X-band radar secondary echo networking identification and rejection method, system and device

Abstract

The invention discloses an X-band radar secondary echo networking identification and elimination method, system and device, and relates to the field of meteorological radar detection, and the method comprises the steps: S1, obtaining S-band, C-band and X-band radar base data; s2, preprocessing radar base data; s3, extracting suspected secondary echo regions to form a suspected set; splicing the S / C wave band radar and extracting a strong echo region to form a strong echo target set; s4, analyzing each suspected secondary echo region and the strong echo target set in the suspected set to obtain an analysis result; s5, eliminating the secondary echoes of the X-band radar according to an analysis result to obtain X-band radar data after elimination; according to the method, logic judgment is carried out by combining external puzzle verification with a space matching strategy, so that the physical certainty and reliability of the criterion are greatly improved; effective and accurate recognition under the complex conditions that the secondary echo form is not typical, the speed field is disordered due to the weather system, and the primary echo and the secondary echo are overlapped in the same distance library is achieved.

Description

Technical Field

[0001] This invention relates to the field of meteorological radar detection, and in particular to a method, system, and device for identifying and eliminating secondary echo networks of X-band radar. Background Technology

[0002] Severe convective weather (such as short-duration heavy rainfall, thunderstorms, hail, and tornadoes) is characterized by its sudden onset, small scale, short lifespan, and high destructiveness, making it a key focus and challenge in weather forecasting and early warning. Weather radar, due to its high spatiotemporal resolution, has become the most effective tool for monitoring this type of weather. In recent years, X-band weather radar, especially X-band phased array radar, has demonstrated great potential in compensating for the detection blind spots of operational S-band radar and capturing rapidly evolving small- and medium-scale systems due to its advantages such as fast scanning speed (volume scan time can be reduced to within 1 minute), no blind spots in the near-surface layer, and flexible deployment.

[0003] However, the inherent "Doppler dilemma" of Doppler radar severely limits its detection performance. This problem refers to the fact that the product of the radar's maximum unambiguous range (Rmax) and maximum unambiguous velocity (Vmax) is a constant and cannot be maximized simultaneously. To obtain sufficient velocity detection range (especially for X-band radars, which have shorter wavelengths and are more sensitive to velocity ambiguity), a higher pulse repetition frequency (PRF) is often required, but this leads to a significant reduction in Rmax. When the actual meteorological target is outside Rmax, its echo will be received in the next (or several) pulse cycles and incorrectly displayed at a false location within Rmax; this is known as "secondary echo" or "range ambiguity echo." Although the secondary echo is a real meteorological signal, its location information is completely erroneous. If it cannot be effectively identified and eliminated, it will seriously affect the accuracy of radar data in advanced applications such as quantitative precipitation estimation, strong convective structure identification, and wind field inversion.

[0004] To alleviate or resolve the secondary echo problem, existing technologies employ suppression and deblurring techniques at the signal processing level and identification techniques at the data / product processing level. The drawbacks of existing technologies are the inherent limitations of single-station identification methods, hardware dependence and performance bottlenecks of signal processing methods, and the "cognitive blind spot" of lacking independent external verification. Summary of the Invention

[0005] The purpose of this invention is to design a method, system, and device for identifying and eliminating secondary echo networks of X-band radar in order to solve the above-mentioned problems.

[0006] The present invention achieves the above objectives through the following technical solutions:

[0007] Methods for identifying and eliminating secondary echo networks from X-band radar include:

[0008] S1. Acquire S-band, C-band, and X-band weather radar base data covering the target area;

[0009] S2. Preprocessing of the acquired S-band, C-band and X-band weather radar base data by denoising and ground clutter filtering;

[0010] S3. Perform feature identification on the preprocessed X-band radar data, extract all suspected secondary echo regions, and form a suspected set R. x ;

[0011] S4. After performing coordinate transformation on the preprocessed S-band and C-band radar data, mosaicking is performed using the maximum value method, and all strong echo regions in the mosaic are extracted to form a set of strong echo targets S. c ;

[0012] S5, regarding the suspected set R x Each suspected secondary echo region and the set of strong echo targets S c A spatial logic matching strategy is used for matching analysis; based on the analysis results, the secondary echo data of the X-band radar is removed to obtain the X-band quality control data after removal.

[0013] The X-band radar secondary echo network identification and elimination system is used to implement the X-band radar secondary echo network identification and elimination method described above, including:

[0014] Acquisition module; The acquisition module is used to acquire S-band, C-band, and X-band weather radar base data of the target area;

[0015] Preprocessing module; The preprocessing module is used to filter and remove ground clutter from S-band, C-band and X-band weather radar base data;

[0016] The feature initial judgment module and the feature extraction module are used to identify features in the preprocessed X-band radar data and extract all suspected secondary echo regions to form a suspected set R. x ;

[0017] Target extraction module; the target extraction module is used to extract all strong echo regions from the preprocessed mosaic, forming a set of strong echo targets S. c ;

[0018] Spatial logical matching decision module; the spatial logical matching decision module performs a selection of the suspected set R. x Each suspected secondary echo region and the set of strong echo targets S c The spatial logic matching strategy is used to perform matching analysis and obtain the analysis results;

[0019] Quality control execution and output module: The quality control execution and output module performs elimination processing on the X-band radar base data based on the analysis results, and obtains and outputs the eliminated X-band radar data.

[0020] X-band radar secondary echo network identification and rejection device, including:

[0021] Storage; storage is used to store computer programs;

[0022] Actuator; the actuator is used to execute a computer program stored in the memory, which, when executed, implements the X-band radar secondary echo network identification and elimination method as described above.

[0023] The beneficial effects of this invention are as follows: This method uses a spatial logic matching strategy of external large-scale jigsaw puzzle to perform logical judgment verification, which greatly improves the physical certainty and reliability of the criterion; it achieves effective and accurate identification in complex situations such as atypical secondary echo morphology, chaotic velocity field due to the weather system itself, and primary and secondary echoes superimposed at the same distance. Attached Figure Description

[0024] Figure 1 A flowchart illustrating the X-band radar secondary echo network identification and elimination method of the present invention;

[0025] Figure 2 A schematic diagram of S4 in the X-band radar secondary echo network identification and elimination method of the present invention;

[0026] Figure 3 A schematic diagram of the X-band radar secondary echo network identification and elimination system of the present invention;

[0027] Figure 4 A schematic diagram of X-band radar secondary echo identification according to the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0030] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0031] In the description of this invention, it should be understood that the terms "upper," "lower," "inner," "outer," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0032] Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0033] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, terms such as "set" and "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0034] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0035] like Figure 1 , Figure 2 As shown, the method for identifying and eliminating secondary echoes from X-band radar networks includes:

[0036] S1. Acquire S-band, C-band, and X-band weather radar base data for the target area.

[0037] S2. Preprocess the acquired S-band, C-band, and X-band weather radar base data by denoising and filtering out ground clutter.

[0038] S3. Perform feature identification on the preprocessed X-band radar data, extract all suspected secondary echo regions, and form a suspected set R. xThe feature identification of the preprocessed X-band radar base data is as follows: the region that meets the first condition or the second condition is regarded as the suspected secondary echo region; the first condition is: the radial direction of the preprocessed X-band radar near-range reflectivity factor shows a narrow and elongated strip or arc structure, and it only appears within the preset elevation angle range, which is below 6.0° elevation angle; the second condition is: when the standard deviation of the distribution of the weak echo radial velocity in the narrow local area near range shows incoherence (the adjacent range or azimuth angular velocity values ​​jump) exceeds a certain threshold, the threshold can be obtained by statistically analyzing the velocity spectrum width parameter based on the local radar secondary echo characteristics (the velocity spectrum width reflects the degree of "dispersion" or "chaos" of the velocity of different particles within the radar beam illumination volume).

[0039] S4. After performing coordinate transformation on the preprocessed S-band and C-band radar data, mosaicking is performed using the maximum value method. All strong echo regions in the mosaic are extracted to form a set of strong echo targets, S. c ;

[0040] S5, regarding the suspected set R x Each suspected secondary echo region and the set of strong echo targets S c The spatial logic matching strategy is used to perform matching analysis and obtain the analysis results;

[0041] The matching analysis using a spatial logic matching strategy specifically includes:

[0042] (1) Identify the suspected secondary echo area Relative azimuth angle in the X-band radar polar coordinate system and center distance Where i∈N, and N is the set of possible cases R. x The total number of suspected secondary echo areas in the middle;

[0043] (2) Set S of strong echo targets c Mapped to the polar coordinate system of the corresponding X-band radar station, this becomes the mapped set of strong echo targets. ;

[0044] (3) Use spatial logic matching strategy to identify suspected secondary echo areas and the mapped set of strong echo targets Perform a search and match to obtain the judgment result; specifically including:

[0045] ① Determine the set of targets with strong echoes If the value is empty, the result is negative; otherwise, proceed to step ②.

[0046] ②Analyze each strong echo region after mapping With suspected secondary echo area Are the relative positions between them within the preset range, such as... Figure 4 As shown, if not, the result is negative; otherwise, proceed to step ③.

[0047] ③ Determine the area mapped to the corresponding X-band radar strong echo region. Distance and suspected secondary echo area If the true distance R after de-ambiguation exceeds the distance threshold, the result is confirmed; otherwise, the result is denied. The distance ambiguity arises from the previous (or first few) transmitted pulses in the echo signal received by the X-band radar. Therefore, the true distance R after de-ambiguation is expressed as: Where m represents the number of ambiguities, which is an integer; c is the speed of light; PRF is the pulse repetition frequency of the radar scan; R m This is the display distance of the X-band radar corresponding to the suspected secondary echo distance.

[0048] S5. Confirm the secondary echo region in the set. The X-band radar base data is processed to remove data, and the removed X-band radar data is either written into the quality control base data for subsequent applications.

[0049] Through collaborative verification with internal and external data, the misjudgment and missed judgment rates of single-station algorithms under complex weather conditions are significantly reduced, especially in effectively handling the challenges of atypical morphology and overlapping ambiguity. This method can be widely applied to various deployed and newly built X-band weather radar systems with low implementation threshold. Combining internal feature preliminary judgment and external space verification as a dual evidence chain, the quality control logic is more robust and has strong anti-interference capabilities. Utilizing the rapid mosaicking of operational S / C-band radar (with an update cycle typically of 6 minutes), it can meet the data timeliness requirements for real-time monitoring and early warning of severe convective weather, achieving near real-time secondary echo quality control.

[0050] like Figure 3 As shown, the X-band radar secondary echo network identification and elimination system is used to implement the X-band radar secondary echo network identification and elimination method described above, including:

[0051] Acquisition module; The acquisition module is used to acquire S-band, C-band, and X-band radar base data of the target area;

[0052] Preprocessing module; The preprocessing module is used to perform preprocessing such as filtering and ground clutter removal on the acquired S-band, C-band and X-band weather radar base data;

[0053] The feature initial judgment module and the feature extraction module are used to identify features in the preprocessed X-band radar data and extract all suspected secondary echo regions to form a suspected set R. x ;

[0054] Target extraction module; the target extraction module is used to extract all strong echo regions from the preprocessed mosaic, forming a set of strong echo targets S. c ;

[0055] Spatial logical matching decision module; the spatial logical matching decision module performs a selection of the suspected set R. x Each suspected secondary echo region and the set of strong echo targets S c Matching analysis is performed using relative orientation and distance matching strategies to obtain analysis results;

[0056] Quality control execution and output module: The quality control execution and output module performs elimination processing on the X-band radar base data according to the analysis results, and obtains and outputs the eliminated X-band radar data or writes it into the base data after quality control.

[0057] X-band radar secondary echo network identification and rejection device, including:

[0058] Storage; storage is used to store computer programs;

[0059] Actuator; the actuator is used to execute a computer program stored in the memory, which, when executed, implements the X-band radar secondary echo network identification and elimination method as described above.

[0060] This system consists of three parts: data source, processing center, and output product. The data source includes base data generated by S-band, C-band, and X-band radars undergoing quality control. The processing center contains five functional modules that process, analyze, and make decisions on the data sequentially. The final output is an X-band radar product that has undergone quality control and has had secondary echoes removed. The data preprocessing module is responsible for formatting and noise filtering the raw data; the single-station feature preliminary judgment module initially screens out suspected secondary echo areas based on the X-band radar's own data; the external mosaic strong target extraction module extracts strong echo targets from a large-scale mosaic; the spatial logic matching decision module (core) spatially correlates the internal preliminary judgment results with external strong targets, making a final judgment based on "azimuth matching" and "range verification"; the quality control execution and output module marks or removes data according to the judgment results. The final output product is a high-quality X-band radar data product that has undergone quality control and has had false secondary echoes removed. The entire process embodies a complete closed loop from multi-source data input and collaborative processing to high-quality product output; it enables the verification and precise removal of secondary echoes, which is of great practical significance for improving the data reliability and application value of high spatiotemporal resolution X-band radar networks.

[0061] The technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made in accordance with the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. A method for identifying and eliminating secondary echo networks from X-band radar, characterized in that, include: S1. Acquire S-band, C-band, and X-band weather radar base data covering the target area; S2. Preprocessing of the acquired S-band, C-band and X-band weather radar base data by denoising and ground clutter filtering; S3, feature recognition is performed on the pretreated X-band radar data, all suspected secondary echo regions are extracted, and a suspected set R is formed x ; S4. After performing coordinate transformation on the preprocessed S-band and C-band radar data, mosaicking is performed using the maximum value method, and all strong echo regions in the mosaic are extracted to form a set of strong echo targets S. c ; S5, regarding the suspected set R x Each suspected secondary echo region and the set of strong echo targets S c A spatial logic matching strategy is used for matching analysis; based on the analysis results, the secondary echo data of the X-band radar is removed to obtain the X-band quality control data after removal.

2. The method for identifying and eliminating X-band radar secondary echo networks according to claim 1, characterized in that, In S3, the feature identification of the preprocessed X-band radar data is specifically as follows: the area that meets the first condition or the second condition is regarded as the suspected secondary echo area; the first condition is: the near-range reflectivity factor of the preprocessed X-band radar shows a narrow and elongated strip or arc-shaped structure in the radial direction, and appears only within the preset elevation angle range; the second condition is: the radial velocity of the weak echo in the narrow local area at close range shows an incoherent distribution standard deviation exceeding the preset threshold.

3. The method for identifying and eliminating X-band radar secondary echo networks according to claim 1, characterized in that, In S5, a spatial logic matching strategy is used to perform matching analysis on each suspected secondary echo region. Specifically, the matching analysis is performed as follows: (1) Identify the suspected secondary echo area Relative azimuth angle in the X-band radar polar coordinate system and center distance Where i∈N, and N is the set of possible cases R. x The total number of suspected secondary echo areas in the middle; (2) Set S of strong echo targets c Mapped to the suspected secondary echo region Within the polar coordinate system centered on the X-band radar, this represents the set of strong echo targets after mapping. ; (3) Use spatial logic matching strategy to identify suspected secondary echo areas and the mapped set of strong echo targets Perform a search and match to obtain the judgment result; (4) Determine whether to include the suspected secondary echo area based on the judgment result. Add to the confirmation set.

4. The method for identifying and eliminating X-band radar secondary echo networks according to claim 3, characterized in that, In (3), the spatial logical matching strategy for search matching is specifically as follows: ① Determine the set of targets with strong echoes Check if it is empty; if so, the result is negative. Conversely, proceed to step ②; ②Analyze each strong echo region after mapping With suspected secondary echo area If the relative positions between them are within a preset range, then the result is negative. Conversely, proceed to ③; ③ Determine the area mapped to the corresponding X-band radar strong echo region. Distance and suspected secondary echo area Does the true distance R after de-ambiguation exceed the distance threshold? If not, the result is confirmed; otherwise, the result is denied. Range ambiguity corresponds to the echo signal received by the X-band radar actually being generated by the previous one or several transmitted pulses. The true distance R after de-ambiguation is expressed as: Where m represents the number of blurring operations; c is the speed of light; PRF is the pulse repetition frequency of a radar scan; This is the display distance of the X-band radar corresponding to the suspected secondary echo distance.

5. An X-band radar secondary echo identification and rejection system, used to implement the X-band radar secondary echo network identification and rejection method as described in any one of claims 1-4, characterized in that, include: Data acquisition module; The acquisition module is used to acquire S-band, C-band, and X-band weather radar base data for the target area; Preprocessing module; The preprocessing module is used to filter and remove ground clutter from S-band, C-band, and X-band weather radar base data; The feature initial judgment module and the feature extraction module are used to identify features in the preprocessed X-band radar data and extract all suspected secondary echo regions to form a suspected set R. x ; Target extraction module; the target extraction module is used to extract all strong echo regions from the preprocessed mosaic, forming a set of strong echo targets S. c ; Spatial logical matching decision module; the spatial logical matching decision module performs a selection of the suspected set R. x Each suspected secondary echo region and the set of strong echo targets S c The spatial logic matching strategy is used to perform matching analysis and obtain the analysis results; Quality control execution and output module: The quality control execution and output module performs elimination processing on the X-band radar base data based on the analysis results, and obtains and outputs the eliminated X-band radar data.

6. An X-band radar secondary echo identification and rejection device, characterized in that, include: Storage; Storage is used to store computer programs; Actuator; The actuator is used to execute a computer program stored in the memory, which, when executed, implements the X-band radar secondary echo network identification and elimination method as described in any one of claims 1-4.

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