Improved atmospheric waveguide sounding information denoising preprocessing method

Abstract

The application provides an improved atmospheric waveguide sounding information denoising preprocessing method, which comprises wavelet denoising and Hilbert-Huang transform-based denoising, and the wavelet denoising and the Hilbert-Huang transform-based denoising are both performed by using a sounding balloon and a sounding device to collect meteorological parameters in the atmosphere; a frame is mounted on the side of the sounding balloon; a connecting pipe is arranged at the bottom of the sounding balloon; a temperature and humidity sensing module and an air flow sensing module are mounted in the sounding device; the improved atmospheric waveguide sounding information denoising preprocessing method can process wavelet coefficients in the form of a threshold value, and then reconstruct the signal to achieve the purpose of denoising; or the signal noise ratio can be improved through autocorrelation analysis, and the purpose of reducing noise can be effectively achieved; a balance assembly and a micro motor are mounted at the bottom of the sounding balloon, so that the detection accuracy of the sensor is improved.

Description

Technical Field

[0001] This invention relates to the field of meteorological detection technology, specifically to an improved method for noise reduction and preprocessing of atmospheric waveguide radiosonde information. Background Technology

[0002] Atmospheric waveguides are a collective term for atmospheric layers that can affect the propagation of electromagnetic waves. Based on their altitude, they can be classified into three types: evaporation waveguides, surface waveguides, and rise waveguides. To accurately obtain detailed data on different types of atmospheric waveguides, radiosonde equipment is typically used for data collection. However, in actual measurements, typical corrected refractive index profiles of atmospheric waveguides have not been observed; instead, numerous instances of altitude "reversal" have been found.

[0003] This phenomenon makes the profile "chaotic," which brings great difficulty to researchers in judging the characteristic information of the evaporation waveguide. The reason for this is the measurement error caused by the accuracy of the sensor. Therefore, it is necessary to perform noise reduction processing on the radiosonde data containing "noise" by combining the characteristics of the radiosonde data with the corresponding algorithm. At the same time, the accuracy of the data measured by the sensor in the radiosonde equipment also needs to be improved. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide an improved method for noise reduction and preprocessing of atmospheric duct radiosonde data, thereby solving the problems mentioned in the background section. This invention can effectively reduce the noise of noisy radiosonde data, while improving the accuracy of measurements and helping researchers determine the characteristic information of evaporation ducts.

[0005] To achieve the above objectives, the present invention provides an improved atmospheric waveguide radiosonde information noise reduction preprocessing method, comprising wavelet noise reduction and Hilbert-Huang transform-based noise reduction. Both wavelet noise reduction and Hilbert-Huang transform-based noise reduction involve collecting meteorological parameters in the atmosphere using a radiosonde balloon and a radiosonde device. The radiosonde balloon has a frame mounted on its side and a connecting pipe at its bottom. The radiosonde device is equipped with a temperature and humidity sensing module and an airflow sensing module. A pressure relief chamber is installed at the bottom of the radiosonde device, and a balancing component is installed at the bottom of the pressure relief chamber. After collecting air pressure data through the radiosonde device, wavelet noise reduction and Hilbert-Huang transform-based noise reduction are performed to obtain the final corrected refractive index profile.

[0006] Furthermore, in the wavelet denoising process, the coefficients obtained after wavelet decomposition are processed to complete the subsequent denoising.

[0007] Furthermore, the wavelet coefficients are processed in the form of thresholds, and then the signal is reconstructed. At the same time, during noise reduction, thresholds are selected according to the different characteristics of each layer, while avoiding the loss of high-frequency information of the signal due to too many layers.

[0008] Furthermore, in the Hilbert-Huang transform denoising process, the noisy signal is first decomposed, and then autocorrelation processing can be performed to achieve denoising.

[0009] Furthermore, the process of decomposing noisy signals includes empirical mode decomposition of the atmospheric corrected refractive index M in the acquired noisy sounding data.

[0010] Furthermore, based on the autocorrelation processing results, the noise reduction results are finally obtained through reconstruction analysis using different permutations and combinations.

[0011] Furthermore, a pull rope is connected to the bottom of the frame, the bottom end of the pull rope is connected to the balancing component, a micro motor is installed inside the pressure relief chamber, a bracket is installed on the side of the output end of the micro motor, an arc-shaped baffle is installed at the end of the bracket, and a sealing layer is attached to the outside of the arc-shaped baffle.

[0012] Furthermore, the surface of the pressure relief chamber is provided with air vents, the arc-shaped baffle is pressed against the inner wall of the pressure relief chamber through the sealing layer on the surface, a guide pipe is installed on the top of the pressure relief chamber, and the interior of the pressure relief chamber is connected to the interior of the weather balloon through the guide pipe and connecting pipe.

[0013] Furthermore, the balancing component includes a water storage ring and a buffer tank. A water supply pipe is connected to the inner side of the water storage ring, a buffer tank is installed in the middle of the water supply pipe, and a solenoid valve is installed at the bottom of the buffer tank.

[0014] Furthermore, the water storage ring is filled with clean water, and the top of the water storage ring is connected to the edge of the frame by a pull rope. The buffer tank, water supply pipe and the interior of the water storage ring are connected.

[0015] The beneficial effects of this invention are:

[0016] 1. The improved atmospheric waveguide radiosonde information noise reduction preprocessing method combines the characteristics of radiosonde data with corresponding algorithms to perform noise reduction processing on radiosonde data containing "noise". Wavelet coefficients can be processed in the form of thresholds, and then the signal can be reconstructed to achieve the purpose of noise reduction. Alternatively, autocorrelation analysis can be used to improve the signal-to-noise ratio of the signal and effectively reduce noise.

[0017] 2. In this improved atmospheric waveguide radiosonde information noise reduction preprocessing method, by installing a balancing component at the bottom of the radiosonde balloon, the balance between the lift and load of the radiosonde balloon can be controlled by using a control solenoid valve in conjunction with a micro motor at the top. Therefore, it can achieve the effect of temporary hovering or deceleration, and in this state, meteorological data can be collected using radiosonde equipment, thereby improving the accuracy of sensor detection. Attached Figure Description

[0018] Figure 1 The above is a diagram of measured atmospheric sounding pressure data for an improved atmospheric waveguide sounding information noise reduction and preprocessing method according to the present invention.

[0019] Figure 2 This is a schematic diagram of wavelet decomposition for an improved atmospheric waveguide sounding information noise reduction preprocessing method according to the present invention.

[0020] Figure 3 The image shows the result of wavelet denoising after processing using an improved atmospheric waveguide sounding information denoising preprocessing method according to the present invention.

[0021] Figure 4 This is an EMD decomposition result of M in an improved atmospheric waveguide radiosonde information noise reduction preprocessing method of the present invention.

[0022] Figure 5 This is the first set of autocorrelation results in an improved atmospheric waveguide sounding information noise reduction preprocessing method of the present invention;

[0023] Figure 6 This is the second set of autocorrelation results in an improved atmospheric waveguide sounding information noise reduction preprocessing method of the present invention;

[0024] Figure 7 The image shows the result of Hilbert-Huang noise reduction after processing using an improved atmospheric waveguide sounding information noise reduction preprocessing method according to the present invention.

[0025] Figure 8 This is a structural diagram of the acquisition equipment used in the improved atmospheric waveguide sounding information noise reduction and preprocessing method of the present invention;

[0026] Figure 9 This is a schematic diagram of the sounding equipment part of the improved atmospheric waveguide sounding information noise reduction preprocessing method of the present invention;

[0027] Figure 10 This is a cross-sectional view of the pressure relief chamber in the data acquisition device of the present invention;

[0028] Figure 11 This is a schematic diagram of the structure of some balancing components in the data acquisition device of the present invention;

[0029] In the diagram: 1. Weather balloon; 2. Frame; 3. Pull rope; 4. Weathering equipment; 5. Balancing assembly; 6. Control module; 7. Temperature and humidity sensing module; 8. Airflow sensing module; 9. Connecting pipe; 10. Pressure relief chamber; 11. Guide pipe; 12. Micro motor; 13. Bracket; 14. Arc-shaped baffle; 15. Sealing layer; 16. Air outlet; 17. Water storage ring; 18. Water supply pipe; 19. Buffer tank; 20. Solenoid valve. Detailed Implementation

[0030] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0031] Please see Figures 1 to 11 This invention provides a technical solution: an improved atmospheric waveguide radiosonde information noise reduction preprocessing method, including wavelet denoising and Hilbert-Huang transform-based denoising. Both wavelet denoising and Hilbert-Huang transform-based denoising involve collecting meteorological parameters in the atmosphere using a radiosonde balloon 1 and a radiosonde device 4. Generally, when measuring meteorological data via radiosonde, the measurement signal model is m(t) = s(t) + n(t), where m(t) is the noisy meteorological data measured by the sensor, s(t) is the actual meteorological signal, and n(t) is the noise. Figure 1 Taking a set of atmospheric pressure data measured by radiosonde 4 as an example, the measured signal m(t) gradually decreases with increasing time, and its mean is not constant, thus it is a non-stationary signal. For this type of signal, it is better to use a method that can perform multi-scale analysis of the signal and characterize the local information of the signal in both the time and frequency domains. Wavelets and Hilbert-Huang transforms have this characteristic.

[0032] In this embodiment, during the wavelet denoising process, wavelet transform has the ability to characterize the local features of a signal in both the time and frequency domains. Furthermore, in real-world environments, real signals are generally low-frequency signals, while noise often manifests as high-frequency signals. The wavelet coefficients corresponding to these two types of signals have different characteristics at the wavelet decomposition scale. Therefore, certain rules can be constructed to appropriately process the coefficients obtained after wavelet decomposition to achieve the purpose of noise reduction. Figure 2 Taking three-level wavelet decomposition as an example, after selecting a wavelet, the signal S is decomposed. CA3 is called the approximation signal, which corresponds to the low-frequency part of the signal. CD1, CD2, and CD3 are called detail signals, which correspond to the high-frequency components of the signal. The relationship between the above signals and S is as follows: The noise component is usually contained in CD1, CD2, and CD3. Therefore, the wavelet coefficients can be processed in the form of thresholds, and then the signal can be reconstructed to achieve the purpose of noise reduction.

[0033] Specifically, considering that thresholds should be selected according to the different characteristics of each layer during noise reduction, and to avoid the loss of high-frequency information due to too many layers, the sym4 wavelet is selected to decompose the signal into four layers in the actual data noise reduction, and a layered soft thresholding method is used to denoise the noisy signal. The wavelet-derived noise reduction result is as follows: Figure 3 As shown.

[0034] In this embodiment, the Hilbert-Huang transform method can decompose nonlinear, non-stationary signals into a sum of finite intrinsic mode function (IMF) components that characterize the signal's time scale. These components contain information from different frequency bands of the signal from high to low. The frequency resolution of each frequency band varies with the signal, thus exhibiting the characteristics of adaptive multi-resolution analysis.

[0035] The noisy signal is decomposed using the Hilbert-Huang transform, and autocorrelation processing can then be performed to reduce noise. Autocorrelation aims to understand the dependency or similarity between a signal at a given moment and a signal at a previous moment; generally, it reflects the degree of similarity between the signal and itself after a delay. Since the signal is only related to itself and not to noise, and noise is also uncorrelated, with noise reaching its maximum value at zero and decaying to zero elsewhere, autocorrelation analysis can significantly improve the signal-to-noise ratio and effectively reduce noise.

[0036] Specifically, empirical mode decomposition (EMD) was performed on the atmospheric corrected refractive index M in the collected noisy radiosonde data. The results are shown in Figure 5. Figure 4 Based on the results, autocorrelation processing is performed to obtain the following results: Figure 5 As shown, similarly, autocorrelation processing is performed on the four IMF functions of height z, including the residual R, and the results are as follows. Figure 6 As shown, based on the autocorrelation processing results of M and z, through different permutations and combinations of reconstruction analysis, the final denoising result is obtained as follows. Figure 7 As shown.

[0037] The results obtained above show that both methods can effectively reduce noise in sounding data. Wavelet denoising is slightly better, and the denoised result does not show a significant "oscillation" effect. Although the Hilbert-Huang transform-based denoising method has filtered out most of the noise components, the "oscillation" effect still exists.

[0038] In this embodiment, a frame 2 is installed on the side of the weather balloon 1, and a connecting pipe 9 is provided at the bottom of the weather balloon 1. A temperature and humidity sensing module 7 and an airflow sensing module 8 are installed in the weather radiosonde device 4. A pressure relief chamber 10 is installed at the bottom of the weather radiosonde device 4, and a balancing component 5 is installed at the bottom of the pressure relief chamber 10. After the weather radiosonde device 4 collects air pressure data, wavelet noise reduction and Hilbert-Huang transform-based noise reduction processing are performed to obtain the final corrected refractive index profile. By installing the balancing component 5 at the bottom of the weather balloon 1, the lift of the weather balloon 1 and the balance between the load can be controlled by using the control solenoid valve 20 in conjunction with the micro motor 12 at the top. Therefore, the effect of temporary hovering or deceleration can be achieved, and meteorological data can be collected by the weather radiosonde device 4 in this state, thereby improving the accuracy of sensor detection.

[0039] In this embodiment, a pull rope 3 is connected to the bottom of the frame 2, and the bottom end of the pull rope 3 is connected to the balancing component 5. A micro motor 12 is installed inside the pressure relief chamber 10. A bracket 13 is installed on the side of the output end of the micro motor 12, and an arc-shaped baffle 14 is installed at the end of the bracket 13. A sealing layer 15 is attached to the outer side of the arc-shaped baffle 14. An air vent 16 is opened on the surface of the pressure relief chamber 10. The arc-shaped baffle 14 is pressed against the inner wall of the pressure relief chamber 10 through the sealing layer 15 on its surface. A flow guide pipe 11 is installed at the top. The interior of the pressure relief chamber 10 is connected to the interior of the weather balloon 1 through the flow guide pipe 11 and the connecting pipe 9. Specifically, by controlling the rotation of the micro motor 12, the micro motor 12 drives the arc-shaped baffle 14 to rotate through the bracket 13, and finally blocks and covers the position of the air outlet 16. By controlling the coverage of the air outlet 16, the pressure inside the weather balloon 1 is released. With the control of its own weight by the bottom balance component 5, the lifting speed of the entire weather balloon 1 can be adjusted.

[0040] In this embodiment, the balancing component 5 includes a water storage ring 17 and a buffer tank 19. A water supply pipe 18 is connected to the inner side of the water storage ring 17, and the buffer tank 19 is installed in the middle of the water supply pipe 18. A solenoid valve 20 is installed at the bottom of the buffer tank 19. The water storage ring 17 is filled with clean water, and the top of the water storage ring 17 is connected to the edge of the frame 2 by a pull rope 3. The buffer tank 19, the water supply pipe 18, and the interior of the water storage ring 17 are connected. Specifically, by opening the solenoid valve 20, the clean water inside the water storage ring 17 can be discharged, thereby achieving the effect of weight reduction. By controlling the micro motor 12 to depressurize the sounding balloon 1, the lift effect can be reduced. By controlling the two sets of structures, the effort reduction and the weight of the entire device can be balanced, so that the entire device can achieve a near-hovering effect. In this state, the impact of the airflow generated during the rise on the sensors in the sounding device 4 is reduced, thereby improving the accuracy of sensor detection.

[0041] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0042] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An improved atmospheric waveguide sounding information denoising preprocessing method, characterized in that: The application relates to a meteorological parameter collecting device for collecting meteorological parameters in the atmosphere by using a sounding balloon (1) and a sounding device (4), wherein a frame (2) is arranged on the side of the sounding balloon (1), a connecting pipe (9) is arranged at the bottom of the sounding balloon (1), a control module (6), a temperature and humidity sensing module (7) and an air flow sensing module (8) are arranged in the sounding device (4), a pressure relief bin (10) is arranged at the bottom of the sounding device (4), and a balance assembly (5) is arranged at the bottom end of the pressure relief bin (10); after collecting pressure data by the sounding device (4), wavelet denoising or Hilbert-Huang transform denoising is carried out to obtain a final corrected refractive index profile. A pull rope (3) is connected to the bottom of the frame (2), the bottom end of the pull rope (3) is connected to the balance assembly (5), a micro motor (12) is arranged in the pressure relief bin (10), a support (13) is arranged at the output end of the micro motor (12), an arc-shaped baffle (14) is arranged at the tail end of the support (13), a sealing layer (15) is attached to the outer side of the arc-shaped baffle (14), a gas outlet hole (16) is arranged on the surface of the pressure relief bin (10), the arc-shaped baffle (14) is pressed on the inner wall of the pressure relief bin (10) through the sealing layer (15) on the surface of the arc-shaped baffle (14), a flow guide pipe (11) is arranged at the top of the pressure relief bin (10), the inside of the pressure relief bin (10) is connected to the inside of the sounding balloon (1) through the flow guide pipe (11) and the connecting pipe (9), the balance assembly (5) comprises a water storage ring (17) and a buffer tank (19), the inside of the water storage ring (17) is connected to a water delivery pipe (18), the middle of the water delivery pipe (18) is arranged with the buffer tank (19), the bottom end of the buffer tank (19) is arranged with an electromagnetic valve (20), clean water is injected into the inside of the water storage ring (17), the top of the water storage ring (17) is connected to the edge of the frame (2) through the pull rope (3), and the inside of the buffer tank (19), the water delivery pipe (18) and the water storage ring (17) is connected.

2. The improved atmospheric waveguide sounding information denoising preprocessing method according to claim 1, characterized in that: In the wavelet denoising process, the coefficients obtained after wavelet decomposition are processed to complete subsequent noise elimination.

3. The improved atmospheric waveguide sounding information denoising preprocessing method according to claim 2, characterized in that: The wavelet coefficients are processed in the form of a threshold value, and then the signal is reconstructed, and the threshold value is selected according to the different characteristics of each layer during noise reduction, and the loss of high-frequency information of the signal caused by too many layers is avoided.

4. The improved atmospheric waveguide sounding information denoising preprocessing method according to claim 1, characterized in that: In the Hilbert-Huang transform denoising process, the noisy signal is first decomposed, and autocorrelation processing is carried out on the basis to realize noise reduction.

5. The improved atmospheric waveguide sounding information denoising preprocessing method according to claim 4, characterized in that: The autocorrelation processing result is used as a basis to finally obtain the noise reduction result through different permutation and combination reconstruction analysis.

6. The improved atmospheric waveguide sounding information denoising preprocessing method according to claim 5, characterized in that: ​

Images