CN114527520A - Vibration compensation method for correcting interference fringes of atomic interference gravimeter - Google Patents

Abstract

The invention discloses a vibration compensation method for correcting interference fringes of an atomic interference gravimeter, comprising the following steps: S1, a given frequency sweep rate sequence, a gravity reference value, a pulse interval duration, and an effective wave vector; S2, importing measured data ; S3, calculate and set the optimization target through the original stripes; S4, divide the vibration sensor signal according to the trigger signal, and obtain the vibration sensor signal corresponding to each transition probability; S5, give the starting range of the delay coefficient and the gain coefficient; S6 , Obtain the optimal delay coefficient and the optimal gain coefficient through the traversal search method or the golden section search method; S7, calculate the vibration speed of the reference mirror during each atomic interference through the optimal delay coefficient and the optimal gain coefficient, and then obtain The vibrational phase noise sequence, the atomic phase sequence only affected by vibrations, and the correction fringe are finally calculated to obtain the RMSE value when the correction fringe is fitted to the standard cosine signal.

Description

A vibration compensation method for correcting interference fringes of atomic interference gravimeter

technical field

The invention relates to the field of gravity measurement, in particular to a vibration compensation method for correcting interference fringes of an atomic interference gravimeter.

Background technique

Absolute gravity measurement, that is, the precise measurement of the absolute value of gravitational acceleration, has a wide range of applications in the fields of auxiliary navigation, resource exploration, geophysics, and measurement. Existing high-precision absolute gravimeters generally use the free-fall method, mainly including laser interferometric absolute gravimeters with corner prisms as falling objects and atomic interferometric absolute gravimeters with cold atomic clusters as falling objects, hereinafter referred to as optics. gravimeter and atomic gravimeter. The former uses a laser interferometer to measure the free-falling trajectory of the corner cube in vacuum, and fits and solves the gravitational acceleration. . Since the actual measurement object of the two is the motion acceleration of the falling object or the falling atomic group relative to a reference mirror (corner prism or plane mirror) in the instrument, the acceleration of the reference mirror itself must be coupled to the measurement result. Theoretically, when the vibration of the reference mirror itself is ignored, the measurement accuracy of the existing absolute gravimeter can reach the micro-gamma level; but in fact, if the reference mirror is directly placed on the ground, the dispersion of the measurement value caused by the ground vibration will exceed Ten microGal, even in the complex vibration environment, it can even reach the order of milliGal or ten milliGal. Therefore, it is one of the effective means to improve the measurement accuracy of the absolute gravimeter to obtain the motion acceleration of the reference mirror itself and to correct its influence when calculating the gravitational acceleration. This correction method is generally called vibration compensation.

Specifically, the ground vibration noise affecting the atomic gravimeter is mainly environmental noise, which is related to the measurement time and the foundation, coordinates and environment of the measurement point, and can be roughly distinguished according to the frequency. The first is human activity noise, generally greater than 1Hz, such as the movement of nearby people during the instrument test, the vibration generated by artificial vibration sources such as vehicles, and the shaking of buildings. The second is the noise originating from the earth itself, generally between 0.1Hz and 1Hz, mainly including vibrations caused by periodic pulsations and earthquakes and other internal movements of the earth. The acceleration power spectral density of the ground pulsation noise model is at frequencies of 0.2Hz and There is a peak at 3Hz. Finally, atmospheric motion noise such as pressure fluctuations, generally less than 0.1 Hz, generally changes slowly and has a low amplitude, and its impact on absolute gravity measurements can be ignored. Since the absolute gravity measurement only relies on the displacement data in the vertical direction for calculation, the horizontal component of ground vibration is generally ignored when the vibration compensation of atomic interference fringes is performed, and only the vertical vibration signal output by the vibration measuring instrument is used.

At present, the relatively mature atomic gravimeter in the world is the CAG-01 atomic gravimeter developed by the Paris Observatory in France. It has participated in many international gravity comparisons. The vibration processing method adopted is the combination of passive vertical vibration isolation system and vibration compensation. The specific principle of vibration compensation is: the data acquisition card synchronously records the velocity signal output by the seismometer and the atomic interference fringes in the process of atomic interference, and uses the IIR (Infinite Impulse Response, infinite impulse response) filter and non-causal in the control software. The low-pass filter processes the seismometer signal to reduce the influence of the non-constant amplitude-frequency characteristics of the seismometer transfer function and the nonlinear phase-frequency characteristics, so as to obtain a more realistic reference mirror vibration signal. The atomic interference fringes are corrected with reference to the phase noise introduced by the mirror vibration. In the measurement environment in which the instrument is located, the vibration compensation method itself can triple the sensitivity of the gravimeter. The University of Hannover in Germany proposes to use digital low-pass and high-pass filters to pre-process the output signal of the vibration sensor to obtain a more accurate reference mirror vibration induced phase noise, so as to achieve vibration compensation. The experimental results show that the use of high-precision commercial seismometers for vibration compensation in quiet environments, or the use of low-precision commercial accelerometers or their self-developed new optical inertial sensors for compensation in complex vibration environments can be effective. Increase the sensitivity of the gravimeter.

In my country, the self-made atomic gravimeter of Zhejiang University also adopts the vibration compensation method. Its main feature is to use commercial inversion software to correct the influence of the measured transfer function of the seismometer to obtain a more realistic reference mirror vibration signal (as shown in Figure 1). . In its laboratory setting, the method can increase the sensitivity of gravimeters to levels similar to when passive vibration isolation systems are used. The National University of Defense Technology has carried out a detailed analysis of the measurement noise caused by the vertical vibration and horizontal deflection of the reference mirror. The accelerometer is used to measure the vibration of the reference mirror when the atomic gravimeter is working, and the transfer function between the accelerometer and the reference mirror is compared. Precise calibration. The measured results show that the vibration compensation method can achieve a significant vibration compensation effect in a complex vibration environment. The vibration compensation method proposed by the National Defense Innovation Institute of the Academy of Military Sciences uses a Michelson laser interferometer with a high-precision four-channel phase-shift detector to replace the traditional vibration sensor. The interferometer can directly measure the phase shift of the atomic interference fringes, and combine the signal shaping and digital phase identification methods to determine the change of the phase fraction of the atomic interference fringes before and after the Raman laser pulse, and obtain the atomic interference phase deviation caused by the vibration of the reference mirror. By removing the phase deviation, the transition probability signal measured by the gravimeter can be corrected. In addition, China Institute of Metrology, Chinese Academy of Sciences Institute of Precision Measurement, Huazhong University of Science and Technology, University of Science and Technology of China, National University of Defense Technology, Stanford University, Humboldt University in Germany and other units have also developed different types of vibration isolation systems to reduce ground The effect of vibrations on an atomic gravimeter.

However, the existing atomic gravimeter has poor adaptability, and its vibration compensation effect is obviously reduced when the measurement environment changes, thus affecting the measurement accuracy of the atomic gravimeter, so it is necessary to improve it.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the above problems, and to provide a vibration compensation method for correcting the interference fringes of an atomic interference gravimeter, which has the best compensation effect in each measurement environment.

In order to achieve the above object, the technical scheme of the present invention is:

A vibration compensation method for correcting interference fringes of an atomic interference gravimeter, comprising the following steps:

S1. Given sweep rate sequence, gravity reference value, pulse interval duration, and effective wave vector;

S2. Import the measured data;

S3. Calculate and set the optimization goal through the original stripe;

S4. Divide the vibration sensor signal according to the trigger signal, and obtain the vibration sensor signal corresponding to each transition probability;

S5, the starting range of the given delay coefficient and gain coefficient;

S6. Obtain the optimal delay coefficient and the optimal gain coefficient through the traversal search method or the golden section search method;

S7. Calculate the vibration speed of the reference mirror during each atomic interference through the optimal delay coefficient and optimal gain coefficient, and then obtain the vibration phase noise sequence, the atomic phase sequence only affected by vibration, and the correction fringes, and finally calculate the correction fringes. RMSE value when fitted to a standard cosine signal.

Further, in the step S2, the measured data includes the measured transition probability sequence corresponding to the frequency sweep rate sequence, the vertical output signal of the vibration sensor measuring the vibration of the reference mirror in the same period, and the trigger signal before each atomic group falls in the same period. .

Further, in the step S3, the optimization targets are the RMSE value during the original fringe fitting, the coefficient of determination during the original fringe fitting, the standard deviation of the interference fringe residual, the original fringe residual and the fringe only affected by vibration. One of the correlation coefficients between residuals.

Further, in the step S4, a filter processing operation is performed on the vibration sensor signal with the corrector transfer function.

Further, in the step S6, when the optimal delay coefficient and the optimal gain coefficient are obtained by using the traversal search method or the golden section search method, when the optimization target is the RMSE value of the original stripe fitting, the original stripe fitting is used as the RMSE value. The delay coefficient and gain coefficient corresponding to the time when the RMSE value reaches the minimum value are regarded as the optimal delay coefficient and optimal gain coefficient;

When the optimization target is the coefficient of determination in the original fringe fitting, the delay coefficient and gain coefficient corresponding to when the coefficient of determination in the original fringe fitting reaches the minimum value are used as the optimal delay coefficient and optimal gain coefficient;

When the optimization target is the standard deviation of the interference fringe residual, the delay coefficient and gain coefficient corresponding to when the standard deviation of the interference fringe residual reaches the minimum value are taken as the optimal delay coefficient and optimal gain coefficient;

When the optimization objective is the correlation coefficient between the original fringe residual and the fringe residual only affected by vibration, the absolute value of the correlation coefficient between the original fringe residual and the fringe residual only affected by vibration reaches the maximum value The corresponding delay coefficient is used as the optimal delay coefficient; the corresponding gain coefficient when other optimization targets reach the minimum value is used as the optimal gain coefficient.

Further, in the step S7, when calculating the vibration velocity of the reference mirror during each atomic interference by the optimal delay coefficient and the optimal gain coefficient, when the vibration sensor is a seismometer, the calculation formula is:

where v _m (t) is the vibration velocity of the reference mirror; τ is the optimal delay coefficient; K is the optimal gain coefficient; U _s (t) is the output signal of the seismometer; v _s is the vibration velocity of the sensitive mass of the seismometer ; K _s is the nominal sensitivity of the seismometer;

When the vibration sensor is an accelerometer, the calculation formula is:

In the formula, v _m (t) is the vibration velocity of the reference mirror; τ is the optimal delay coefficient; K is the optimal gain coefficient; Ka is the nominal sensitivity of the accelerometer _{; U a (} t) is the output signal of the accelerometer .

Further, in the step S7, when calculating the vibration speed of the reference mirror during each atomic interference by the optimal delay coefficient and the optimal gain coefficient, when the vibration sensor is an accelerometer, the half-cycle integration algorithm is used to calculate the vibration of the reference mirror. speed.

Compared with the prior art, the present invention has the following advantages and positive effects:

The invention has excellent adaptability to the environment, it can achieve the best vibration compensation effect at the time and place when the measurement environment changes, and solves the problem that the vibration compensation effect of the existing vibration compensation method is relatively reduced when the measurement environment changes, The vibration compensation effect of the atomic gravimeter in the vibration environment is effectively improved, thereby improving the measurement accuracy of the atomic gravimeter, and further making a certain contribution to the measurement of absolute gravity.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

Fig. 1 is the flow chart of the vibration compensation method of Zhejiang University of Technology;

Figure 2 is a schematic diagram of atomic interference fringes;

Fig. 3 is the frame relationship diagram of the output signal of the seismometer and the real vibration of the reference mirror;

Fig. 4 is the vibration compensation algorithm flow chart of embodiment 1;

Fig. 5 is the vibration compensation algorithm flow chart of embodiment 2;

FIG. 6 is a flowchart of the vibration compensation algorithm of the tenth embodiment.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work, any modifications, equivalent replacements, improvements, etc., should be included in the protection scope of the present invention. Inside.

1. The general principle of vibration compensation for the interference fringes of the atomic interference gravimeter

The atomic gravimeter is based on the principle of cold atomic matter wave interference, which applies laser pulses to cold atomic groups, and realizes the atomic interference process through two-photon stimulated Raman transition or multi-photon Bragg diffraction process. Taking the atomic gravimeter based on stimulated Raman transition as an example, the cold atomic group falls freely in the vacuum cavity, and the plane reference mirror under the vacuum cavity reflects the vertically downward Raman laser in the same way, so that the two opposite laser beams are simultaneously Acting on the atomic group, in the process, three consecutive laser pulses realize the beam splitting, inversion and beam combining of the atomic wave packets, which are the first π/2 pulse, π pulse and the second π/2 pulse, respectively. The time interval between adjacent pulses is T. The atoms in any energy state after the beam combination are formed by the superposition of atoms on the two paths. The transition probability P of the atomic group after the pulse can be detected by the fluorescence signal, that is, the interference fringe, which satisfies

Among them, ΔФ is the atomic phase, which is related to the local gravitational acceleration g; the coefficients A and B representing the fringe contrast can be obtained by cosine fitting of the interference fringes. Ideally, the atomic phase ΔФ is equal to its theoretical value ΔФ _th , i.e.

ΔΦ _th =(k _eff g-α)T ² . (2)

Among them, k _eff is the effective wave vector, and α represents the frequency sweep rate of the laser. The control software of the gravimeter controls the linear increase of α in formula (2), then the atomic phase ΔФ will also change linearly, so that the interference fringes appear in the form of standard cosine signals. At this time, P should be exactly the same as the standard signal P _fit fitted by P, there are

But in practice, affected by various phase noises, the atomic phase ΔФ is equal to its actual value ΔФ _m , there are

Among them, _Δφvib is the phase noise introduced by the vibration of the reference mirror, hereinafter referred to as the vibration phase; Δφothers is the sum of the phase noises introduced by other noise sources, hereinafter referred to as the other phase noise. At this time, P changes from P _fit to

When the vibration phase is dominant in the phase noise, the vibration compensation process for correcting the interference fringes P can be determined according to the above principles.

The first step is to perform cosine fitting on the original measured fringe P(ΔФ _th ) (Note: the fringe is the curve, outside the brackets is the ordinate of the curve, and inside the brackets is the abscissa of the curve) to obtain the fitted theoretical fringe P _fit (ΔФ _th ) and coefficients A and B in equation (1).

In the second step, the real vibration velocity v _m of the reference mirror of the reference mirror within a period of time t is obtained through the vibration sensor, and then according to

Calculate the real vibration phase Δφ _vib , where S(t) is the sensitivity function of the gravimeter, T ₁ and T ₃ are the action moments of the first π/2 pulse and the second π/2 pulse, both determined by gravity It is determined by the known parameters of the instrument control software. It should also be noted that although the gravity value g is an unknown quantity to be measured, in the initial stage of the actual measurement, the approximate rough measured value g _th can be substituted into the formula (2) to calculate the theoretical atomic phase ΔФ _th to obtain the fitting fringe P. _fit , and then obtain the accurate measured value g through subsequent measurement and signal processing.

The third step is to calculate the atomic phase ΔФ _v and the transition probability P _v when only affected by vibration, namely

At this time, the data pair P(ΔФ _v ) obtained by taking ΔФ _v as the abscissa and P as the ordinate again is the corrected interference fringe, and the compensation process ends. As shown in Figure 2, compared with the original fringe P(ΔФ _th ), the abscissa of the corrected fringe P(ΔФ _v ) has shifted, and theoretically should be closer to the standard cosine signal, that is, the fitted theoretical fringe P _fit ( ΔФ _th ). That is to say, the goodness of fit when cosine fitting is performed on the modified stripe P(ΔФ _v ) again should be higher than that when the original stripe P(ΔФ _th ) is fitted.

2. The specific principle of the vibration compensation method described in the present invention

The method for simplifying the model based on the transfer function to realize the above vibration compensation process includes both hardware and software.

On the hardware side, a separate seismometer or accelerometer is used next to or below the reference mirror to measure its vibration. Taking the seismometer as an example, due to the limitation of the mechanical structure and the performance of the seismometer, the output signal U _s (t) of the seismometer cannot completely and truly reflect the vibration velocity v _m (t) of the reference mirror. The relationship between the two is shown in Figure 3. where _{Ga represents the transfer function from the ground vibration velocity to the reference mirror vibration velocity, G b represents} the transfer function from the ground vibration velocity to the vibration velocity of the sensitive mass of the seismometer, and G _c represents the velocity of the sensitive mass motion to the output of the seismometer transfer function between voltages. Since there must be horizontal and vertical differences between the sensitive mass inside the seismometer and the actual position of the reference mirror, G _a and G _b cannot be equal, and when the ground material changes, the two transfer functions themselves may also change.

On the other hand, the transfer function G _c of the seismometer itself is not an ideal transfer function with constant amplitude-frequency characteristics and linear phase-frequency characteristics, and may change with the change of measurement time and environment (this is because of temperature, humidity, air pressure, etc.). and other environmental parameters will affect the parameters of the electromechanical modules inside the seismometer, and these parameters may drift over time). To sum up, the transfer function H between the real vibration velocity of the reference mirror and the voltage signal output by the seismometer satisfies

Although G _a , G _b , and G _c are not easy to measure and may change in practice, so that the surveyor cannot obtain the exact value of the total transfer function H, the measurement environment will not change significantly in a single gravimetric measurement task, and the measurement time Generally it does not exceed 24 hours, so a simplified model consisting of a delay coefficient τ and a gain coefficient K can be used to estimate H, and it is considered that the values of these two coefficients remain unchanged during the current measurement process. From this, the simplified model of Figure 3 can be obtained as

where K _s is the nominal sensitivity of the seismometer, provided by the manufacturer.

Theoretically, when the delay coefficient τ and the gain coefficient K are the closest to the true value, the output voltage U _s of the seismometer and the vibration velocity _vm of the reference mirror calculated according to equation (9) are also closest to the true value, and the correction effect on the fringe most. Therefore, the specific idea of vibration compensation is: given the value range of τ and K, select a parameter representing the goodness of fit as the optimization target, and find the corresponding optimal delay coefficient τ when the parameter reaches the optimal value. _opt and the optimal gain coefficient K _opt . After the search is completed, when the delay is set as τ _opt and the gain as K _opt , the corrected stripe P(ΔФ _v ) is obtained, and the parameter value as the optimization target is recalculated.

In fact, the transfer function G _c of the seismometer itself is not an ideal form, that is, the amplitude-frequency characteristic is non-constant and the phase-frequency characteristic is nonlinear, so the output signal U _s (t) of the seismometer may be distorted. Therefore, before searching for the delay coefficient τ and the gain coefficient K, a correction filter F can be used to process the signal U _s (t) to reduce its distortion degree.

The hardware part is replaced by an accelerometer from a seismometer. The output signal U _a (t) of the accelerometer can be directly integrated once, and the reference mirror vibration signal v _m (t) can be obtained by combining the delay coefficient and gain coefficient.

The corresponding calculation formula is

Among them, Ka is the nominal sensitivity of the accelerometer, which is provided by the manufacturer _; the integration time is set according to actual needs, at least including the entire time period during which the atomic group is free to fall. The reference mirror velocity signal _vm (t) can also be calculated from the accelerometer signal U _a (t) using other integration algorithms such as half-cycle integration.

3. Examples

(1) Example 1

A vibration compensation method for correcting interference fringes of an atomic interference gravimeter, characterized in that it comprises the following steps:

S1. Given sweep rate sequence, gravity reference value, pulse interval duration, and effective wave vector;

S2. Import the measured transition probability sequence corresponding to the frequency sweep rate sequence, the vertical output signal of the vibration sensor measuring the vibration of the reference mirror in the same period, and the trigger signal before each atomic group falls in the same period;

S3. Calculate and set the RMSE value of the original stripe fitting as the optimization target through the original stripe;

S4, dividing the seismometer signal according to the trigger signal to obtain the seismometer signal corresponding to each transition probability;

S5, the starting range of the given delay coefficient and gain coefficient;

S6, obtain the optimal delay coefficient and the optimal gain coefficient through the traversal search method;

S7. Calculate the vibration speed of the reference mirror during each atomic interference through the optimal delay coefficient and optimal gain coefficient, and then obtain the vibration phase noise sequence, the atomic phase sequence only affected by vibration, and the correction fringes, and finally calculate the correction fringes. RMSE value when fitted to a standard cosine signal.

In this embodiment, the hardware sensor adopts a seismometer, and the output signal is Us ( _t ). Taking the RMSE value (Root Mean Square Error, root mean square error) when fitting stripes as the optimization goal, first traverse the search delay coefficient τ, and then traverse the search gain coefficient K. When the RMSE value reaches the minimum value, the corresponding delay coefficient and gain coefficient are respectively τ _opt and K _opt . The specific algorithm flow is shown in Figure 4.

(2) Example 2

The steps are the same as those in Embodiment 1, and the RMSE value when fitting the stripes is still used as the optimization target. In Embodiment 2, the golden section method is used to search for the delay coefficient τ and the gain coefficient K at the same time. The specific algorithm flow is shown in Figure 5.

(3) Embodiment 3

A correction step is added to the seismometer signal U _s (t) after "data preprocessing" in Fig. 4, that is, the signal is filtered with the set corrector transfer function F. The specific filter function can be written or used independently. The software's own function library. The procedures of "traversing search for optimal parameters" and "result calculation" in Embodiment 1 are then performed on the corrected signal.

(4) Embodiment 4

Taking the R-square (coefficient of determination) when fitting the stripes as the optimization objective, the delay coefficient and gain coefficient corresponding to the R-square value reaching the minimum value are taken as τ _opt and K _opt , respectively. The method for searching the delay coefficient search and the gain coefficient K is the same as that of Embodiment 1, that is, traversal search.

(5) Example 5

Taking the R-square (coefficient of determination) when fitting the stripes as the optimization objective, the delay coefficient and gain coefficient corresponding to the R-square value reaching the minimum value are taken as τ _opt and K _opt , respectively. The search delay coefficient and the search gain coefficient K are the same as those in Embodiment 2, that is, the golden section method is adopted.

(6) Embodiment 6

The RMSE value has a simple and intuitive mathematical meaning, but the physical meaning is not obvious. Therefore, another variable with more physical meaning can be used as the optimization target, that is, the change of the interference fringe fitting residual. The steps of searching for coefficients are the same as those in Embodiment 1, and are still traversing the search delay coefficient τ first, and then traversing the search gain coefficient K.

Before running the vibration compensation algorithm, first calculate the standard deviation σ _m of the residual R _m (ΔФ _th ) of the original fringe P (ΔФ _th ) compared to the theoretical fringe P _fit (ΔФ _th ). When running the vibration compensation algorithm, given the current delay coefficient τ, the residual R _v of the interference fringes P _v only affected by vibration compared to the theoretical fringes P _fit is obtained according to equations (6) (7) (9). Meanwhile, the difference between the original fringe P and the fringe P _v only affected by vibration is recorded as R _c . Obviously, R _c is the difference between the original fringe residual R _m and the fringe residual R _v only affected by vibration, which is equivalent to the fringe residual after removing the vibration effect. Theoretically, the better the vibration compensation effect is, the more accurate the calculation of the vibration phase _Δφvib will be, and the calculated fringe residual R _v only caused by vibration will be closer to the original fringe residual R _m . At this time, R _c will approach the fringe residual only introduced by other phase noises Δφ _others , and its standard deviation σ _c should also approach the minimum value. Therefore, in Embodiment 6, σ _c is set as the optimization target, and the corresponding delay coefficients and gain coefficients respectively when σ _c reaches the minimum value are τ _opt and K _opt ; That is, traverse searches separately.

(7) Example 7

Taking the interference fringe residual standard deviation σ _c in the embodiment 6 as the optimization target, the golden section method in the embodiment 2 is adopted, and the delay coefficient τ and the gain coefficient K are simultaneously searched.

(8) Example 8

As described in Example 6, theoretically, the better the vibration compensation effect is, the closer the calculated fringe residual R _v only caused by vibration is to the original fringe residual R _m . Therefore, Embodiment 8 takes the correlation coefficient CR of _{R m} and _{R v} as the optimization target, traverses and searches for the delay coefficient τ, and takes the corresponding delay coefficient when the absolute value of CR reaches the maximum value as τ _opt .

Since the original data needs to be normalized when calculating the correlation coefficient, _CR cannot be used as the optimization target when searching for the gain coefficient. Here, the RMSE value in Embodiment 1 can be used as the optimization target of traversing the search gain coefficient K.

(9) Example 9

Taking the correlation coefficient _CR in Embodiment 8 as the optimization target, the search delay coefficient τ is traversed. Then, the standard deviation σ _c of the interference fringe residuals in Example 6 is taken as the optimization target, and the gain coefficient K is traversed and searched.

(10) Example 10

The hardware sensor for vibration compensation is replaced by an accelerometer, and the output signal is U _a (t). At this time, the vibration velocity signal _vm (t) of the reference mirror can be obtained from U _a (t) by using one integration and combining the delay coefficient and the gain coefficient. Still the same steps as in Embodiment 1, take the RMSE value when fitting the fringes as the optimization target, and traverse the search delay coefficient τ and gain coefficient K respectively. The specific algorithm flow is shown in Figure 6.

(11) Example 11

The hardware sensor for vibration compensation is still an accelerometer, and the method for calculating the velocity signal v _m (t) from the acceleration signal U _a (t) in Embodiment 10 adopts the half-cycle integration method. Still taking the RMSE value when fitting the stripes as the optimization objective, traverse the search delay coefficient τ and gain coefficient K respectively.

The invention has excellent adaptability to the environment, it can achieve the best vibration compensation effect at the time and place when the measurement environment changes, and solves the problem that the vibration compensation effect of the existing vibration compensation method is relatively reduced when the measurement environment changes, The vibration compensation effect of the atomic gravimeter in the vibration environment is effectively improved, thereby improving the measurement accuracy of the atomic gravimeter, and further making a certain contribution to the measurement of absolute gravity.

Claims (7)

1. a vibration compensation method for revising atomic interference gravimeter interference fringes, is characterized in that: comprise the following steps: S1. Given sweep rate sequence, gravity reference value, pulse interval duration, and effective wave vector; S2. Import the measured data; S3. Calculate and set the optimization goal through the original stripe; S4. Divide the vibration sensor signal according to the trigger signal, and obtain the vibration sensor signal corresponding to each transition probability; S5, the starting range of the given delay coefficient and gain coefficient; S6. Obtain the optimal delay coefficient and the optimal gain coefficient through the traversal search method or the golden section search method; S7. Calculate the vibration speed of the reference mirror during each atomic interference through the optimal delay coefficient and optimal gain coefficient, and then obtain the vibration phase noise sequence, the atomic phase sequence only affected by vibration, and the correction fringes, and finally calculate the correction fringes. RMSE value when fitted to a standard cosine signal. 2. the vibration compensation method for correcting the interference fringes of the atomic interference gravimeter as claimed in claim 1, is characterized in that: in the described step S2, the measured data comprises the measured transition probability sequence corresponding to the frequency sweep rate sequence, the same time period The vibration sensor that measures the vibration of the reference mirror in the vertical direction outputs a signal and a trigger signal before each atomic group falls in the same period. 3. the vibration compensation method that is used to correct the interference fringes of atomic interference gravimeter as claimed in claim 2, it is characterized in that: in described step S3, optimization target is the RMSE value when original fringe fitting, during original fringe fitting One of the coefficient of determination of , the standard deviation of the interference fringe residual, and the correlation coefficient between the original fringe residual and the fringe residual only affected by vibration. 4 . The vibration compensation method for correcting interference fringes of an atomic interference gravimeter according to claim 1 , wherein in the step S4 , a filter processing operation is performed on the vibration sensor signal with a corrector transfer function. 5 . 5. the vibration compensation method for correcting the interference fringes of atomic interference gravimeter as claimed in claim 3, is characterized in that: in described step S6, use traversal search method or golden section search method to obtain optimal delay coefficient, When the optimal gain coefficient is used, when the optimization target is the RMSE value of the original fringe fitting, the delay coefficient and gain coefficient corresponding to the RMSE value of the original fringe fitting reaching the minimum value are used as the optimal delay coefficient and the optimal gain coefficient. gain factor; When the optimization target is the coefficient of determination in the original fringe fitting, the delay coefficient and gain coefficient corresponding to when the coefficient of determination in the original fringe fitting reaches the minimum value are used as the optimal delay coefficient and optimal gain coefficient; When the optimization target is the standard deviation of the interference fringe residual, the delay coefficient and gain coefficient corresponding to when the standard deviation of the interference fringe residual reaches the minimum value are taken as the optimal delay coefficient and optimal gain coefficient; When the optimization objective is the correlation coefficient between the original fringe residual and the fringe residual only affected by vibration, the absolute value of the correlation coefficient between the original fringe residual and the fringe residual only affected by vibration reaches the maximum value The corresponding delay coefficient is used as the optimal delay coefficient; the corresponding gain coefficient when other optimization targets reach the minimum value is used as the optimal gain coefficient. 6. The vibration compensation method for correcting the interference fringes of an atomic interference gravimeter as claimed in claim 5, wherein in the step S7, each time the atomic interference is calculated by the optimal delay coefficient and the optimal gain coefficient When the reference mirror vibration velocity is , when the vibration sensor is seismic timing, the calculation formula is:

where v _m (t) is the vibration velocity of the reference mirror; τ is the optimal delay coefficient; K is the optimal gain coefficient; U _s (t) is the output signal of the seismometer; v _s is the vibration velocity of the sensitive mass of the seismometer ; K _s is the nominal sensitivity of the seismometer; When the vibration sensor is an accelerometer, the calculation formula is:

In the formula, v _m (t) is the vibration velocity of the reference mirror; τ is the optimal delay coefficient; K is the optimal gain coefficient; Ka is the nominal sensitivity of the accelerometer _{; U a (} t) is the output signal of the accelerometer . 7. The vibration compensation method for correcting the interference fringes of an atomic interference gravimeter as claimed in claim 5, wherein in the step S7, each time the atomic interference is calculated by the optimal delay coefficient and the optimal gain coefficient When the vibration velocity of the reference mirror is , when the vibration sensor is an accelerometer, the half-cycle integration algorithm is used to calculate the vibration velocity of the reference mirror.

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