Co-seismic static inclination measurement method and device based on triaxial accelerometer, medium, computer program product and application

Abstract

The invention relates to the technical field of earthquake rotating field observation, in particular to a co-earthquake static inclination measurement method and device based on a triaxial accelerometer, a medium, a computer program product and application, and the method comprises the following steps: collecting original acceleration data in real time by adopting the triaxial accelerometer of a strong earthquake station; calculating the gravitational acceleration at the strong earthquake station according to the locally stored position coordinates of the strong earthquake station; calculating a corrected acceleration sequence at the strong shock station according to the original acceleration data and the gravitational acceleration; and according to the corrected acceleration sequence and the gravitational acceleration, calculating the co-seismic static inclination amount at the strong-seismic station. According to the method, the co-earthquake static inclined field can be rapidly measured by using the existing strong earthquake observation network according to the relationship of the three-component projection of the gravitational acceleration before and after the earthquake.

Description

Technical Field

[0001] The present invention relates to the technical field of earthquake rotation field observation, and in particular to a co-seismic static tilt measurement method, equipment, medium, computer program product and application based on a three-axis accelerometer. Background Art

[0002] The complete motion state description of the earthquake deformation body includes six-component strain, three-component translation (displacement, velocity and acceleration) and three-component rotation (torsion and tilt). At present, the co-seismic translation measurement technology is relatively mature, and the earthquake translation field can be measured by various methods, such as seismic inertial measurement instruments (broadband seismometers and strong earthquake instruments), global navigation satellite systems (GNSS) and synthetic aperture radar interferometry (InSAR). However, the earthquake rotation has long been considered meaningless and difficult to observe, so it is often ignored by researchers. Until recently, seismologists have gradually realized the importance of co-seismic rotation to seismological research. For example, relevant studies have shown that the earthquake rotation observed in the near field is 1 to 2 orders of magnitude larger than the amount derived from classical elastic theory. This error is the fundamental reason why it is difficult to accurately reconstruct the co-seismic displacement signal from the near-field strong earthquake acceleration data.

[0003] Unfortunately, it is still difficult to accurately record the coseismic rotation. Inertial gyroscopes can measure angular velocity with high precision, but the seismological community cannot afford to widely deploy these expensive instruments. Some scholars have proposed using dense arrays of seismic stations to indirectly measure the coseismic rotation of earthquakes. However, the seismic station array can only measure the dynamic rotation of earthquakes, and this dynamic rotation is the "average" of the rotation in a specific area. In addition, some scholars have proposed to restore the coseismic rotation of ground points by combining high-frequency GPS and three-axis accelerometers. However, this seismic geodetic method may have the following three problems. First, the state equation of the Kalman filter is inaccurate. The near-field area of ​​a large earthquake usually experiences violent vibrations. In such a high-dynamic environment, the uniform acceleration model may also have errors. Second, the observation equation of the Kalman filter is also inaccurate. The observation equation is simplified twice: first, the observation equation is linearized by small angle approximation; second, the rank deficiency problem of the linearized observation equation is solved by introducing pseudotilts to replace the tilt and torsion parameters. Finally, the seismic geodetic method relies on high-frequency GPS and accelerometer co-location data. In the near-field of a large earthquake, the seismic waveforms recorded by two observation stations with a small station spacing are likely to be very different. Strict high-frequency GPS and accelerometer co-location stations (station spacing is zero) are usually uncommon. Summary of the invention

[0004] Since the ground near the earthquake often undergoes permanent rotation, the coordinate axis orientation of the three-axis accelerometer fixed to the ground is usually different before and after the earthquake, which causes the three-component projection of gravity acceleration on the three-axis accelerometer to change before and after the earthquake. The present invention discloses a co-seismic static tilt measurement method, device, medium, computer program product and application based on a three-axis accelerometer to solve the defects of the prior art.

[0005] A first aspect of the present invention provides a co-seismic static tilt measurement method based on a triaxial accelerometer, which uses only triaxial accelerometer data to quickly determine the co-seismic static tilt of a ground point, comprising the following steps:

[0006] The three-axis accelerometer of the strong earthquake station is used to collect raw acceleration data in real time;

[0007] Calculating the gravitational acceleration at the strong earthquake station according to the position coordinates of the strong earthquake station stored locally;

[0008] Calculating a corrected acceleration sequence at the strong earthquake station according to the original acceleration data and the gravitational acceleration;

[0009] The co-seismic static tilt at the strong earthquake station is calculated based on the corrected acceleration sequence and the gravitational acceleration.

[0010] Preferably, the coordinate axis orientation of the three-axis accelerometer is corrected before the earthquake so that the coordinate axis orientation of the three-axis accelerometer before the earthquake is consistent with the coordinate axis orientation of the station center coordinate system at the strong earthquake station.

[0011] Preferably, the step of calculating the corrected acceleration sequence at the strong earthquake station according to the original acceleration data and the gravitational acceleration comprises the following steps:

[0012] Detecting the arrival time of the P wave at the strong earthquake station according to the original acceleration data;

[0013] Calculating a constant deviation of a triaxial accelerometer at the strong earthquake station according to the raw acceleration data, the P wave arrival time and the gravitational acceleration;

[0014] A corrected acceleration sequence at the strong earthquake station is calculated based on the original acceleration data and the constant deviation.

[0015] Preferably, the long-short time averaging method is used to detect the arrival time of the P wave at the strong earthquake station.

[0016] Preferably, the calculating the co-seismic static tilt at the strong earthquake station according to the corrected acceleration sequence and the gravitational acceleration comprises the following steps:

[0017] Constructing a projection vector of the three components of the gravitational acceleration before the earthquake according to the gravitational acceleration;

[0018] Determining the moment when the vibration of the strong earthquake station tends to be stable according to the modified acceleration sequence;

[0019] Constructing a three-component projection vector of gravity acceleration after the earthquake according to the modified acceleration sequence and the moment when the vibration tends to be stable;

[0020] The co-seismic static tilt at the strong earthquake station is calculated according to the projection vector of the three components of gravity acceleration before the earthquake and the projection vector of the three components of gravity acceleration after the earthquake.

[0021] Preferably, the moment when the vibration of the strong earthquake station tends to stabilize is determined by using an empirical threshold method based on the modified acceleration sequence.

[0022] A second aspect of the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the co-seismic static tilt measurement method based on a three-axis accelerometer when executing the program.

[0023] A third aspect of the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the co-seismic static tilt measurement method based on a three-axis accelerometer.

[0024] A fourth aspect of the present invention provides a computer program product, comprising a computer program, which, when executed by a processor, implements the co-seismic static tilt measurement method based on a three-axis accelerometer.

[0025] The fifth aspect of the present invention provides an application of a co-seismic static tilt measurement method based on a three-axis accelerometer, and the co-seismic static tilt measured by this method is sent to an earthquake early warning center to provide accurate static rotation field information for applications such as rotational seismology research and earthquake early warning.

[0026] The present invention has the following advantages and beneficial effects:

[0027] The present invention can use the existing strong earthquake observation network to quickly determine the co-seismic static tilt field based on the relationship between the three-component projections of gravity acceleration before and after the earthquake. Compared with the traditional co-seismic rotation measurement method, the method of the present invention has richer data sources, does not rely on expensive gyroscopes, and is not limited to rare high-frequency GPS / accelerometer co-location stations.

[0028] The method of the present invention can obtain the rotation amount of the ground point instead of the rotation "average value". The solution of the present invention is simple and convenient to implement, and has strong practicality and universality. It solves the problems of low practicality and inconvenience in practical application of related technologies, can improve user experience, and has important market value. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a flowchart of a co-seismic static tilt measurement method based on a three-axis accelerometer according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The technical scheme of the present invention is specifically described below in conjunction with the accompanying drawings and embodiments. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0031] Those skilled in the art will appreciate that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined.

[0032] Since the ground near the earthquake often undergoes permanent rotation, the coordinate axis orientation of the three-axis accelerometer fixed to the ground is usually different before and after the earthquake, which causes the three-component projection of gravity acceleration on the three-axis accelerometer to change before and after the earthquake. The present invention discloses a co-seismic static tilt measurement method based on a three-axis accelerometer. The present invention uses the relationship between the three-component projections of gravity acceleration before and after the earthquake to quickly determine the co-seismic static tilt of a large earthquake, in order to provide accurate static rotation field information for applications such as rotational seismology research and earthquake early warning.

[0033] Figure 1 A flowchart of a co-seismic static tilt measurement method based on a triaxial accelerometer is provided in this embodiment, and the specific steps are as follows:

[0034] S11, the three-axis accelerometer of the strong earthquake station collects raw acceleration data in real time, and sends the collected raw acceleration data to the ground computing center;

[0035] S12, the ground computing center calculates the gravity acceleration at the strong earthquake station according to the position coordinates of the strong earthquake station stored locally;

[0036] S13, the ground computing center calculates a corrected acceleration sequence at the strong earthquake station according to the original acceleration data and the gravitational acceleration;

[0037] S14, the ground computing center calculates the co-seismic static tilt at the strong earthquake station according to the corrected acceleration sequence and the gravitational acceleration;

[0038] S15. The ground computing center sends the co-seismic static tilt to an earthquake early warning center, etc., in order to provide accurate static rotation field information for applications such as rotational seismology research and earthquake early warning.

[0039] Further, in S12, the ground computing center calculates the gravity acceleration at the strong earthquake station according to the position coordinates of the strong earthquake station stored locally, and the specific formula is as follows:

[0040]

[0041] In the formula, and h are the latitude and geodetic height of the strong earthquake station, respectively; a and b are the lengths of the major and minor axes of the Earth reference ellipsoid, respectively; f is the flattening of the Earth reference ellipsoid; ω e is the angular velocity of the Earth's rotation; GM is the Earth's gravitational constant; r a and r b are the gravitational acceleration at the equator and the poles, respectively; is the gravitational acceleration at a point near the Earth.

[0042] For the GRS80 reference ellipsoid

[0043]

[0044] Further, in S13, the ground computing center calculates the corrected acceleration sequence at the strong earthquake station according to the original acceleration data and the gravitational acceleration, which is achieved through the following specific process:

[0045] Step 1: The ground computing center detects the arrival time of the P wave of the strong earthquake station based on the original acceleration data using the long-short time average method (STA / LTA);

[0046] Step 2: The ground computing center calculates the constant deviation of the triaxial accelerometer at the strong earthquake station according to the original acceleration data, the P wave arrival time and the gravity acceleration. The specific formula is as follows:

[0047]

[0048] Wherein, e, n and u represent east-west, north-south and vertical directions respectively; b is the constant deviation of the accelerometer; A is the original acceleration data; t p is the arrival time of the P wave at the strong earthquake station; g is the gravitational acceleration of the strong earthquake station.

[0049] Step 3: The ground computing center calculates the corrected acceleration sequence at the strong earthquake station based on the original acceleration data and the constant deviation. The specific formula is as follows:

[0050]

[0051] Where, t k represents the k moment; α is the corrected acceleration at the strong earthquake station. More specifically, and are the original accelerations of the east-west axis, north-south axis, and vertical axis of the three-axis accelerometer at the strong earthquake station at time k respectively; and are respectively the corrected accelerations of the east-west axis, north-south axis, and vertical axis of the three-axis accelerometer at the strong earthquake station at time k.

[0052] Furthermore, in S14, the ground computing center calculates the co-seismic static tilt at the strong earthquake station according to the corrected acceleration sequence and the gravitational acceleration, which is achieved through the following specific process:

[0053] Step 1: The ground computing center constructs the three-component projection vector of the gravity acceleration before the earthquake based on the gravity acceleration, which can be specifically:

[0054] g pre =[0, 0, g] Τ (5)

[0055] In the formula, g pre is the projection vector of the three components of gravitational acceleration before the earthquake; [*] Τ It is worth noting that the method of the present invention needs to calibrate the coordinate axis orientation of the triaxial accelerometer before the earthquake to ensure that the coordinate axis orientation of the triaxial accelerometer before the earthquake is consistent with the coordinate axis orientation of the station center coordinate system at the strong earthquake station.

[0056] Step 2: The ground computing center determines the moment when the "vibration tends to be stable" of the strong earthquake station based on the modified acceleration sequence and using the empirical threshold method;

[0057] Step 3: The ground computing center constructs the three-component projection vector of gravity acceleration after the earthquake based on the modified acceleration sequence and the moment when the vibration tends to be stable. Specifically, it can be:

[0058]

[0059] In the formula, g pos is the projection vector of the three components of gravity acceleration after the earthquake, t s is the moment when the vibration of the strong earthquake station becomes stable. and are the t of the east-west axis, north-south axis, and vertical axis of the three-axis accelerometer at the strong earthquake station. s Corrected acceleration.

[0060] Step 4: The ground computing center calculates the co-seismic static tilt at the strong earthquake station according to the projection vector of the three components of gravity acceleration before the earthquake and the projection vector of the three components of gravity acceleration after the earthquake. The specific formula is as follows:

[0061]

[0062] In the formula, ψ, θ and φ are heading angle, pitch angle and roll angle respectively; c* and s* represent cos(*) and sin(*) respectively. Taking into account equations (5) and (6), we can get

[0063]

[0064] Wherein, t* represents tan(*). When implementing the program, φ should be calculated first, and then θ. It is worth noting that ψ has infinite solutions, so the method of the present invention cannot uniquely determine the torsion angle, but can only determine the static tilt amount.

[0065] A second aspect of the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the co-seismic static tilt measurement method based on a three-axis accelerometer when executing the program.

[0066] A third aspect of the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the co-seismic static tilt measurement method based on a three-axis accelerometer.

[0067] A fourth aspect of the present invention provides a computer program product, comprising a computer program, which, when executed by a processor, implements the co-seismic static tilt measurement method based on a three-axis accelerometer.

[0068] The fifth aspect of the present invention provides an application of a co-seismic static tilt measurement method based on a three-axis accelerometer, and the co-seismic static tilt measured by this method is sent to an earthquake early warning center to provide accurate static rotation field information for applications such as rotational seismology research and earthquake early warning.

[0069] For the method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the embodiments of the present invention are not limited by the order of the actions described, because according to the embodiments of the present invention, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily required by the embodiments of the present invention.

[0070] In specific implementation, the method proposed in the technical solution of the present invention can be implemented by technical personnel in this field using computer software technology to realize automatic operation process. System devices for implementing the method, such as computer-readable storage media storing the corresponding computer program of the technical solution of the present invention and computer equipment running the corresponding computer program, should also be within the scope of protection of the present invention.

[0071] The above is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and changes can be made without departing from the principle of the present invention, and these improvements and changes are also regarded as the protection scope of the present invention.

Claims

1. A co-seismic static tilt measurement method based on a triaxial accelerometer, characterized in that: The rapid determination of the co-seismic static tilt of a ground point using only triaxial accelerometer data includes the following steps: The three-axis accelerometer of the strong earthquake station is used to collect raw acceleration data in real time; Calculating the gravitational acceleration at the strong earthquake station according to the position coordinates of the strong earthquake station stored locally; Calculating a corrected acceleration sequence at the strong earthquake station according to the original acceleration data and the gravitational acceleration; The co-seismic static tilt at the strong earthquake station is calculated based on the corrected acceleration sequence and the gravitational acceleration.

2. The co-seismic static tilt measurement method based on a triaxial accelerometer according to claim 1, characterized in that: Before the earthquake, the coordinate axis orientation of the three-axis accelerometer is corrected so that the coordinate axis orientation of the three-axis accelerometer before the earthquake is consistent with the coordinate axis orientation of the station center coordinate system at the strong earthquake station.

3. The co-seismic static tilt measurement method based on a triaxial accelerometer according to claim 1, characterized in that: The step of calculating the modified acceleration sequence at the strong earthquake station according to the original acceleration data and the gravitational acceleration comprises the following steps: Detecting the arrival time of the P wave at the strong earthquake station according to the original acceleration data; Calculating a constant deviation of a triaxial accelerometer at the strong earthquake station according to the raw acceleration data, the P wave arrival time and the gravitational acceleration; A corrected acceleration sequence at the strong earthquake station is calculated based on the original acceleration data and the constant deviation.

4. The co-seismic static tilt measurement method based on a triaxial accelerometer according to claim 3, characterized in that: The long-short time averaging method is used to detect the P wave arrival time of the strong earthquake station.

5. The co-seismic static tilt measurement method based on a triaxial accelerometer according to claim 1, characterized in that: The step of calculating the co-seismic static tilt at the strong earthquake station according to the corrected acceleration sequence and the gravitational acceleration comprises the following steps: Constructing a projection vector of the three components of the gravitational acceleration before the earthquake according to the gravitational acceleration; Determining the moment when the vibration of the strong earthquake station tends to be stable according to the modified acceleration sequence; Constructing a three-component projection vector of gravity acceleration after the earthquake according to the modified acceleration sequence and the moment when the vibration tends to be stable; The co-seismic static tilt at the strong earthquake station is calculated according to the projection vector of the three components of gravity acceleration before the earthquake and the projection vector of the three components of gravity acceleration after the earthquake.

6. The co-seismic static tilt measurement method based on a triaxial accelerometer according to claim 5, characterized in that: The time when the vibration of the strong earthquake station tends to be stable is determined by using the empirical threshold method according to the modified acceleration sequence.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the co-seismic static tilt measurement method based on a three-axis accelerometer as described in any one of claims 1-6 is implemented.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the co-seismic static tilt measurement method based on a three-axis accelerometer as described in any one of claims 1 to 6 is implemented.

9. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the co-seismic static tilt measurement method based on a three-axis accelerometer as described in any one of claims 1 to 6 is implemented.

10. An application of a co-seismic static tilt measurement method based on a triaxial accelerometer, characterized in that: The co-seismic static tilt measured by this method will be sent to the earthquake early warning center to provide accurate static rotation field information for applications such as rotational seismology research and earthquake early warning.

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