A method to improve the effectiveness of secondary radar interleaving target codes in complex environments

Abstract

This invention discloses a method for improving the effectiveness of interleaved target codes in complex environments. The method involves correcting target codes in both raw response data and historical target data, including: S1: Point interleaving processing; wherein, point interleaving processing includes: S11: Raw point reception, S12: Finding interleaved responses, S13: Point code processing; S2: Point code correction steps; wherein, point code correction includes: S21: Finding historical points, S22: Historical information extraction, and S23: Code information correction. This invention utilizes the response characteristics of target response information and the historical code information of the target for point interleaving processing and point code correction, which can greatly improve the decoding accuracy of point codes and enhance the target detection quality of secondary radar.

Description

Technical Field

[0001] This invention belongs to the field of secondary radar technology, and in particular relates to a method for improving the effectiveness of interleaved target codes in complex environments. Background Technology

[0002] Secondary radar systems are widely used in air traffic control in both military and civil aviation, providing assurance for the aviation safety of aircraft.

[0003] Secondary radar primarily identifies aerial targets using secondary target codes. These codes consist of multiple response pulses in the response signal. When a secondary target appears in complex geographical, electromagnetic, or airspace environments, the target's response information may overlap or become distorted. This causes the pulses corresponding to the secondary target's response code to be interleaved and interfered with, making it impossible to correctly identify the code information in the response signal. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems of the prior art and disclose a method to improve the effectiveness of interleaved target codes in complex environments. This invention utilizes the response characteristics of target response information and the historical code information of the target for point interleaving processing and point code correction, which can greatly improve the decoding accuracy of point codes and enhance the target detection quality of secondary radar.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A method for improving the effectiveness of target codes in secondary radar interleaving under complex environments, wherein the method involves correcting target codes in both raw response data and historical target data, including:

[0007] S1: Dot interlacing processing;

[0008] The dot interleaving process includes: S11: receiving the original dot, S12: finding the interleaving response, and S13: processing the dot code.

[0009] S2: Steps for correcting dot code;

[0010] The point code correction includes: S21: finding historical points, S22: extracting historical information, and S23: correcting code information.

[0011] According to a preferred embodiment, S11: Receiving the original dot pattern includes the following steps:

[0012] S111: Obtain the target's original trace data, perform a validity check on the target message frame, and discard the data if it is invalid;

[0013] S112: Determine the distance information of the original point data. If the distance exceeds the set range, the data is considered invalid and discarded.

[0014] S113: Determine the orientation information of the original point data. If it exceeds the orientation setting range, the data is considered invalid and discarded.

[0015] S114: Filter according to the target's response pattern and store the data of each target into the corresponding pattern database.

[0016] According to a preferred embodiment, in step S114, when the original point data is stored in the database, it is stored in ascending order according to the distance and orientation of the target.

[0017] According to a preferred embodiment, S12: Searching for interleaved responses includes:

[0018] S121: Traverse the pattern database, traversing all surviving original point data;

[0019] S122: If the distance difference between two original point data is outside the distance-related threshold, continue to step S121 to traverse the remaining data;

[0020] S123: If the azimuth difference between two original point data is outside the relevant threshold, continue to step S121 to traverse the remaining data;

[0021] S124: For cases where both distance difference and orientation are within the relevant thresholds, perform interweaving identification judgment;

[0022] S125: If the front frame pulse F1 has interleaving information and the rear frame pulse F2 does not have interleaving information, then mark the front interleaving indicator.

[0023] S126: If the front frame pulse F1 has interleaving information and the rear frame pulse F2 has interleaving information, then mark it as fully interleaved.

[0024] S127: If the front frame pulse F1 has no interleaving information and the rear frame pulse F2 has interleaving information, then mark the rear interleaving indicator.

[0025] S128: If the front frame pulse F1 has no interleaving information and the rear frame pulse F2 has no interleaving information, then mark it with a no-interleaving flag.

[0026] According to a preferred embodiment, S13: Interlacing dot processing includes:

[0027] S131: Extract data from the pattern database and compare it with the corresponding original point response data;

[0028] S132: Perform distance-related judgment. If the distance difference is outside the distance-related threshold, continue to step S131 to traverse the remaining data.

[0029] S133: Perform orientation-related judgment. If the orientation difference is outside the relevant threshold, continue to step S131 to traverse the remaining data.

[0030] S134: When the data extracted from the pattern database and all the original trace response data have been traversed, a trace node is generated, which contains all the successful original response data information related to the data extracted from the pattern database.

[0031] S135: Determine whether the number of original trace response data in the trace node exceeds the maximum threshold value.

[0032] If the value exceeds the limit, interleaving processing begins; if the value does not exceed the limit, it is determined whether the difference between the azimuth value of the last packet of original point response data and the current implementation azimuth exceeds the maximum threshold. If the value does not exceed the limit, step S131 is continued to re-traverse the remaining data; if the value exceeds the limit, interleaving processing begins.

[0033] S136: Perform code processing on the dots. Based on the code values ​​in all the original dots response data, extract the top five code values ​​that appear most frequently, and obtain the count of the interleaving marker in the corresponding original dots response.

[0034] S137: Get the most frequently occurring non-interlaced code value and assign it to the code of the dot;

[0035] S138: If the first five code values ​​are all interleaved, calculate the difference between their number of interleavings and the number of code occurrences, i.e. the number of non-interleaved codes, and take out the code value with the most non-interleaved codes and assign it to the code of the dot.

[0036] S139: If there are no cases where the number of interleaving codes is the same, the corresponding code values ​​are extracted in the order of pre-interleaving, post-interleaving, and full interleaving, and then assigned to the code of the dot.

[0037] S140: Place the processed dot data into the dot database.

[0038] According to a preferred embodiment, S21: Searching for historical traces includes:

[0039] S211: Traverse the point database and perform historical point queries;

[0040] S212: Perform distance judgment. The difference between the current distance and the predicted distance of the historical trace data is scored. If the correlation score is 0, continue to step S211 to query the historical trace.

[0041] S213: Perform orientation determination. The difference between the current location of the point and the predicted location of the historical point data is scored. If the correlation score is 0, continue to step S211 to query the historical point data.

[0042] S214: Store the relevant historical point information with a score that is not 0 in the point queue for subsequent correction operations.

[0043] According to a preferred embodiment, S22: Historical information extraction includes:

[0044] S221: Extract relevant successful historical trace information from the trace queue, and take the 3 sets of historical trace data with the highest relevant scores;

[0045] S222: Traverse these 3 sets of historical point data. If only one set of historical point data has the same code as the point code, extract the information of that historical point data for information extraction.

[0046] S223: If there are more than one set of historical trace data with the same code as the trace code, then extract the historical trace data information with the highest relevant score for information extraction.

[0047] S224: If there is no historical trace data with the same code as the trace code, then extract the historical trace data information with the highest relevant score for information extraction;

[0048] According to a preferred embodiment, in the historical information extraction step S22, when extracting information, it is necessary to extract the historical trace code, historical trace amplitude information, historical trace interleaving identifier, and historical trace identifier count information, and store them in the trace code correction database.

[0049] According to a preferred embodiment, S23: Code information correction includes:

[0050] S231: If the dot code is an emergency code, then keep the current dot code and do not perform subsequent code information correction operations;

[0051] S232: If the dot code is not a response code, then it is compared with historical dot information in the correction database;

[0052] S233: If the dot code is the same as the code of the current historical dot information in the most recent 6 frames of data, then the dot code remains unchanged;

[0053] S234: If the code of the dot pattern is different from the code of the current historical dot pattern in the last 6 frames of data, then determine the interleaving identifier corresponding to each code, and assign the code that appears most frequently among the codes without interleaving identifiers to the dot pattern code.

[0054] S235: If the code of the dot pattern is different from the code of the current historical dot pattern in the last 6 frames of data, and each code has an interleaving indicator, then the code of the historical dot pattern is assigned to the code.

[0055] S236: Store the corrected code in the code of the historical point for subsequent code information correction operations of the point.

[0056] The aforementioned main solution of the present invention and its various further alternative solutions can be freely combined to form multiple solutions, all of which are solutions that can be adopted and are claimed by the present invention. Those skilled in the art, after understanding the solution of the present invention, will realize that there are many combinations based on existing technology and common knowledge, all of which are technical solutions to be protected by the present invention, and will not be exhaustively listed here.

[0057] The beneficial effects of this invention are:

[0058] This invention provides a method to improve the effectiveness of interleaved target codes in complex environments, involving interleaving and code correction of raw target data. Secondary radar codes are identified by multiple sets of code pulses within the response signal framework; these pulses are extracted and processed to obtain the codewords. When secondary targets appear in complex geographical, electromagnetic, or airspace environments, the target's response information may overlap or become distorted, causing interleaving interference on the pulses corresponding to the secondary target's response code, making it impossible to correctly identify the code information in the response signal. This patent utilizes the response characteristics of the target's response information and the target's historical code information for interleaving and code correction, significantly improving the decoding accuracy of the target codes, enhancing the detection quality of secondary radar, and noticeably improving the stability of secondary target tracks and the accuracy of target information. Attached Figure Description

[0059] Figure 1 This is a schematic diagram of the processing flow of the method for improving the effectiveness of secondary radar interleaving target codes in complex environments according to the present invention. Detailed Implementation

[0060] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0061] It should be noted that similar reference numerals 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. Furthermore, it should be pointed out that unless otherwise specified, the structures, connections, positional relationships, power source relationships, etc., involved in this invention are all things that those skilled in the art can discover without creative effort based on existing technology.

[0062] Example 1

[0063] refer to Figure 1 As shown in the figure, a method for improving the effectiveness of target codes in secondary radar interleaving under complex environments is illustrated. This method involves correcting the target codes of both the original response data and historical target data, including:

[0064] S1: Dot interlacing processing;

[0065] The dot interleaving process includes: S11: receiving the original dot, S12: finding the interleaving response, and S13: processing the dot code.

[0066] S2: Steps for correcting dot code;

[0067] The point code correction includes: S21: finding historical points, S22: extracting historical information, and S23: correcting code information.

[0068] Specifically, the dot code processing flow is as follows:

[0069] I. Reception of Original Dots

[0070] 1. Obtain the original target data and determine the validity of the target message frame. If invalid, discard the data.

[0071] 2. The distance information of the original point data is judged. If it exceeds the distance setting range (default 0~250NM), the data is considered invalid and the data is discarded.

[0072] 3. Determine the orientation information of the original point data. If it exceeds the orientation setting range (default 0~360°), the data is considered invalid and discarded.

[0073] 4. Filter according to the target response pattern and store the target data of MA into the MA pattern database respectively;

[0074] 5. When storing the original point data into the database, it is sorted in ascending order according to the distance and orientation of the target.

[0075] II. Finding Intertwined Responses

[0076] 1. Traverse the pattern database, iterating through all surviving original point data;

[0077] 2. If the distance difference between two original point data is outside the distance threshold (default 150m), then continue to step 1 to traverse the remaining data;

[0078] 3. If the azimuth difference between two original point data is outside the relevant threshold (the default value is 3dB beamwidth of the current device), then continue to step 1 to traverse the remaining data;

[0079] 4. For cases where both distance difference and orientation are within the relevant thresholds, interlacing identification is performed;

[0080] 5. If the front frame pulse F1 has interleaving information and the rear frame pulse F2 does not have interleaving information, then mark it with a front interleaving indicator;

[0081] 6. If the front frame pulse F1 has interleaving information and the rear frame pulse F2 has interleaving information, then mark it as fully interleaved;

[0082] 7. If the front frame pulse F1 has no interleaving information, but the rear frame pulse F2 has interleaving information, then mark it with a rear interleaving indicator.

[0083] 8. If the front frame pulse F1 has no interleaving information and the rear frame pulse F2 has no interleaving information, then mark it with a no-interleaving flag.

[0084] III. Processing of Interlaced Dots

[0085] 1. Extract data from the pattern database and compare it with the subsequent original point response data;

[0086] 2. Perform distance-related judgment. If the distance difference is outside the distance-related threshold (default 60m), continue to step 1 to traverse the remaining data.

[0087] 3. Perform azimuth correlation judgment. If the azimuth difference is outside the relevant threshold (the default value is 3dB beamwidth of the current device * 1.5), then continue to step 1 to traverse the remaining data.

[0088] 4. Once all original trace response data has been traversed, a trace node is generated, which contains all related successful original response data information;

[0089] 5. Determine whether the number of original trace response data in the trace node exceeds the maximum threshold (default 180 times). If it does, start interleaving. If it does not exceed the threshold, determine whether the difference between the azimuth value of the last packet of original trace response data and the current implementation azimuth exceeds the maximum threshold (default value is 3dB beamwidth of the current device * 2). If it does not exceed the threshold, continue step 1 to re-traverse the remaining data. If it exceeds the threshold, start interleaving.

[0090] 6. Perform code processing on the traces. Based on the code values ​​in all the original trace response data, extract the top five code values ​​that appear most frequently, and obtain the count of the interleaving marker in the corresponding original trace response.

[0091] 7. Obtain the non-interlaced code value with the highest frequency and assign it to the code of the dot pattern;

[0092] 8. If the first five code values ​​are intertwined, calculate the difference between the number of intertwines and the number of code occurrences, i.e. the number of non-intertwined codes. Take the code value with the most non-intertwined codes and assign it to the code of the dot.

[0093] 9. If the number of interleaving codes is the same, the corresponding code values ​​are extracted in the order of pre-interleaving, post-interleaving, and full interleaving, and then assigned to the code of the dot.

[0094] 10. Place the processed dot data into the dot database.

[0095] The process for correcting dot marks is as follows:

[0096] I. Locating Historical Traces

[0097] 1. Traverse the trace database and perform historical trace queries;

[0098] 2. Perform distance judgment. Score the difference between the current distance to the current point and the predicted distance of the historical point data. If the correlation score is 0, continue to step 1 to query the historical points.

[0099] 3. Perform orientation determination. Score the difference between the current location and the predicted location of the historical location data. If the correlation score is 0, continue to step 1 to query the historical location data.

[0100] 4. The distance and orientation related criteria are shown in the table below.

[0101] Table 1 Distance and Direction Criteria

[0102]

[0103] 5. Store the relevant historical trace information with scores that are not 0 in the trace queue for subsequent correction operations.

[0104] II. Historical Information Extraction

[0105] 1. Extract relevant successful historical trace information from the trace queue, and take the 3 sets of historical trace data with the highest relevant scores;

[0106] 2. Iterate through these 3 sets of historical point data. If only one set of historical point data has the same code as the point code, then extract the information of that historical point data for information extraction.

[0107] 3. If more than one set of historical trace data has the same code as the trace code, then extract the historical trace data information with the highest relevant score for information extraction.

[0108] 4. If there is no historical trace data with the same code as the trace code, then extract the historical trace data with the highest relevant score for information extraction.

[0109] 5. When extracting information, it is necessary to extract various information such as historical trace codes, historical trace amplitude information, historical trace interleaving indicators, and historical trace indicator counts, and store them in the trace code correction database.

[0110] III. Code Information Correction

[0111] 1. If the dot code is an emergency code (such as 1255, 1277, 2000, 7500, 7600, 7700), then keep the current dot code and do not perform subsequent code information correction operations;

[0112] 2. If the dot code is not a response code, then it is compared with historical dot information in the correction database;

[0113] 3. If the dot code is the same as the code of the current historical dot information in the most recent 6 frames of data, then the dot code remains unchanged;

[0114] 4. If the code of the dot pattern is different from the code of the current historical dot pattern in the last 6 frames of data, then determine the interleaving identifier corresponding to each code, and assign the code that appears most frequently among the codes without interleaving identifiers to the dot pattern code.

[0115] 5. If the code of the dot pattern is different from the code of the current historical dot pattern in the last 6 frames of data, and each code has an interleaving indicator, then the code of the historical dot pattern is assigned to the code.

[0116] 6. Save the corrected code into the code of the historical points, and use the code information of subsequent points to perform error correction operations.

[0117] This completes the point-track code error correction process. The method of this invention can effectively improve the effectiveness of interleaved target codes in complex environments, increase the code detection probability during secondary radar air detection, and provide more effective code information for subsequent point-track correlation and other algorithmic operations in secondary radar target track processing.

[0118] This invention provides a method to improve the effectiveness of interleaved target codes in complex environments, involving interleaving and code correction of raw target data. Secondary radar codes are identified by multiple sets of code pulses within the response signal framework; these pulses are extracted and processed to obtain the codewords. When secondary targets appear in complex geographical, electromagnetic, or airspace environments, the target's response information may overlap or become distorted, causing interleaving interference on the pulses corresponding to the secondary target's response code, making it impossible to correctly identify the code information in the response signal. This patent utilizes the response characteristics of the target's response information and the target's historical code information for interleaving and code correction, significantly improving the decoding accuracy of the target codes, enhancing the detection quality of secondary radar, and noticeably improving the stability of secondary target tracks and the accuracy of target information.

[0119] 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, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for improving the effectiveness of secondary radar interleaving target codes in complex environments, characterized in that, The method for improving the effectiveness of secondary radar interleaving target codes in complex environments involves correcting target codes in both the original response data and historical target data, including: S1: Dot interleaving processing; The dot interleaving process includes: S11: receiving the original dot, S12: finding the interleaving response, and S13: processing the dot code. S2: Steps for correcting dot code; Among them, the point code correction includes: S21: finding historical points, S22: extracting historical information and S23: correcting code information; S13: Interleaved dot processing includes: S131: Extract data from the pattern database and compare it with the corresponding original point response data; S132: Perform distance-related judgment. If the distance difference is outside the distance-related threshold, continue to step S131 to traverse the remaining data. S133: Perform orientation-related judgment. If the orientation difference is outside the relevant threshold, continue to step S131 to traverse the remaining data. S134: When the data extracted from the pattern database and all the original trace response data have been traversed, a trace node is generated, which contains all the successful original response data information related to the data extracted from the pattern database. S135: Determine whether the number of original trace response data in the trace node exceeds the maximum threshold value. If the value exceeds the limit, interleaving processing begins; if the value does not exceed the limit, it is determined whether the difference between the azimuth value of the last packet of original point response data and the current implementation azimuth exceeds the maximum threshold. If the value does not exceed the limit, step S131 is continued to re-traverse the remaining data; if the value exceeds the limit, interleaving processing begins. S136: Perform code processing on the dots. Based on the code values ​​in all the original dots response data, extract the top five code values ​​that appear most frequently, and obtain the count of the interleaving marker in the corresponding original dots response. S137: Get the most frequently occurring non-interlaced code value and assign it to the code of the dot; S138: If the first five code values ​​are all interleaved, calculate the difference between their number of interleavings and the number of code occurrences, i.e. the number of non-interleaved codes, and take out the code value with the most non-interleaved codes and assign it to the code of the dot. S139: If there are no cases where the number of interleaving codes is the same, the corresponding code values ​​are extracted in the order of pre-interleaving, post-interleaving, and full interleaving, and then assigned to the code of the dot. S140: Place the processed dot data into the dot database.

2. The method for improving the effectiveness of secondary radar interleaving target codes in complex environments as described in claim 1, characterized in that, S11: Receiving the raw dot pattern includes the following steps: S111: Obtain the target's original trace data, perform a validity check on the target message frame, and discard the data if it is invalid; S112: Determine the distance information of the original point data. If the distance exceeds the set range, the data is considered invalid and discarded. S113: Determine the orientation information of the original point data. If it exceeds the orientation setting range, the data is considered invalid and discarded. S114: Filter according to the target's response pattern and store the data of each target into the corresponding pattern database.

3. The method for improving the effectiveness of secondary radar interleaving target codes in complex environments as described in claim 2, characterized in that, In step S114, when the original point data is stored in the database, it is sorted and stored in ascending order according to the distance and orientation of the target.

4. The method for improving the effectiveness of secondary radar interleaving target codes in complex environments as described in claim 2, characterized in that, S12: Searching for interleaved responses includes: S121: Traverse the pattern database, traversing all surviving original point data; S122: If the distance difference between two original point data is outside the distance-related threshold, continue to step S121 to traverse the remaining data; S123: If the azimuth difference between two original point data is outside the relevant threshold, continue to step S121 to traverse the remaining data; S124: For cases where both distance difference and orientation are within the relevant thresholds, perform interweaving identification judgment; S125: If the front frame pulse F1 has interleaving information and the rear frame pulse F2 does not have interleaving information, then mark the front interleaving indicator. S126: If the front frame pulse F1 has interleaving information and the rear frame pulse F2 has interleaving information, then mark it as fully interleaved. S127: If the front frame pulse F1 has no interleaving information and the rear frame pulse F2 has interleaving information, then mark the rear interleaving indicator. S128: If the front frame pulse F1 has no interleaving information and the rear frame pulse F2 has no interleaving information, then mark it with a no-interleaving flag.

5. The method for improving the effectiveness of secondary radar interleaving target codes in complex environments as described in claim 4, characterized in that, S21: Searching for historical traces includes: S211: Traverse the point database and perform historical point queries; S212: Perform distance judgment. The difference between the current distance and the predicted distance of the historical trace data is scored. If the correlation score is 0, continue to step S211 to query the historical trace. S213: Perform orientation determination. The difference between the current location of the point and the predicted location of the historical point data is scored. If the correlation score is 0, continue to step S211 to query the historical point data. S214: Store the relevant historical point information with a score that is not 0 in the point queue for subsequent correction operations.

6. The method for improving the effectiveness of secondary radar interleaving target codes in complex environments as described in claim 5, characterized in that, S22: Historical information extraction includes: S221: Extract relevant successful historical trace information from the trace queue, and take the 3 sets of historical trace data with the highest relevant scores; S222: Traverse these 3 sets of historical point data. If only one set of historical point data has the same code as the point code, extract the information of that historical point data for information extraction. S223: If there are more than one set of historical trace data with the same code as the trace code, then extract the historical trace data information with the highest relevant score for information extraction. S224: If there is no historical trace data with the same code as the trace code, then extract the historical trace data information with the highest relevant score for information extraction.

7. The method for improving the effectiveness of secondary radar interleaving target codes in complex environments as described in claim 6, characterized in that, S22: In the historical information extraction step, when extracting information, it is necessary to extract the historical trace code, historical trace amplitude information, historical trace interleaving identifier, and historical trace identifier count information, and store them in the trace code correction database.

8. The method for improving the effectiveness of secondary radar interleaving target codes in complex environments as described in claim 6, characterized in that, S23: Code information correction includes: S231: If the dot code is an emergency code, then keep the current dot code and do not perform subsequent code information correction operations; S232: If the dot code is not a response code, then it is compared with historical dot information in the correction database; S233: If the dot code is the same as the code of the current historical dot information in the most recent 6 frames of data, then the dot code remains unchanged; S234: If the code of the dot pattern is different from the code of the current historical dot pattern in the last 6 frames of data, then determine the interleaving identifier corresponding to each code, and assign the code that appears most frequently among the codes without interleaving identifiers to the dot pattern code. S235: If the code of the dot pattern is different from the code of the current historical dot pattern in the last 6 frames of data, and each code has an interleaving indicator, then the code of the historical dot pattern is assigned to the code. S236: Store the corrected code in the code of the historical point for subsequent code information correction operations of the point.

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