Ground-based radar atmospheric parameter correction method based on meteorological parameter correction

Abstract

The invention discloses a ground-based radar atmospheric parameter correction method based on meteorological parameter correction, and the method comprises the steps: determining a reference point according to the distance bin of a ground-based radar, obtaining the temperature of a mercurial thermometer of the reference point and the data of an electronic meteorological instrument, building a temperature correction model, calculating a first atmospheric phase according to the electronic meteorological data, and determining a stable reference point, obtaining the correction temperature of the stable reference point through the temperature correction model, building a relative humidity correction model according to the correction temperature, obtaining the correction relative humidity, carrying out the atmospheric compensation according to the correction temperature and the correction relative humidity, and determining the micro-deformation of the target point according to the atmospheric compensation result. The method not only can improve the precision of the ground-based radar atmospheric parameter correction method and obtain high-precision and credible micro-deformation data, but also has good interpretability, and is of great significance to health assessment of building structures.

Description

Technical Field

[0001] The invention relates to the field of parameter correction, and in particular to a method for correcting atmospheric parameters of a ground-based radar based on meteorological parameter correction. Background Art

[0002] Ground-based radar has the advantages of non-contact, high precision, high sampling frequency and overall dynamic monitoring. The system can observe the movement of actively deformed bodies in real time, effectively solving the shortcomings of traditional deformation monitoring technology in terms of measurement range, monitoring distance, accuracy and environmental adaptability. With the continuous development of ground-based radar in deformation monitoring work, its accuracy continues to improve. When the atmospheric environment remains almost unchanged, the observation accuracy reaches the sub-millimeter level.

[0003] However, in the actual environment, the atmospheric environment is changeable. During the propagation of electromagnetic waves in the atmosphere, the atmospheric medium will refract the propagation direction, causing propagation time delay and propagation path bending problems, thereby generating atmospheric phase errors, causing radar measurement errors to reach the centimeter level, seriously affecting the accuracy of deformation monitoring results. Therefore, atmospheric correction is a necessary step to ensure monitoring accuracy.

[0004] The present invention uses the temperature data collected by a mercury thermometer as a benchmark, corrects the data collected by an electronic meteorological instrument, establishes a temperature correction model, uses the meteorological data of a stable reference point in the monitoring field of view to establish a relative humidity correction model, and finally uses the corrected temperature and relative humidity data to perform atmospheric compensation and calculate the micro-deformation of the ground-based radar target point. An atmospheric parameter correction method for a ground-based radar based on meteorological parameter correction is proposed to overcome the shortcomings of the existing optimization and adjustment methods. This method can significantly improve the accuracy of the atmospheric parameter correction method, thereby improving the credibility of the data collected by the ground-based radar and achieving long-term evaluation of the health of the building structure. Summary of the invention

[0005] The object of the present invention is to provide a method for correcting atmospheric parameters of a ground-based radar based on meteorological parameter correction.

[0006] To achieve the above object, the present invention is implemented according to the following technical solutions:

[0007] The present invention comprises the following steps:

[0008] Determine a reference point according to the distance bin of the ground-based radar, and obtain the mercury thermometer temperature and electronic meteorological data of the reference point; the electronic meteorological data includes the electronic meteorological instrument temperature, relative humidity and atmospheric pressure;

[0009] Constructing a temperature correction model according to the mercury thermometer temperature and the electronic meteorological instrument data;

[0010] Calculate the first atmospheric phase based on the electronic meteorological data, determine the stable reference point according to the first atmospheric phase, and input the temperature of the electronic meteorological instrument at the stable reference point into the temperature correction model to obtain the corrected temperature;

[0011] Construct a relative humidity correction model based on the corrected temperature, and input the relative humidity at the stable reference point into the relative humidity correction model to obtain the corrected relative humidity;

[0012] Perform atmospheric compensation based on the corrected temperature and the corrected relative humidity, and determine the micro-deformation of the target point according to the atmospheric compensation result.

[0013] Further, the method for constructing the temperature correction model includes:

[0014] Set a thermal signal-to-noise ratio threshold to screen the reflection points to obtain reference points, and obtain the mercury thermometer temperature and electronic meteorological data of the reference points;

[0015] Divide the temperature data into a training set and a test set; the temperature data is specifically the mercury thermometer temperature T i y and the electronic meteorological instrument temperature T i x , where i = 1, 2, …, n, and n is the number of collected temperatures;

[0016] Determine the order m of the temperature correction model according to the Bayesian information criterion, where m < n, and construct an m + 1 order temperature correction model, the expression of which is:

[0017] f(T i x ) = α0 + α1T i x + α2(T i x ) 2 + … + α m (T i x ) m

[0018] where f(T i x ) is the corrected temperature when the electronic meteorological instrument temperature is T i x , and α i ∈{α0, α1, α2, …, α m} are the temperature correction model coefficients;

[0019] Determine the optimization objective function AIM1 of the temperature correction model coefficients, the expression of which is:

[0020]

[0021] Input the training set data into the objective function AIM1 to fit the temperature correction model coefficient α i When the objective function AIM1 is minimum, the corresponding temperature correction model coefficient α is output i , using α i Update the temperature correction model, use the test set data to verify the temperature correction model, and output the temperature correction model.

[0022] Furthermore, the method for determining the stable reference point includes:

[0023] The first atmospheric phase is calculated based on the reference point electronic meteorological data, and the expression is:

[0024]

[0025] in is the first atmospheric phase, λ is the wavelength of the electromagnetic wave emitted by the ground-based radar, r is the monitoring distance of the target point from the radar, N is the atmospheric refractive index in the monitoring environment at time t, T t x is the temperature of the electronic meteorological instrument at time t, P t is the atmospheric pressure at time t, RH t is the relative humidity at time t;

[0026] The reference point is screened twice according to the first atmospheric phase to obtain a stable reference point. The screening conditions are:

[0027]

[0028] in is the ground-based radar acquisition phase at time t The corresponding interference phase, S is an unbiased estimator.

[0029] Further, the method for obtaining the corrected relative humidity includes:

[0030] Determine the relative humidity correction model, the expression is:

[0031] g(RH t )=β0+β1RH t +β2(RH t ) 2

[0032] Where g(RH t ) is the relative humidity at time t, RH t Corrected relative humidity at , β0, β1, β2 are relative humidity correction model coefficients;

[0033] The second atmospheric phase is calculated based on the corrected temperature, corrected relative humidity and atmospheric pressure. The expression is:

[0034]

[0035] in is the second atmospheric phase, is the atmospheric pressure P at time t t and the corrected temperature f(T t ) calculated atmospheric phase, is the corrected relative humidity at time t g(RH t ) calculated atmospheric phase;

[0036] Determine the relative humidity correction model coefficient optimization objective function AIM2, the expression is:

[0037]

[0038] The relative humidity correction model coefficients are continuously optimized and adjusted. When the objective function AIM2 is minimized, the corresponding relative humidity correction model coefficients are output. The relative humidity correction model coefficients are used to update and output the relative humidity correction model. The relative humidity of the stable reference point is input into the relative humidity correction model to obtain the corrected relative humidity.

[0039] Furthermore, the method for determining the micro-deformation of the target point includes:

[0040] Calculate the second atmospheric phase based on the corrected temperature, corrected relative humidity and atmospheric pressure Perform atmospheric compensation and calculate the micro deformation of the ground-based radar target point based on the atmospheric compensation result:

[0041]

[0042] in is the differential phase after atmospheric compensation, is the ground-based radar acquisition phase at time t The corresponding interference phase, Δd is the micro-deformation of the ground-based radar target point, and λ is the wavelength of the electromagnetic wave emitted by the ground-based radar.

[0043] The beneficial effects of the present invention are:

[0044] The present invention is a method for correcting atmospheric parameters of ground-based radar based on meteorological parameter correction. Compared with the prior art, the present invention has the following technical effects:

[0045] The present invention can improve the accuracy of atmospheric parameter correction of ground-based radar by determining reference points, temperature correction, screening stable reference points, relative humidity correction and atmospheric compensation steps, thereby improving the atmospheric parameter correction speed of ground-based radar, can greatly save resources, improve the efficiency of atmospheric parameter correction, can effectively reduce the measurement error of electronic thermometers, improve the accuracy of temperature and relative humidity, ensure the reliability and accuracy of humidity data, and effectively perform atmospheric compensation on the data of target points, thereby obtaining high-precision and reliable micro-deformation data, which is of great significance for non-contact health monitoring of building structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 The present invention is a flow chart of the steps of the atmospheric parameter correction method for ground-based radar based on meteorological parameter correction. DETAILED DESCRIPTION

[0047] The present invention is further described below by means of specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0048] The present invention provides a method for correcting atmospheric parameters of ground-based radar based on meteorological parameter correction, comprising the following steps:

[0049] like Figure 1 As shown, in this embodiment, the following steps are included:

[0050] Determine a reference point according to the distance bin of the ground-based radar, and obtain the mercury thermometer temperature and electronic meteorological data of the reference point; the electronic meteorological data includes the electronic meteorological instrument temperature, relative humidity and atmospheric pressure;

[0051] Constructing a temperature correction model according to the mercury thermometer temperature and the electronic meteorological instrument data;

[0052] Calculate a first atmospheric phase according to the electronic meteorological data, determine a stable reference point according to the first atmospheric phase, and input the electronic meteorological instrument temperature of the stable reference point into the temperature correction model to obtain a corrected temperature;

[0053] Constructing a relative humidity correction model according to the corrected temperature, and inputting the relative humidity of the stable reference point into the relative humidity correction model to obtain a corrected relative humidity;

[0054] Atmospheric compensation is performed according to the corrected temperature and the corrected relative humidity, and the target point micro-deformation is determined according to the atmospheric compensation result.

[0055] In this embodiment, the method for constructing the temperature correction model includes:

[0056] Set the thermal signal-to-noise ratio threshold to screen the reflection points to obtain reference points, and obtain the mercury thermometer temperature and electronic meteorological data of the reference points;

[0057] Divide the temperature data into a training set and a test set; the temperature data is specifically the mercury thermometer temperature T i y and the electronic meteorological instrument temperature T i x , i = 1, 2, …, n, where n is the number of collected temperatures;

[0058] Determine the order m of the temperature correction model according to the Bayesian information criterion, where m < n, and construct an m + 1-order temperature correction model. The expression is:

[0059] f(T i x ) = α0 + α1T i x + α2(T i x ) 2 + … + α m (T i x ) m

[0060] where f(T i x ) is the corrected temperature when the electronic meteorological instrument temperature is T i x , and α i ∈{α0, α1, α2, …, α m} is the temperature correction model coefficient;

[0061] Determine the optimization objective function AIM1 of the temperature correction model coefficient. The expression is:

[0062]

[0063] Input the training set data into the objective function AIM1 to fit the temperature correction model coefficient α i , and output the corresponding temperature correction model coefficient α i when the objective function AIM1 is the smallest. Then use α i to update the temperature correction model, and use the test set data to verify the temperature correction model and output the temperature correction model;

[0064] In the actual assessment, taking the deformation monitoring of building structures in a certain area as an example, the reflection points with a thermal signal-to-noise ratio greater than 30dB were selected as reference points, and 10 reference points were screened to obtain the mercury thermometer temperature and electronic meteorological data of the reference points at a certain time (mercury thermometer temperature / ℃, electronic meteorological instrument temperature / ℃, relative humidity / %, atmospheric pressure / hPa): (20.1, 20.5, 40, 1010), (20.3, 20.6, 42, 1008), (2 0.2,20.4,41,1009),(20.4,20.7,43,1011),(20.0,20.4,40,1010),(20.3,20.5,42,1009),(20.2,20.4,40,1010),(20.4,20.6,43,1012),(20.1,20.4,38,1008),(20.3,20.5,41,1011);

[0065] According to the Bayesian information criterion, the order of the temperature correction model is determined to be 2, and a third-order temperature correction model is constructed. The optimized coefficients α0=0.2, α1=0.9, and α2=0.005 are obtained by training with the collected data.

[0066] In this embodiment, the method for determining the stable reference point includes:

[0067] The first atmospheric phase is calculated based on the reference point electronic meteorological data, and the expression is:

[0068]

[0069] in is the first atmospheric phase, λ is the wavelength of the electromagnetic wave emitted by the ground-based radar, r is the monitoring distance of the target point from the radar, N is the atmospheric refractive index in the monitoring environment at time t, T t x is the temperature of the electronic meteorological instrument at time t, P t is the atmospheric pressure at time t, RH t is the relative humidity at time t;

[0070] The reference point is screened twice according to the first atmospheric phase to obtain a stable reference point. The screening conditions are:

[0071]

[0072] in is the ground-based radar acquisition phase at time t The corresponding interference phase, S is an unbiased estimator;

[0073] In the actual evaluation, the monitoring distance of the ground-based radar is 100m, the wavelength of the electromagnetic wave emitted by the radar is 0.1m, and the first atmospheric phases of the 10 reference points are calculated based on the electronic meteorological data of the reference points: 6283.2, 6350.1, 6300.5, 6400.3, 6250.2, 6320.6, 6280.4, 6450.7, 6230.8, 6380.5 (unit: radian). The ground-based radar acquisition phases of the 10 reference points are: The corresponding interference phases are 6283.3, 6350.7, 6300.7, 6401.2, 6250.4, 6321.4, 6280.7, 6451.3, 6231.6, and 6381.7 (unit: radians). The thermal signal-to-noise ratio of the reference point is greater than 30 dB, i.e., the high signal-to-noise ratio condition is met. The unbiased estimator is 0.2 rad. The reference points are screened secondary according to the first atmospheric phase to determine the 1st, 3rd, 5th, and 7th reference points as stable reference points.

[0074] In this embodiment, the method for obtaining the corrected relative humidity includes:

[0075] Determine the relative humidity correction model, the expression is:

[0076] g(RH t )=β0+β1RH t +β2(RH t ) 2

[0077] Where g(RH t ) is the relative humidity at time t, RH t Corrected relative humidity at , β0, β1, β2 are relative humidity correction model coefficients;

[0078] The second atmospheric phase is calculated based on the corrected temperature, corrected relative humidity and atmospheric pressure. The expression is:

[0079]

[0080] in is the second atmospheric phase, is the atmospheric pressure P at time t t and the corrected temperature f(T t ) calculated atmospheric phase, is the corrected relative humidity at time t g(RH t ) calculated atmospheric phase;

[0081] Determine the relative humidity correction model coefficient optimization objective function AIM2, the expression is:

[0082]

[0083] Continuously optimize and adjust the relative humidity correction model coefficients. When the objective function AIM2 is minimized, the corresponding relative humidity correction model coefficients are output. The relative humidity correction model is updated and output using the relative humidity correction model coefficients. The relative humidity of the stable reference point is input into the relative humidity correction model to obtain the corrected relative humidity.

[0084] In the actual evaluation, the electronic meteorological instrument temperatures of reference points 1, 3, 5, and 7 were input into the temperature correction model to obtain corrected temperatures of 20.3, 20.4, 20.2, and 20.4 (unit: ℃). The correction model coefficients were optimized to coefficients β0=10, β1=0.9, and β2=-0.003 according to the corrected temperatures, relative humidity, and atmospheric pressure. The relative humidity of reference points 1, 3, 5, and 7 were input into the humidity correction model to obtain corrected relative humidity temperatures of 41.2%, 41.9%, 40.5%, and 41.2%.

[0085] In this embodiment, the method for determining the micro-deformation of the target point includes:

[0086] Calculate the second atmospheric phase based on the corrected temperature, corrected relative humidity and atmospheric pressure Perform atmospheric compensation and calculate the micro deformation of the ground-based radar target point based on the atmospheric compensation result:

[0087]

[0088] in is the differential phase after atmospheric compensation, is the ground-based radar acquisition phase at time t The corresponding interference phase, Δd is the micro-deformation of the ground-based radar target point, and λ is the wavelength of the electromagnetic wave emitted by the ground-based radar;

[0089] In the actual evaluation, the monitoring target point was selected, and the electronic meteorological data of the target point was obtained as 20.3℃, 40.2%, and 1010hPa. The meteorological data after correction by the temperature correction model and the humidity correction model was 20.5℃, 41.3%, and 1010hPa. The second atmospheric phase was calculated to be 6280.5rad, and the interference phase corresponding to the ground-based radar acquisition phase was 6280.55rad. The differential phase after atmospheric compensation was calculated to be 0.05rad. According to the atmospheric compensation result, the micro-deformation of the ground-based radar target point was calculated to be 1.963495mm.

[0090] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for correcting atmospheric parameters of ground-based radar based on meteorological parameter correction, characterized in that: It includes the following steps: S1. Determine a reference point according to the range bin of the ground-based radar, and obtain the temperature of the mercury thermometer and the electronic meteorological data at the reference point; the electronic meteorological data includes the temperature of the electronic meteorograph, the relative humidity, and the atmospheric pressure; S2. Construct a temperature correction model based on the temperature of the mercury thermometer and the electronic meteorograph data; S3. Calculate the first atmospheric phase according to the electronic meteorological data, determine a stable reference point according to the first atmospheric phase, and input the temperature of the electronic meteorograph at the stable reference point into the temperature correction model to obtain a corrected temperature; S4. Construct a relative humidity correction model according to the corrected temperature, and input the relative humidity at the stable reference point into the relative humidity correction model to obtain a corrected relative humidity; S5. Perform atmospheric compensation according to the corrected temperature and the corrected relative humidity, and determine the micro-deformation of the target point according to the atmospheric compensation result.

2. The method for correcting atmospheric parameters of ground-based radar based on meteorological parameter correction according to claim 1, characterized in that: The method for constructing the temperature correction model includes: Set a thermal signal-to-noise ratio threshold to screen the reflection points to obtain reference points, and obtain the temperature of the mercury thermometer and the electronic meteorological data at the reference points; The temperature data is divided into a training set and a test set; the temperature data is specifically the mercury thermometer temperature T i y and electronic weather instrument temperature T i x , i=1,2,…,n, n is the number of temperatures collected; Determine the order m of the temperature correction model according to the Bayesian information criterion, where m < n, and construct an (m + 1)-order temperature correction model. The expression is: f(T i x )=α0+α1T i x +α2(T i x ) 2 +…+a m (T i x ) m Where f(T i x ) is the temperature of the electronic meteorological instrument, T i x Corrected temperature at i ∈{α0,α1,α2,…,α m } is the temperature correction model coefficient; Determine the optimization objective function AIM1 of the temperature correction model coefficients. The expression is: Input the training set data into the objective function AIM1 to fit the temperature correction model coefficient α i When the objective function AIM1 is minimum, the corresponding temperature correction model coefficient α is output i , using α i Update the temperature correction model, use the test set data to verify the temperature correction model, and output the temperature correction model.

3. The method for correcting atmospheric parameters of ground-based radar based on meteorological parameter correction according to claim 1, characterized in that: The method for determining the stable reference point includes: Calculate the first atmospheric phase according to the electronic meteorological data of the reference point. The expression is: in is the first atmospheric phase, λ is the wavelength of the electromagnetic wave emitted by the ground-based radar, r is the monitoring distance of the target point from the radar, N is the atmospheric refractive index in the monitoring environment at time t, is the temperature of the electronic meteorological instrument at time t, P t is the atmospheric pressure at time t, RH t is the relative humidity at time t; Perform secondary screening on the reference points according to the first atmospheric phase to obtain stable reference points. The screening condition is: in is the ground-based radar acquisition phase at time t The corresponding interference phase, S is an unbiased estimator.

4. The method for correcting atmospheric parameters of ground-based radar based on meteorological parameter correction according to claim 3, characterized in that: The method for obtaining the corrected relative humidity includes: Determine the relative humidity correction model. The expression is: g(RH t )=β0+β1RH t +β2(RH t ) 2 Where g(RH t ) is the relative humidity at time t, RH t Corrected relative humidity at , β0, β1, β2 are relative humidity correction model coefficients; Calculate the second atmospheric phase according to the corrected temperature, the corrected relative humidity, and the atmospheric pressure. The expression is: in is the second atmospheric phase, is the atmospheric pressure P at time t t and the corrected temperature f(T t ) calculated atmospheric phase, is the corrected relative humidity at time t g(RH t ) calculated atmospheric phase; Determine the optimization objective function AIM2 of the relative humidity correction model coefficients. The expression is: Continuously optimize and adjust the coefficients of the relative humidity correction model. When the objective function AIM2 is minimized, output the corresponding coefficients of the relative humidity correction model, update and output the relative humidity correction model using the coefficients of the relative humidity correction model, and input the relative humidity at the stable reference point into the relative humidity correction model to obtain the corrected relative humidity.

5. The method for correcting atmospheric parameters of ground-based radar based on meteorological parameter correction according to claim 1, characterized in that: The method for determining the micro-deformation of the target point includes: Calculate the second atmospheric phase based on the corrected temperature, corrected relative humidity and atmospheric pressure Perform atmospheric compensation and calculate the micro deformation of the ground-based radar target point based on the atmospheric compensation result: in is the differential phase after atmospheric compensation, is the ground-based radar acquisition phase at time t The corresponding interference phase, Δd is the micro-deformation of the ground-based radar target point, and λ is the wavelength of the electromagnetic wave emitted by the ground-based radar.

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