Distance-Doppler-based two-dimensional space target pairing method

Abstract

The invention discloses a two-dimensional space target pairing method based on distance-Doppler, and the method comprises the following steps: obtaining distance-Doppler data generated by different paths when distributed radars transmit and receive radar signals mutually, the distance-Doppler data comprising path features, distance units, amplitudes and Doppler values; wherein the path characteristics comprise a sending radar number R1 and a receiving radar number R2; preprocessing the distance-Doppler data, identifying path types, and generating a pairing data set; determining a two-dimensional pairing condition, wherein the two-dimensional pairing condition comprises a distance threshold and a Doppler threshold; and traversing the pairing data set, and generating a pairing result data set according to the two-dimensional pairing condition. According to the technical scheme, screening can be carried out through the pairing algorithm based on the distance and Doppler relation between the target and the site due to the spatial position, the accuracy of successful pairing of the real target is improved, and the false alarm rate is reduced.

Description

Technical Field

[0001] The present invention relates to the field of radar communication technology, and in particular to a two-dimensional space target pairing method based on range-Doppler. Background Art

[0002] With the continuous development of radar technology, various new radar systems are constantly emerging, among which MIMO radar system is more representative. MIMO radar can be divided into two types in terms of system: centralized and distributed. Distributed radar consists of a network of multiple radar sites in different locations but working together. Through network connection and collaborative work, the limitation of a single radar at a single angle is broken through, and high-precision, all-round monitoring and tracking of the target is achieved. In general, the signal waveforms emitted by this radar need to have good orthogonal characteristics so that the radar can determine the source of the signal when receiving it. When the distributed radar is in a multi-transmit and multi-receive state, the same target will generate echoes on different paths. Therefore, it is necessary to perform target space pairing on multiple paths to achieve fusion detection of distributed radar. Target space pairing is a traditional and challenging problem in distributed radar signal processing. When the distributed radar performs centralized joint detection of the target, each path can be separated by using traditional signal processing methods such as orthogonal signals, but the information generated by the real target in each path is mixed with the information generated by noise clutter. It is impossible to determine which one is the true target information, nor can it be found which real target information corresponds to the same target. In the existing technology, most pairing schemes only use distance information. For MIMO radar, especially distributed radar fusion detection technology, the key is to extract the information of the same target on different radar paths, and then perform angle measurement, coordinate determination, track tracking and other operations. Starting from the positional relationship between the distributed radar and the target, the relationship between the distance and Doppler shift of the echo information generated by the same target on different paths can be explored. Therefore, when the target moves, there is other information in the echo formed on different paths, such as Doppler, which is also of great significance to the joint detection of signals.

[0003] Therefore, a range-Doppler two-dimensional space pairing method that combines the information of range and Doppler is needed. Summary of the invention

[0004] To achieve the above object, the present application provides a two-dimensional space target pairing method based on range-Doppler, comprising the following steps:

[0005] Acquire the range-Doppler data generated by different paths when the distributed radars mutually transmit and receive radar signals, wherein the range-Doppler data includes: path characteristics, distance units, amplitudes, and Doppler values; wherein the path characteristics include the transmitting radar number R1 and the receiving radar number R2;

[0006] Preprocessing the range-Doppler data, identifying the path type, and generating a paired data set; the path type includes: self-path and other-path, the self-path refers to the path data with the same sending radar number and the receiving radar number, and the other-path refers to the path data with different sending radar numbers and the receiving radar numbers;

[0007] Determine a two-dimensional pairing condition, the two-dimensional pairing condition includes: a distance threshold and a Doppler threshold;

[0008] Traverse the pairing data set and generate a pairing result data set based on the two-dimensional pairing conditions.

[0009] Among them, the judgment method of distance threshold determination is:

[0010] and in, is the delay of sending radar self-path, is the delay of the receiving radar self-path, is the time delay of the path between the sending radar and the receiving radar, ε1 is the distance threshold;

[0011] The determination method of Doppler threshold is:

[0012] in, To send the radar self-path Doppler value, is the self-path Doppler value of the receiving radar, is the time delay of the path between the sending radar and the receiving radar, and ε2 is the Doppler threshold.

[0013] Furthermore, the preprocessing includes:

[0014] Exclude data from its path that does not correspond to a round trip;

[0015] The range-Doppler data is stored in the distance matrix A, represented as A = [x1 x2...x j ] T , and: x j =[T,R1,R2,D,A,F], where j is the path number and j<the total number of paths, T is the path type, R1 is the sending radar number, R2 is the receiving radar number, D is the path distance unit, A is the amplitude, and F is the Doppler value.

[0016] Further, traversing the pairing data set and generating a pairing result data set according to the two-dimensional pairing condition includes:

[0017] extracting a path from the paired data set;

[0018] Acquire a radar pair from the self-path, the radar pair comprising a first radar and a second radar;

[0019] It is determined whether the other paths formed by the radar pair meet the two-dimensional pairing condition, wherein the other paths formed by the radar pair include: the self-path of R1, the self-path of R2, and the other paths of R1 and R2.

[0020] Among them, judging whether the paths formed by the radar pair meet the two-dimensional pairing conditions includes:

[0021] Extract its path from the paired data set;

[0022] Extracting a radar-to-it path from the it path, wherein the radar-to-it path refers to an it path in which the sending radar number and the receiving radar number correspond to the first radar and the second radar;

[0023] Determine the three-party path, determine whether the three-party path meets the distance threshold determination, and if so, add the three-party path to the result data set;

[0024] The three-way path refers to: the self-path of the first radar, the self-path of the second radar and the radar-to-other path.

[0025] Specifically, the method of traversing the pairing data set and generating a pairing result data set according to the two-dimensional pairing condition includes the following steps:

[0026] Define the path storage matrix Y, expressed as Y = [y1 y2...y k ] T , where y k is the radar path dataset, denoted as y k =[R1, R2, DATA1, DATA2, DATA]; where k is the radar pair number, DATA1 is the path data matrix of the radar R1, expressed as: DATA1 = [m1 m2 ... m a ] T , where m a is the detection data of the ath group of the self-path of R1, expressed as m a =[j,D,A,F], where a is the detection data number of the self-path of the radar R1, which is less than or equal to the number of self-path detection data of the radar R1;

[0027] DATA2 is the path data matrix of the radar R2, expressed as: DATA2 = [n1 n2 ... n b ] T , where n b is the detection data of the bth group of self-paths of R2, expressed as n b =[j, D, A, F], b is the detection data number of the self-path of the radar R2, which is less than or equal to the number of self-path detection data of the radar R2;

[0028] DATA is the path data matrix of radar R1 and R2, expressed as: DATA = [o1 o2 ... o c ] T , where o c It is the detection data of its path, represented by o c =[j,D,A,F], c is the detection data number of its path, which is less than or equal to the number of detection data of its path;

[0029] Extract data from the distance matrix A and store it in the path storage matrix Y;

[0030] Traverse the path storage matrix Y and output the result data set.

[0031] Further, traversing the path storage matrix Y to output a result data set includes the following steps:

[0032] Step S1: Initialize parameters, define k=1, a=1, b=1, c=1, and execute step S2;

[0033] Step S2: Extract radar pair array y from Y k , execute step S3;

[0034] Step S3: Extract the radar pair array y k m a 、n b , execute step S4;

[0035] Step S4: According to R1 and R2, k Extract it path o c , execute step S5;

[0036] Step S5: Determine m a 、n b , o c Whether it meets the distance threshold, if it does, m a 、n b , o c After adding the result data set, execute step S6;

[0037] Step S6: define c=c+1, determine o c Does it exist? If so, go to step S4; otherwise, go to step S7;

[0038] Step S7: define b=b+1, c=1, and determine n b Does it exist? If so, go to step S3; otherwise, go to step S9;

[0039] Step S9: define a=a+1, b=1, c=1, and determine m aDoes it exist? If so, go to step S3; otherwise, go to step S10;

[0040] Step S10: define k=k+1, a=1, b=1, c=1, and determine y k Does it exist? If so, execute step S2; otherwise, output the result data set.

[0041] When extracting data from the distance matrix A and storing it in the path storage matrix Y, the self-path data and other-path data of R1 and R2 are judged, and if the pairing conditions are met, they are stored;

[0042] The judgment condition is expressed as: the distance of the round trip path is consistent with the Doppler information, expressed as:

[0043]

[0044] Among them, ε1 is the distance threshold, and ε2 is the Doppler threshold.

[0045] According to the present invention, based on the original distance information, the Doppler relationship of the target in different paths is combined, a stricter judgment standard is possessed, fewer false targets are screened out by the algorithm, and the pairing accuracy is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is a step diagram of a two-dimensional space target pairing method provided according to an embodiment of the present invention;

[0047] Figure 2 is a step diagram of a method for generating a pairing result data set provided in an embodiment of the present invention;

[0048] Figure 3 is a comparison chart of the success rates of two-dimensional space target pairing and one-dimensional pairing simulation experiments provided according to an embodiment of the present invention;

[0049] Figure 4 It is a comparison chart of false alarm rates in a two-dimensional space target pairing and one-dimensional pairing simulation experiment provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0050] When multiple radars detect one or more targets, the separated multipath information contains real target information and false target information, which are mixed and cannot be separated. The solution proposed by the present invention uses the spatial position information of the radar base station and the target, and uses the two-dimensional information mapped on the distance and Doppler to perform pairing and separation, and extract the real target information, eliminate the false target information, and combine the corresponding information of the target on each path, so as to restore the coordinate position in combination with the angle measurement later.

[0051] The specific implementation of the present invention is described in detail below with reference to the accompanying drawings.

[0052] Figure 1 The present invention provides a two-dimensional space target pairing method based on range-Doppler, comprising:

[0053] Step S100: acquiring range-Doppler data generated by different paths when distributed radars mutually transmit and receive radar signals, the range-Doppler data including: path characteristics, distance units, amplitudes and Doppler values; wherein the path characteristics include a transmitting radar number R1 and a receiving radar number R2;

[0054] During the acquisition process, distributed radars send and receive radar signals to each other to detect targets, perform conventional signal processing such as MTD, and obtain the reception data of each station.

[0055] Step S110: pre-processing the range-Doppler data, identifying the path type, and generating a paired data set; wherein the path type includes: self-path and other-path;

[0056] Self-path refers to the path data with the same sending radar number and receiving radar number, for example: radar 1-target-radar 1;

[0057] It path refers to the path data with different sending radar numbers and receiving radar numbers, for example: Radar 1-target-Radar 2; the two-way sending and receiving path between two radars is called a round-trip it path, such as Radar 1-target-Radar 2 and Radar 2-target-Radar 1.

[0058] For the same target, the target echo distance and Doppler information obtained according to the round-trip paths (such as radar 1-target-radar 2 and radar 2-target-radar 1) should be the same. Therefore, in the preprocessing process performed in this step, after identifying the path type, it is determined whether there is corresponding data in the separated path that appears in the round-trip path, the corresponding data is retained and arranged in pairs, and the data that cannot be found to correspond to the round-trip is excluded, that is, the data that does not belong to the round-trip correspondence is excluded.

[0059] Afterwards, the path data that does not correspond to the round trip is cleared and stored.

[0060] Specifically, the range-Doppler data is stored in the distance matrix A, which is expressed as A = [x1 x2 ... x j ] T , and: x j is the specific data set of the path, represented by x j =[T,R1,R2,D,A,F], where j is the path number and j<the total number of paths, T is the path type, R1 is the sending radar number, R2 is the receiving radar number, D is the path distance unit, A is the amplitude, and F is the Doppler value.

[0061] Step S101: determining a two-dimensional pairing condition, wherein the two-dimensional pairing condition includes: a distance threshold and a Doppler threshold;

[0062] Specifically: The distance threshold determination method is:

[0063] and

[0064] in, is the delay of sending radar self-path (such as radar 1-n-radar 1 path), is the delay of the receiving radar self-path, is the time delay of the path between the sending radar and the receiving radar (sending radar 1-radar 2), and ε1 is the distance threshold. When making distance threshold judgment, the time delay and path distance unit are converted: the time delay is equal to twice the distance divided by the speed of light, and the path distance unit is a discrete distance.

[0065] The determination method of Doppler threshold is:

[0066]

[0067] in, is the self-path Doppler value of the sending radar, fa n b is the self-path Doppler value of the receiving radar, fb n a is the time delay of the path between the sending radar and the receiving radar, and ε2 is the Doppler threshold.

[0068] Step S120: traverse the pairing data set and generate a pairing result data set according to the two-dimensional pairing condition.

[0069] The process includes the following steps:

[0070] Extracting self-paths from paired data sets;

[0071] Acquire a radar pair from the self-path, the radar pair comprising a first radar and a second radar, such as the self-path of R1 and the self-path of R2;

[0072] It is determined whether the other paths formed by the radar pair meet the two-dimensional pairing condition. The other paths formed by the radar pair include: the self-path of R1, the self-path of R2, and the other paths of R1 and R2.

[0073] The specific process of determining whether the path formed by the radar pair meets the two-dimensional pairing condition includes the following steps:

[0074] 1) Extract its path from the paired data set;

[0075] 2) extracting a radar-to-other path from the other path, wherein the radar-to-other path refers to the other path of the first radar and the second radar corresponding to the sending radar number and the receiving radar number;

[0076] 3) Determine a three-party path, where the three-party path refers to: the self-path of the first radar, the self-path of the second radar, and the other path of the radar.

[0077] 4) Determine whether the data of the three-party path meets the distance threshold judgment. If yes, add the data of the three-party path to the result data set;

[0078] The implementation method of this step includes the following contents:

[0079] 1) Define the path storage matrix Y, expressed as Y = [y1 y2 ... y k ] T , where y k is the radar path dataset, denoted as y k =[R1, R2, DATA1, DATA2, DATA]; where k is the radar pair number, DATA1 is the self-path data matrix of the radar R1, expressed as: DATA1 = [m1 m2 ... m a ] T , where m a is the detection data of the ath group of the self-path of R1, expressed as m a =[j,D,A,F], a is the detection data number of the self-path of the radar R1, which is less than or equal to the number of self-path detection data of the radar R1; the self-path detection data contained in the radar R1 is in m a In the descending order of amplitude A;

[0080] For example, m1 = [10, 200, 0.8, 5], m2 = [10, 260, 0.6, 8] respectively represent two sets of detection data with path number 10 in the self-path of radar R1;

[0081] DATA2 is the self-path data matrix of the radar R2, expressed as: DATA2 = [n1 n2 ... n b ] T , where n b is the detection data of the bth group of self-paths of R2, expressed as n b =[j,D,A,F], b is the detection data path number of the radar R2 self-path, which is less than or equal to the number of self-path detection data of the radar R2; the self-path detection data of the radar R2 is n b In the descending order of amplitude A;

[0082] DATA is the path data matrix of radar R1 and R2, expressed as: DATA = [o1 o2 ... o c ] T , where o c It is the detection data of its path, represented by o c =[j,D,A,F], c is the detection data number of its path, which is less than or equal to the number of its paths, and the data of its path is in o c In the figure, they are arranged in descending order of amplitude A.

[0083] After the definition is completed, data is extracted from the distance matrix A and stored in the path storage matrix Y. When extracting, the self-path data and other-path data of R1 and R2 are judged, and if the pairing condition is met, they are stored; the judgment condition is expressed as: the distance to and from the other path is consistent with the Doppler information, expressed as:

[0084]

[0085] At this time, the path information that does not meet this condition is false target information, and part of the false target information is eliminated in this step.

[0086] 2) Determine whether the three-way path meets the distance threshold. This process is as follows: Figure 2 As shown, the following steps are included:

[0087] Step S200, inputting a storage matrix Y;

[0088] Step S210: Load the processing function, the processing function executes step S220 to traverse the storage matrix Y and perform the following operations:

[0089] Step S1: Initialize parameters, define k=1, a=1, b=1, c=1, and execute step S2;

[0090] Step S2: Extract radar pair array y from Y k , execute step S3;

[0091] Step S3: Extract radar pair array y k m a 、n b , execute step S4;

[0092] Step S4: According to R1 and R2, k Extract it path o c , execute step S5;

[0093] Step S5: Determine m a 、n b , o c Whether it meets the distance threshold, if it does, m a 、nb , o c After adding the result data set, execute step S6;

[0094] The present invention also provides a more optimized processing solution, because m a 、n b , o c The data in the result are sorted from large to small according to the amplitude. Therefore, after the result set that meets the conditions is determined, the data with the largest amplitude is obtained. At this time, step S6 does not need to be performed. c The subsequent data is judged and directly enters step S7 to enter the next round of traversal;

[0095] Step S6: define c=c+1, determine o c Does it exist? If so, go to step S4; otherwise, go to step S7;

[0096] Step S7: define b=b+1, c=1, and determine n b Does it exist? If so, go to step S3; otherwise, go to step S9;

[0097] Step S9: define a=a+1, b=1, c=1, and determine m a Does it exist? If so, go to step S3; otherwise, go to step S10;

[0098] Step S10: define k=k+1, a=1, b=1, c=1, and determine y k Does it exist? If so, execute step S2; otherwise, output the result data set.

[0099] The present invention also provides a simulation experiment of simulating four radar platforms to detect two targets: there are self-paths and other-paths between the four radars, and a total of 16 paths are generated. The simulation uses the MTD data after the radar signal is transmitted, received and processed, and the algorithm process of pairing the input distance-Doppler two-dimensional path information. The distance and speed data are converted into the detected distance unit and Doppler channel for calculation. The simulation adopts the Monte Carlo method and repeats the experiment 200 times. The number of successfully paired target points is recorded in each experiment, and the detection probability curve is drawn to verify the detection performance of the spatial registration system.

[0100] In each experiment, the path data of the real target is added with positive and negative random numbers to simulate the error in the detection process, and the error size is increased. The false target is generated by random numbers in random paths, random distance units, and random Doppler channels. After the true and false targets are constructed, the real target will be mixed with the false target data to form the input data of the spatial registration system. The simulation shows that the missed detection rate of the two-dimensional pairing algorithm is higher than that of the one-dimensional algorithm. Figure 3 As shown, the false alarm changes as Figure 4shown.

[0101] The above simulation experiments verify the effectiveness and reliability of this method, which can effectively reduce the possibility of false targets through pairing. On the basis of the original pairing algorithm, it excludes data with correct distance but Doppler errors, thereby enhancing accuracy.

[0102] In summary, the distance-Doppler two-dimensional space pairing method proposed in the present invention solves the multi-path fusion problem in distributed radar detection. Based on the distance and Doppler relationship between the target and the site due to the spatial position, the pairing algorithm is used for screening, thereby improving the accuracy of successful pairing of real targets and reducing false alarms. It has a good effect in distributed radar fusion detection and provides help for subsequent angle measurement positioning, track fusion and other tasks of the distributed radar.

[0103] The above disclosures are only several specific embodiments of the present invention; however, the present invention is not limited thereto, and any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A two-dimensional space target pairing method based on range-Doppler, characterized in that: The following steps are involved: Acquire the range-Doppler data generated by different paths when the distributed radars mutually transmit and receive radar signals, wherein the range-Doppler data includes: path characteristics, distance units, amplitudes, and Doppler values; wherein the path characteristics include the transmitting radar number R1 and the receiving radar number R2; Preprocessing the range-Doppler data, identifying the path type, and generating a paired data set; the path type includes: a self-path and an other-path, the self-path refers to the path data with the same sending radar number and the receiving radar number, and the other-path refers to the path data with different sending radar numbers and the receiving radar numbers; Determining a two-dimensional pairing condition, wherein the two-dimensional pairing condition includes: a distance threshold and a Doppler threshold; The pairing data set is traversed, and a pairing result data set is generated according to the two-dimensional pairing condition.

2. The two-dimensional space target pairing method according to claim 1, characterized in that: The distance threshold determination method is as follows: and in, is the delay of sending radar self-path, is the delay of the receiving radar self-path, is the time delay of the path between the sending radar and the receiving radar, ε1 is the distance threshold; The determination method of the Doppler threshold is: in, To send the radar self-path Doppler value, is the self-path Doppler value of the receiving radar, is the time delay of the path between the sending radar and the receiving radar, and ε2 is the Doppler threshold.

3. The two-dimensional space target pairing method according to claim 1, characterized in that: The pre-processing comprises: Excluding data that does not correspond to a round trip from the other path; The range-Doppler data is stored in the distance matrix A, which is represented by A=[x1x2...x j ] T , and: x j =[T,R1,R2,D,A,F], where j is the path number and j<the total number of paths, T is the path type, R1 is the sending radar number, R2 is the receiving radar number, D is the path distance unit, A is the amplitude, and F is the Doppler value.

4. The two-dimensional space target pairing method according to claim 3, characterized in that: The traversing the pairing data set and generating a pairing result data set according to the two-dimensional pairing condition comprises: extracting a path from the paired data set; Acquire a radar pair from the self-path, the radar pair comprising a first radar and a second radar; It is determined whether the other paths formed by the radar pair meet the two-dimensional pairing condition, wherein the other paths formed by the radar pair include: the self-path of R1, the self-path of R2, and the other paths of R1 and R2.

5. The two-dimensional space target pairing method according to claim 4, characterized in that: The determining whether the other paths formed by the radar pair meet the two-dimensional pairing condition includes: extracting its path from the paired data set; Extracting a radar-to-other path from the other path, wherein the radar-to-other path refers to an other path in which the sending radar number and the receiving radar number correspond to the first radar and the second radar; Determine a three-party path, determine whether the three-party path meets the distance threshold determination, and if so, add the three-party path to the result data set; The three-party paths refer to: the self-path of the first radar, the self-path of the second radar and the radar-to-other path.

6. The two-dimensional space target pairing method according to claim 5, characterized in that: The method of traversing the pairing data set and generating a pairing result data set according to the two-dimensional pairing condition comprises the following steps: Define the path storage matrix Y, expressed as Y = [y1 y2...y k ] T , where y k is the radar path dataset, denoted as y k =[R1, R2, DATA1, DATA2, DATA]; where k is the radar pair number, DATA1 is the path data matrix of the radar R1, expressed as: DATA1 = [m1 m2 ... m a ] T , where m a is the detection data of the ath group of the self-path of R1, expressed as m a =[j,D,A,F], where a is the detection data number of the self-path of the radar R1, which is less than or equal to the number of self-path detection data of the radar R1; DATA2 is the path data matrix of the radar R2, expressed as: DATA2 = [n1 n2 ... n b ] T , where n b is the detection data of the bth group of self-paths of R2, expressed as n b =[j, D, A, F], b is the detection data number of the self-path of the radar R2, which is less than or equal to the number of self-path detection data of the radar R2; DATA is the path data matrix of radar R1 and R2, expressed as: DATA = [o1 o2 ... o c ] T , where o c It is the detection data of its path, represented by o c =[j,D,A,F], c is the detection data number of its path, which is less than or equal to the number of detection data of its path; Extract data from the distance matrix A and store it in the path storage matrix Y; The path storage matrix Y is traversed to output a result data set.

7. The two-dimensional space target pairing method according to claim 6, characterized in that: The traversing the path storage matrix Y to output the result data set comprises the following steps: Step S1: Initialize parameters, define k=1, a=1, b=1, c=1, and execute step S2; Step S2: Extract radar pair array y from Y k , execute step S3; Step S3: Extract the radar pair array y k m a 、n b , execute step S4; Step S4: According to R1 and R2, k Extract it path o c , execute step S5; Step S5: Determine m a 、n b , o c Whether it meets the distance threshold, if it does, m a 、n b , o c After adding the result data set, execute step S6; Step S6: define c=c+1, determine o c Does it exist? If so, go to step S4; otherwise, go to step S7; Step S7: define b=b+1, c=1, and determine n b Does it exist? If so, go to step S3; otherwise, go to step S9; Step S9: define a=a+1, b=1, c=1, and determine m a Does it exist? If so, go to step S3; otherwise, go to step S10; Step S10: define k=k+1, a=1, b=1, c=1, and determine y k Does it exist? If so, execute step S2; otherwise, output the result data set.

8. The two-dimensional space target pairing method according to claim 6, characterized in that: When extracting data from the distance matrix A and storing it in the path storage matrix Y, the self-path data and other-path data of R1 and R2 are judged, and if the pairing condition is met, they are stored; The judgment condition is expressed as: the distance of the round trip path is consistent with the Doppler information, expressed as: Among them, ε1 is the distance threshold, and ε2 is the Doppler threshold.

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