, provided in an embodiment of the present invention. Figure 3 This is a flowchart of the auxiliary calibration state acquisition method for a rapid calibration method for the optimal angle of Raman light in an atomic gravimeter, provided in an embodiment of the present invention. Figure 4 This is a flowchart illustrating the process of obtaining auxiliary gravity values ​​in a rapid calibration method for the optimal angle of Raman light in an atomic gravimeter, as provided in an embodiment of the present invention. Figure 5 This is a flowchart illustrating the process of obtaining the optimal X-axis calibration angle in a rapid calibration method for Raman light in an atomic gravimeter, as provided in an embodiment of the present invention. Figure 6 This is a flowchart illustrating the process of obtaining the optimal Y-axis calibration angle in a rapid calibration method for Raman light in an atomic gravimeter, as provided in an embodiment of the present invention. Figure 7 This is a graph showing the relationship between gravity difference and deviation angle at different locations in a rapid calibration method for the optimal angle of Raman light in an atomic gravimeter, provided by an embodiment of the present invention. Figure 8 This is a graph showing the relationship between angle change and gravity value along the X-axis in one embodiment of a rapid calibration method for the optimal angle of Raman light in an atomic gravimeter provided by this invention. Figure 9 This is a graph showing the relationship between angle change and gravity value along the Y-axis in one embodiment of a rapid calibration method for the optimal angle of Raman light in an atomic gravimeter provided by this invention. Figure 10 This is a schematic diagram of a device for rapid calibration of the optimal angle of Raman light in an atomic gravimeter, provided in an embodiment of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0024] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as openly inclusive, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples; that is, although they may be incorporated into embodiments or examples using the above terms for reasons such as order and position, it does not limit them to be incorporated in combination by a single embodiment or example.

[0025] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more. Furthermore, for example, the description may use the prefix "A" or "B" to describe the same type of nouns as two independent entities. In this case, the corresponding features defined with "A" and "B" are used only to distinguish between similar entities and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features.

[0026] In the description of this invention, the expression “A and / or B” (where A and B are used to formally represent specific features) will be used. The corresponding expression includes the following three combinations: only A, only B, and a combination of A and B.

[0027] As used in this invention, “about,” “approximately,” or “approximately” includes the stated value and the average value within an acceptable range of deviation from a particular value, wherein the acceptable range of deviation is determined by a person skilled in the art taking into account the measurement under discussion and the error associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0028] Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] Example 1: This embodiment provides a method for rapid calibration of the optimal angle of Raman light in an atomic gravimeter, such as... Figure 1 As shown, the method flow includes the following.

[0030] In step 101, the atomic gravimeter is initially calibrated at the first location to obtain the initial calibration state.

[0031] The application scenario of this embodiment is that the atomic gravimeter achieves high-precision measurement of gravitational acceleration based on the principle of atomic interference. During this process, the Raman light emitted by the atomic gravimeter needs to be as parallel as possible to the direction of gravity to ensure measurement accuracy. When there is an angle between the Raman light emitted by the atomic gravimeter and the direction of gravity, the gravitational acceleration measured by the atomic gravimeter is the component of the local gravitational acceleration, i.e., g = g0cosα, where g is the gravitational acceleration measured by the atomic gravimeter, g0 is the local gravitational acceleration, and α is the angle (i.e., deviation angle) between the Raman light and the direction of gravity. When α is close to 0, the expression g = g0cosα can be approximated as g = g0(1-α). 2 / 2), the curve showing the relationship between the difference between the gravitational acceleration measured by the atomic gravimeter and the local gravitational acceleration and the deviation angle is as follows: Figure 2 As shown, it is therefore necessary to calibrate the tilt angle of the probe emitting Raman light so that the direction of Raman light emission is as parallel as possible to the direction of gravity, in order to ensure the accuracy of subsequent measurements by the atomic gravimeter.

[0032] In this embodiment, the atomic gravimeter typically undergoes an initial calibration at the factory. This initial calibration is used to pre-adjust the probe of the atomic gravimeter to be parallel to the direction of gravity, avoiding the need for subsequent operators to perform extensive angle traversal to determine the state of the atomic gravimeter. The initial calibration can be performed using a traditional scanning fitting method, traversing a certain angle range with a preset angle step size. For each traversed angle state, the gravitational acceleration data for that current state needs to be measured. The larger the measured gravitational acceleration, the closer the probe is to being parallel to the direction of gravity. After obtaining a relatively optimal angle state, a more precise traversal with smaller angle steps can be performed within a certain positive and negative interval (the positive and negative interval is smaller than the preset angle step). During this traversal, the gravitational acceleration data for the corresponding state is also measured, thereby obtaining a more optimal angle state. This process can be repeated multiple times to obtain a relatively ideal angle state, which is the initial calibration state—the state where the probe of the atomic gravimeter is closest to being parallel to the direction of gravity at the first location.

[0033] Furthermore, considering that users need to apply the atomic gravimeter to other locations after it leaves the factory, but the gravity values ​​at different locations on Earth vary, with the maximum absolute gravity difference being approximately 5000 mGal and the typical difference being approximately 3000 mGal, this can lead to errors in the initial calibration state after the location is changed. Moreover, considering the structural installation stability of the probe in a practical atomic gravimeter, as well as the repeatability and stability of the level, due to external interference and environmental factors, the probe may experience an angle change of 500 μrad in its initial calibration state. Such a change would cause a gravity change of approximately 100 microgal, equivalent to one millionth of the absolute gravity value. Such an error change is unacceptable. Therefore, this embodiment requires further angle calibration at the corresponding location based on the aforementioned errors to reduce the error of the atomic gravimeter. Thus, this embodiment also involves the following steps.

[0034] In step 102, after the atomic gravimeter is located at the second location, multiple auxiliary calibration states are randomly selected within the preset angle range of the initial calibration state, and the auxiliary gravity value corresponding to each auxiliary calibration state is obtained.

[0035] In step 103, the optimal calibration state of the atomic gravimeter at the second location is obtained based on all auxiliary calibration states and the auxiliary gravity value corresponding to each auxiliary calibration state.

[0036] In this embodiment, the preset angle range is set by those skilled in the art based on actual conditions. In this embodiment, the preset angle range is 0.2 mrad to 20 mrad, and the preferred range is 1 mrad to 2 mrad. The auxiliary calibration state is as follows: taking the initial calibration state as the center, multiple adjustment angles are randomly selected in the X-axis direction within the positive and negative preset angle range for adjustment, which are the corresponding multiple auxiliary calibration states; similarly, taking the initial calibration state as the center, multiple adjustment angles are randomly selected in the Y-axis direction within the positive and negative preset angle range for adjustment, which are the corresponding multiple auxiliary calibration states; for each auxiliary calibration state, the corresponding gravity value is measured, which is the auxiliary gravity value corresponding to the corresponding auxiliary calibration state.

[0037] Because the variation trend of gravity varies by approximately 2 μGal within the preset angle range, and the best measurement uncertainty for an absolute gravimeter is currently 2 μGal, this difference in the variation trend of gravity relative to the angle will not affect the actual measurement results. Since the preset angle range is too small, in this embodiment, the difference between the auxiliary gravity value corresponding to the auxiliary calibration state and the local gravitational acceleration is almost negligible. Therefore, in the X-axis or Y-axis dimension, the auxiliary gravity value corresponding to one of the auxiliary calibration states can be regarded as the local gravitational acceleration. Based on the approximate local gravitational acceleration, all auxiliary calibration states, and the auxiliary gravity value corresponding to each auxiliary calibration state, the optimal calibration state of the atomic gravimeter at the second location is calculated. The optimal calibration state is the optimal angle state of the atomic gravimeter probe relative to the vertical direction at the corresponding location.

[0038] In this embodiment, based on the initial calibration state of the atomic gravimeter, multiple auxiliary calibration states are selected within a preset positive and negative angle range of the initial calibration state, and the auxiliary gravity value corresponding to each auxiliary calibration state is obtained. Due to the preset angle range, the difference between the auxiliary gravity value corresponding to the auxiliary calibration state and the local gravitational acceleration is almost negligible. Therefore, the auxiliary gravity value corresponding to one of the auxiliary calibration states can be regarded as the local gravitational acceleration. Based on this, the optimal calibration state of the atomic gravimeter at the second location is obtained according to all auxiliary calibration states and the auxiliary gravity value corresponding to each auxiliary calibration state. It is not necessary to scan and traverse a large number of angle points, and the data acquisition time is also reduced due to the reduction in the number of angle points scanned, which greatly improves the calibration efficiency.

[0039] Furthermore, in this embodiment, considering that when adjusting the probe of the atomic gravimeter to change its tilt angle relative to the direction of gravity, it is necessary to adjust the probe angle in both the X-axis and Y-axis directions, similarly, selecting multiple auxiliary calibration states based on the initial calibration state also requires angle adjustments in both the X-axis and Y-axis directions. Therefore, this embodiment also involves the following design: randomly selecting multiple auxiliary calibration states within a preset angle range of the initial calibration state, such as... Figure 3 As shown, the method flow includes: In step 201, the initial calibration state includes an initial X-axis calibration angle and an initial Y-axis calibration angle. Taking the initial X-axis calibration angle as the center, a first X-axis auxiliary angle and a second X-axis auxiliary angle are randomly selected within a positive and negative preset angle range.

[0040] In this embodiment, the first X-axis auxiliary angle and the second X-axis auxiliary angle are respectively taken within the preset angle range on both sides of the initial X-axis calibration angle. Therefore, the difference between the first X-axis auxiliary angle, the second X-axis auxiliary angle and the initial X-axis calibration angle are all within the preset angle range.

[0041] In step 202, with the initial Y-axis calibration angle as the center, a first Y-axis auxiliary angle and a second Y-axis auxiliary angle are randomly selected within a positive and negative preset angle range.

[0042] In this embodiment, within a preset angle range on both sides of the initial X-axis calibration angle, the first Y-axis auxiliary angle and the second Y-axis auxiliary angle are respectively taken. Therefore, the difference between the first Y-axis auxiliary angle, the second Y-axis auxiliary angle and the initial Y-axis calibration angle are all within the preset angle range.

[0043] In step 203, the first X-axis auxiliary angle, the second X-axis auxiliary angle, the first Y-axis auxiliary angle, and the second Y-axis auxiliary angle are all in the auxiliary calibration state, and the preset angle range is 0.2mrad~20mrad.

[0044] Furthermore, in this embodiment, when actually adjusting the state of the atomic gravimeter, adjustments need to be made separately along the X-axis and Y-axis to ensure that the probe of the atomic gravimeter reaches the specified tilt angle. The corresponding adjustment method is as follows: The auxiliary gravity value corresponding to each auxiliary calibration state is obtained, such as... Figure 4 As shown, the method flow includes the following.

[0045] In step 301, the atomic gravimeter is kept at its initial Y-axis calibration angle, and the atomic gravimeter is adjusted to the first X-axis auxiliary angle in the X-axis direction to obtain the corresponding first auxiliary gravity value.

[0046] In step 302, the atomic gravimeter is kept at its initial Y-axis calibration angle, and then the atomic gravimeter is adjusted to the second X-axis auxiliary angle in the X-axis direction to obtain the corresponding second auxiliary gravity value.

[0047] In step 303, the atomic gravimeter is kept at its initial X-axis calibration angle, and the atomic gravimeter is adjusted to the first Y-axis auxiliary angle in the Y-axis direction to obtain the corresponding third auxiliary gravity value.

[0048] In step 304, the atomic gravimeter is kept at its initial X-axis calibration angle, and then the atomic gravimeter is adjusted to the second Y-axis auxiliary angle in the Y-axis direction to obtain the corresponding fourth auxiliary gravity value.

[0049] In step 305, the first auxiliary gravity value, the second auxiliary gravity value, the third auxiliary gravity value, and the fourth auxiliary gravity value are all the auxiliary gravity values.

[0050] It is important to note that when adjusting the probe of an atomic gravimeter in both the X and Y axes from its initial calibration state, if adjusting along the X axis, keep the probe constant along the Y axis and rotate it around the Y axis to adjust the angle along the X axis, thus adjusting to the corresponding first and second auxiliary X-axis angles. If adjusting along the Y axis, keep the probe constant along the X axis and rotate it around the X axis to adjust the angle along the Y axis, thus adjusting to the corresponding first and second auxiliary Y-axis angles.

[0051] Furthermore, in this embodiment, after obtaining the auxiliary gravity values ​​corresponding to each auxiliary angle, since the difference between the auxiliary gravity values ​​and the local gravity values ​​in the X-axis and Y-axis dimensions is negligible, based on the above, according to the expression g=g0(1-α) 2 / 2), the ideal calibration angles corresponding to the X-axis and Y-axis dimensions can be calculated respectively. Thus, at the second location, by adjusting the tilt angle of the probe, the probe and the direction of gravity can be made to approach parallelism. The corresponding design is as follows: Based on all auxiliary calibration states and the auxiliary gravity value corresponding to each auxiliary calibration state, the optimal calibration state of the atomic gravimeter at the second location is obtained. Specifically, this includes: obtaining the optimal X-axis calibration angle based on the first X-axis auxiliary angle, the first auxiliary gravity value, the second X-axis auxiliary angle, and the second auxiliary gravity value; obtaining the optimal Y-axis calibration angle based on the first Y-axis auxiliary angle, the third auxiliary gravity value, the second Y-axis auxiliary angle, and the fourth auxiliary gravity value; the optimal X-axis calibration angle and the optimal Y-axis calibration angle together serve as the optimal calibration state.

[0052] Furthermore, in this embodiment, the angle calibration along the X-axis needs to be calculated based on the selected first X-axis auxiliary angle and second X-axis auxiliary angle. The corresponding design is as follows: the optimal X-axis calibration angle is obtained based on the first X-axis auxiliary angle, the first auxiliary gravity value, the second X-axis auxiliary angle, and the second auxiliary gravity value, such as... Figure 5 As shown, the method flow includes the following.

[0053] In step 401, the first auxiliary gravity value or the second auxiliary gravity value is used as the first approximate gravity value.

[0054] In step 402, the first difference between the first auxiliary gravity value and the second auxiliary gravity value is obtained.

[0055] In step 403, the optimal X-axis calibration angle is obtained based on the first approximate gravity value, the first difference, the first X-axis auxiliary angle, and the second X-axis auxiliary angle.

[0056] When the first auxiliary gravity value is used as the first approximate gravity value, the process of solving the optimal X-axis calibration angle is as follows: = - = (1- )- (1- ); ; ; In summary, the expression for the optimal X-axis calibration angle is: ; in, To determine the optimal X-axis calibration angle, The first difference, This is the first auxiliary gravity value (i.e., the first approximate gravity value). This is the second auxiliary gravity value. This is the first auxiliary angle on the X-axis. This is the second auxiliary angle on the X-axis. Due to local gravitational acceleration, Therefore, in the above formula can be or Substitution, that is , The unit is mrad. and The unit is , and The unit is rad.

[0057] Furthermore, in this embodiment, the angle calibration along the Y-axis needs to be calculated based on the selected first Y-axis auxiliary angle and second Y-axis auxiliary angle. The corresponding design is as follows: the optimal Y-axis calibration angle is obtained based on the first Y-axis auxiliary angle, the third auxiliary gravity value, the second Y-axis auxiliary angle, and the fourth auxiliary gravity value, such as... Figure 6 As shown, the method flow includes the following.

[0058] In step 501, the third auxiliary gravity value or the fourth auxiliary gravity value is used as the second approximate gravity value.

[0059] In step 502, the second difference between the third auxiliary gravity value and the fourth auxiliary gravity value is obtained.

[0060] In step 503, the optimal Y-axis calibration angle is obtained based on the second approximate gravity value, the second difference, the first Y-axis auxiliary angle, and the second Y-axis auxiliary angle.

[0061] When the third auxiliary gravity value is used as the second approximate gravity value, the process of solving for the optimal Y-axis calibration angle is as follows: = - = (1- )- (1- ); ; ; In summary, the expression for the optimal Y-axis calibration angle is: ; in, To determine the optimal X-axis calibration angle, The first difference, This is the third auxiliary gravity value (i.e., the second approximate gravity value). This is the fourth auxiliary gravity value. This is the first auxiliary angle along the Y-axis. This is the second auxiliary angle along the Y-axis. Due to local gravitational acceleration, Therefore, in the above formula can be or Substitution, that is , The unit is mrad. and The unit is , and The unit is rad.

[0062] Adjust the x-axis and y-axis of the atomic gravimeter probe to the calculated optimal angles. and This allows for the parallel alignment of the Raman beam with the direction of gravity, enabling rapid calibration of the optimal angle of the Raman beam at the second location using an atomic gravimeter.

[0063] In summary, in this embodiment, after the atomic gravimeter is transported and redeployed, the tilt angle of the Raman light may deviate from its pre-transport value due to stress and external environmental factors during the transport process. Considering the structural installation stability of the probe of a practical atomic gravimeter, as well as the repeatability and stability of the high-precision level, the change in its optimal angle after transport and redeployment is generally within 500 μrad. This change will cause a maximum gravitational change of approximately 100 microgals, relative to the absolute gravity value (generally 9.78~9.83 m / s²). 2The relative change (between two points) is approximately one part per million, which is an intolerable error. Therefore, after the atomic gravimeter is moved and redeployed, it needs to be recalibrated based on the original calibration. The maximum difference in absolute gravity values ​​between different locations on Earth is approximately 5000 mGal. In regional gravity measurements, the difference in gravity values ​​between different locations generally does not exceed 3000 mGal. Calculations show that the trend curve of gravity relative to the deviation angle after movement is almost identical to the trend curve at the optimal angle at the original location at small angles. Figure 7 As shown, Figure 7 The horizontal axis represents the deviation angle, and the vertical axis represents the difference between the gravitational acceleration before and after transport, under the same deflection angle. The curves in the figure show the gravitational deviation between the gravitational acceleration before and after transport and the deviation angle for different absolute gravity values. The figure shows that when the absolute gravity value difference is 3000 mGal, the gravity difference is approximately 2 μGal for a deviation angle of ±1 mrad. Currently, the best measurement uncertainty for an absolute gravimeter is 2 μGal. Therefore, the difference in the trend of gravity variation with deviation angle within the corresponding interval does not affect the actual measurement results and can be ignored.

[0064] A consistency comparison was made between the angle modulation fitting of the traditional method and the method of this embodiment: the optimal X-axis calibration angle obtained by the traditional method was 0.811 mrad and the optimal Y-axis calibration angle was 1.192 mrad. Figure 8 This is a curve showing the relationship between different auxiliary angles and gravity values ​​along the X-axis. Figure 9 This is a curve showing the relationship between different auxiliary angles and gravity values ​​along the Y-axis. Figure 8 and Figure 9 The relationship curves in the figure are all fitted from the collected points in the graph, using... Figure 8 and Figure 9 The optimal X-axis calibration angle for the second and fourth data acquisition points was calculated to be 0.799 mrad and the optimal Y-axis calibration angle was 1.196 mrad using the method described in this embodiment. Figure 8 and Figure 9 The first and fifth data collection points were calculated using the method of this embodiment, and the optimal X-axis calibration angle was found to be 0.813 mrad and the optimal Y-axis calibration angle was found to be 1.193 mrad. It can be seen that the maximum error between the results obtained in this embodiment and the traditional method is only 12 μrad, and the corresponding gravity error is much less than 1 μGal, which can be ignored.

[0065] In summary, this embodiment provides the following beneficial effects: 1. Significantly improved calibration efficiency: Traditional methods require scanning more than 10 angle points and fitting, while the method in this embodiment only needs to collect 4 points in the X-axis and Y-axis dimensions to complete the calibration, reducing data acquisition and processing time by 60%, which greatly meets the measurement needs of rapid transport and deployment of atomic gravimeters.

[0066] 2. Controllable calibration accuracy: The angle deviation between this method and the traditional fitting method is controlled within 20 μrad, corresponding to a gravity measurement deviation of less than 1 μGal, which fully meets the high-precision measurement requirements of the atomic gravimeter.

[0067] 3. Simplified operation process: No complicated full-angle scanning and fitting operations are required. Only simple two-point angle adjustment and numerical calculation are needed, which reduces the technical threshold for operators and improves the practicality and convenience of the instrument.

[0068] Example 2: like Figure 10 The diagram shown is a schematic representation of a rapid calibration device for the optimal angle of Raman light in an atomic gravimeter according to an embodiment of the present invention. This rapid calibration device for the optimal angle of Raman light in an atomic gravimeter includes one or more processors 41 and a memory 42.

[0069] Processor 41 and memory 42 can be connected via a bus or other means. Figure 10 Taking the example of a connection between China and Israel via a bus.

[0070] The memory 42, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs and non-volatile computer-executable programs, such as the rapid calibration method for the optimal angle of Raman light in the atomic gravimeter in the above embodiment. The processor 41 executes the rapid calibration method for the optimal angle of Raman light in the atomic gravimeter by running the non-volatile software program and instructions stored in the memory 42.

[0071] Memory 42 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, memory 42 may optionally include memory remotely located relative to processor 41, which can be connected to processor 41 via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0072] The program instructions / modules are stored in the memory 42. When executed by one or more processors 41, they perform the rapid calibration method for the optimal angle of the Raman light of the atomic gravimeter in the above embodiment.

[0073] This invention also provides a computer storage medium storing computer program instructions; when executed by a processor, these computer program instructions implement the rapid calibration method for the optimal angle of Raman light in an atomic gravimeter provided in this invention.

[0074] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements 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 for rapid calibration of the optimal angle of Raman light in an atomic gravimeter, characterized in that, include: The atomic gravimeter was initially calibrated at the first location to obtain the initial calibration state. Once the atomic gravimeter is located at the second location, multiple auxiliary calibration states are randomly selected within a preset angle range of the initial calibration state, and the corresponding auxiliary gravity value is obtained for each auxiliary calibration state. Based on all auxiliary calibration states and the auxiliary gravity value corresponding to each auxiliary calibration state, the optimal calibration state of the atomic gravimeter at the second location is obtained.

2. The method for rapid calibration of the optimal angle of Raman light in an atomic gravimeter according to claim 1, characterized in that, The step of randomly selecting multiple auxiliary calibration states within a preset angle range of the initial calibration state specifically includes: The initial calibration state includes the initial X-axis calibration angle and the initial Y-axis calibration angle; Centered on the initial X-axis calibration angle, a first X-axis auxiliary angle and a second X-axis auxiliary angle are randomly selected within a positive and negative preset angle range; Centered on the initial Y-axis calibration angle, a first Y-axis auxiliary angle and a second Y-axis auxiliary angle are randomly selected within a positive and negative preset angle range; The first X-axis auxiliary angle, the second X-axis auxiliary angle, the first Y-axis auxiliary angle, and the second Y-axis auxiliary angle are all auxiliary calibration states, and the preset angle range is 0.2mrad~20mrad.

3. The method for rapid calibration of the optimal angle of Raman light in an atomic gravimeter according to claim 2, characterized in that, The step of obtaining the auxiliary gravity value corresponding to each auxiliary calibration state specifically includes: Keeping the initial Y-axis calibration angle of the atomic gravimeter unchanged, adjust the atomic gravimeter in the X-axis direction to the first X-axis auxiliary angle to obtain the corresponding first auxiliary gravity value; Keeping the initial Y-axis calibration angle of the atomic gravimeter unchanged, adjust the atomic gravimeter in the X-axis direction to the second X-axis auxiliary angle to obtain the corresponding second auxiliary gravity value; Keeping the initial X-axis calibration angle of the atomic gravimeter unchanged, adjust the atomic gravimeter in the Y-axis direction to the first Y-axis auxiliary angle to obtain the corresponding third auxiliary gravity value; Keeping the initial X-axis calibration angle of the atomic gravimeter unchanged, adjust the atomic gravimeter in the Y-axis direction to the second Y-axis auxiliary angle to obtain the corresponding fourth auxiliary gravity value; The first auxiliary gravity value, the second auxiliary gravity value, the third auxiliary gravity value, and the fourth auxiliary gravity value are all the auxiliary gravity values.

4. The method for rapid calibration of the optimal angle of Raman light in an atomic gravimeter according to claim 3, characterized in that, The process of obtaining the optimal calibration state of the atomic gravimeter at the second location based on all auxiliary calibration states and the auxiliary gravity value corresponding to each auxiliary calibration state specifically includes: The optimal X-axis calibration angle is obtained based on the first X-axis auxiliary angle, the first auxiliary gravity value, the second X-axis auxiliary angle, and the second auxiliary gravity value. The optimal Y-axis calibration angle is obtained based on the first Y-axis auxiliary angle, the third auxiliary gravity value, the second Y-axis auxiliary angle, and the fourth auxiliary gravity value. The optimal X-axis calibration angle and the optimal Y-axis calibration angle together constitute the optimal calibration state.

5. The method for rapid calibration of the optimal angle of Raman light in an atomic gravimeter according to claim 4, characterized in that, The process of obtaining the optimal X-axis calibration angle based on the first X-axis auxiliary angle, the first auxiliary gravity value, the second X-axis auxiliary angle, and the second auxiliary gravity value specifically includes: The first auxiliary gravity value or the second auxiliary gravity value is used as the first approximate gravity value; Obtain the first difference between the first auxiliary gravity value and the second auxiliary gravity value; The optimal X-axis calibration angle is obtained based on the first approximate gravity value, the first difference, the first X-axis auxiliary angle, and the second X-axis auxiliary angle.

6. The method for rapid calibration of the optimal angle of Raman light in an atomic gravimeter according to claim 5, characterized in that, The process of obtaining the optimal X-axis calibration angle based on the first approximate gravity value, the first difference, the first X-axis auxiliary angle, and the second X-axis auxiliary angle specifically includes: The expression for the optimal X-axis calibration angle is: ； in, To determine the optimal X-axis calibration angle, The first difference, This is the first approximate value of gravity. This is the first auxiliary angle on the X-axis. This is the second auxiliary angle on the X-axis.

7. The method for rapid calibration of the optimal angle of Raman light in an atomic gravimeter according to claim 4, characterized in that, The process of obtaining the optimal Y-axis calibration angle based on the first Y-axis auxiliary angle, the third auxiliary gravity value, the second Y-axis auxiliary angle, and the fourth auxiliary gravity value specifically includes: The third or fourth auxiliary gravity value is used as the second approximate gravity value; Obtain the second difference between the third and fourth auxiliary gravity values; The optimal Y-axis calibration angle is obtained based on the second approximate gravity value, the second difference, the first Y-axis auxiliary angle, and the second Y-axis auxiliary angle.

8. The method for rapid calibration of the optimal angle of Raman light in an atomic gravimeter according to claim 7, characterized in that, The process of obtaining the optimal Y-axis calibration angle based on the second approximate gravity value, the second difference, the first Y-axis auxiliary angle, and the second Y-axis auxiliary angle specifically includes: The expression for the optimal Y-axis calibration angle is: ； in, To determine the optimal Y-axis calibration angle, The first difference, This is the first approximate value of gravity. This is the first auxiliary angle along the Y-axis. This is the second auxiliary angle along the Y-axis.

9. A rapid calibration device for the optimal angle of Raman light in an atomic gravimeter, characterized in that, The method includes at least one processor and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the processor for performing the rapid calibration method for optimal Raman light of an atomic gravimeter according to any one of claims 1-8.

10. A non-volatile computer storage medium, characterized in that, The computer storage medium stores computer program instructions, which, when executed by one or more processors, implement the rapid calibration method for the optimal angle of Raman light in an atomic gravimeter as described in any one of claims 1-8.

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