Method for detecting track of large ship target by radar against sea and storage medium

Abstract

The embodiment of the present application provides a kind of radar sea detection large ship target track detection method and storage medium, belong to radar sea detection technical field.The detection method includes: obtaining radar measurement value;Judge whether the radar measurement value is target point;In the case where the radar measurement is target point, the target point is positioned.The radar sea detection large ship target track detection method provided by the present application judges whether the radar measurement value is target point first, then determines whether the target point is strong point target, if the target point is strong point target, then main lobe constraint filtering and two-dimensional condensation are needed, to obtain effective target point, so that radar detection result is further concentrated, effectively improve the detection positioning precision of large ship target.

Description

Technical Field

[0001] This invention relates to the field of radar maritime detection technology, and specifically to a method and storage medium for detecting the trajectory of large ship targets using radar. Background Technology

[0002] Radar detection of the sea surface can perform wide-area searches and detection of moving ship targets, obtaining information such as the position, speed, and direction of travel of the targets, thus enabling the detection, tracking, and localization of sea surface targets. However, the sea surface working environment is complex, the statistical characteristics of sea clutter are unstable, and the target characteristics are usually unknown, which brings great difficulties to achieving constant false alarm rate (CFAR) detection and high-precision localization of sea surface targets.

[0003] Surface targets vary in size, with large targets exhibiting a large backscattering cross-section, resulting in higher signal-to-clutter (SCC) ratios during signal processing. These targets are also more visible in multi-wavelength observations, which is beneficial for detection. However, the high SCC ratio of large targets also means they are more likely to enter the system from the edges of the main lobe or side lobes of the beam. The angular measurement error of the original point detected at these edges or side lobes increases, deviating from the true angular measurement value. This causes the observed original point positions of the same target to disperse in the azimuth direction, exceeding the reasonable convergence range. In this case, the original points with larger angular measurement errors participate in track formation, significantly reducing track positioning accuracy and leading to inaccurate heading and speed estimations. In particular, dispersed original points can cause track splitting of large ships, creating false tracks, reducing target positioning accuracy, and affecting the final surface reconnaissance results.

[0004] In the process of realizing this invention, the inventors of this application discovered that the above-mentioned solutions in the prior art have the defect of reducing the accuracy of target positioning. Summary of the Invention

[0005] The purpose of this invention is to provide a method and storage medium for detecting the track of a large ship target using radar at sea. This method and storage medium improve the positioning accuracy of the large ship target.

[0006] To achieve the above objectives, embodiments of the present invention provide a method for detecting the trajectory of a large ship target using radar at sea, comprising:

[0007] Acquire radar measurements;

[0008] Determine whether the radar measurement value is the target point;

[0009] If the radar measurement indicates that the target point is a target point, the target point is located.

[0010] Determine whether the target point is a strong target;

[0011] If the target point is determined to be a strong target, main lobe beam constraint filtering is applied to the target point, and qualified target points are output.

[0012] The qualified target points are aggregated in two dimensions to obtain a rectangular region and multiple target points within the rectangular region;

[0013] Valid target points are generated based on the qualified target points and multiple target points in the rectangular region.

[0014] Optionally, determining whether the radar measurement value is a target point includes:

[0015] The signal-to-clutter ratio of the radar measurement is calculated according to formula (1).

[0016] SCNR=10lg(S)-10lg(C+N), (1)

[0017] Wherein, SCNR is the signal-to-clutter-to-noise ratio of the radar measurement, S is the signal energy of the radar measurement, C is the background clutter of the radar measurement, and N is the noise energy of the radar measurement;

[0018] Determine whether the signal-to-clutter-to-noise ratio of the radar measurement is greater than or equal to the detection threshold.

[0019] If the signal-to-clutter-to-noise ratio of the radar measurement is greater than or equal to the detection threshold, the radar measurement is determined to be a target point, and the target point is located.

[0020] If the signal-to-clutter ratio of the radar measurement is less than the detection threshold, the radar measurement is determined to be interference, and the target point is discarded.

[0021] Optionally, if the radar measurement is determined to be a target point, locating the target point includes:

[0022] The amplitude ratio of the sum and difference beams at the target point is calculated according to formula (2).

[0023]

[0024] Where μ is the amplitude ratio of the sum and difference beams at the target point, Σ is the complex form of the sum beam at the target point, and Σ = Σ I +jΣ Q , Σ I Let Σ be the real part of the sum of the target point and the beam. Q Let Δ be the imaginary part of the sum beam of the target point, and Δ be the complex form of the difference beam of the target point, where Δ = Δ I +jΔ Q Δ ILet Δ be the real part of the difference beam at the target point. Q Let || be the imaginary part of the difference beam at the target point, and || be the modulus value.

[0025] The angle value of the target point is obtained based on the amplitude ratio of the sum beam and the difference beam at the target point.

[0026] Optionally, if the radar measurement is determined to be a target point, locating the target point further includes:

[0027] The phase ratio of the sum and difference beams at the target point is calculated according to formula (3).

[0028]

[0029] in, The sum and difference beams of the target point are phase ratios, and atan is the arctangent function;

[0030] Determine whether the phase ratio of the sum and difference beams of the target point is greater than or equal to 0;

[0031] If the phase ratio of the sum and difference beams at the target point is greater than or equal to 0, the sign of the angle value is determined to be positive.

[0032] If the phase ratio of the sum and difference beams of the target point is less than 0, the sign of the angle value is determined to be negative.

[0033] Optionally, determining whether the target point is a strong target includes:

[0034] The threshold value for strong point targets is calculated according to formula (4).

[0035] Th1 = Th + α const (4)

[0036] Where Th1 is the threshold value of the strong point target, Th is the detection threshold value, and α const It is a constant;

[0037] Determine whether the signal-to-noise ratio (SNR) of the target point is greater than the threshold value of the strong target.

[0038] If the signal-to-noise ratio of the target point is greater than the threshold value of the strong target, the target point is determined to be a strong target.

[0039] If the signal-to-noise ratio of the target point is less than or equal to the threshold value of the strong target, the target point is output as a general target.

[0040] Optionally, if the target point is determined to be a strong target, main lobe beam constraint filtering is performed on the target point, and qualified target points are output, including:

[0041] The threshold for the main lobe beam constraint filtering angle range is calculated according to formula (5).

[0042]

[0043] Where, θ th The threshold for the main lobe beam constraint filtering angle range, where β is a constant and θ is... 3dB θ is the main lobe width of the radar operating beam. error To ensure positioning accuracy, determine whether the angle value is greater than or equal to the threshold.

[0044] Determine whether the angle value is greater than or equal to the threshold.

[0045] If the angle value is greater than or equal to the threshold, the target point is determined to be within the main lobe beam range, and the target point is output as a qualified target point.

[0046] If the angle value is less than the threshold, the target point is determined to be outside the main lobe beam range and is discarded.

[0047] Optionally, two-dimensional aggregation is performed on the qualified target points to obtain a rectangular region and multiple target points within the rectangular region, including:

[0048] The range of the condensation unit is calculated according to formula (6).

[0049]

[0050] Among them, R bin L represents the range of the distance-oriented condensation unit. ship For the captain, C is the speed of light, and F is the speed of light. s The sampling rate.

[0051] Optionally, performing two-dimensional aggregation on the qualified target points to obtain a rectangular region and multiple target points within the rectangular region further includes:

[0052] The azimuth condensation unit range is calculated according to formula (7).

[0053] A bin =L ship / (rρ azi (7)

[0054] Among them, A bin The azimuth condensation unit range is defined as r, the effective distance is ρ. aziThis refers to the azimuth resolution.

[0055] A rectangular region is generated based on the distance-oriented condensation unit range and the azimuth-oriented condensation unit range.

[0056] Optionally, generating valid target points based on the qualified target points and multiple target points within the rectangular region includes:

[0057] Determine whether the signal-to-noise ratio of the qualified target point is greater than that of any target point in the rectangular region;

[0058] If the signal-to-noise ratio of the qualified target point is greater than that of any target point in the rectangular region, the qualified target point is output as a valid target point.

[0059] If the signal-to-noise ratio of the qualified target point is not greater than that of any target point in the rectangular region, the qualified target point is discarded.

[0060] On the other hand, the present invention also provides a computer-readable storage medium storing instructions for being read by a machine to cause the machine to perform any of the above-described detection methods.

[0061] Through the above technical solution, the radar detection method for detecting the track of large ships at sea provided by the present invention first determines whether the radar measurement value is a target point, then determines whether the target point is a strong target. If the target point is a strong target, main lobe constraint filtering and two-dimensional aggregation are required to obtain effective target points, so that the radar detection results are further concentrated, effectively improving the detection and positioning accuracy of large ships.

[0062] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0063] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0064] Figure 1 This is a flowchart of a radar method for detecting the trajectory of a large ship target at sea according to an embodiment of the present invention;

[0065] Figure 2 This is a flowchart of the target point determination method in a radar-based method for detecting the trajectory of a large ship target at sea, according to an embodiment of the present invention.

[0066] Figure 3This is a flowchart of the target point localization process in a radar-based method for detecting the trajectory of a large ship target at sea, according to an embodiment of the present invention.

[0067] Figure 4 This is a flowchart of the strong point target judgment process in a radar detection method for detecting the track of a large ship target at sea according to an embodiment of the present invention.

[0068] Figure 5 This is a flowchart of a radar method for detecting the trajectory of a large ship target in maritime surveillance, according to an embodiment of the present invention, in the process of filtering strong point targets.

[0069] Figure 6 This is a flowchart of the effective target point output in a radar method for detecting the trajectory of a large ship target in the sea, according to an embodiment of the present invention.

[0070] Figure 7 This is a method for detecting the trajectory of a large ship target using radar according to an embodiment of the present invention, which includes a sum-difference beam pattern and an angle measurement curve.

[0071] Figure 8 This is an example diagram of the detection and positioning of target points before and after main lobe constraint filtering in a radar method for detecting the trajectory of a large ship target in maritime surveillance according to an embodiment of the present invention.

[0072] Figure 9 This is an example diagram of the trajectory before and after main lobe constraint filtering in a radar method for detecting the trajectory of a large ship target at sea according to an embodiment of the present invention. Detailed Implementation

[0073] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0074] Figure 1 This is a flowchart of a radar method for detecting the trajectory of a large ship target at sea, according to one embodiment of the present invention. Figure 1 In this context, the detection method includes:

[0075] In step S10, radar measurement values ​​are acquired. These radar measurement values ​​are the measurements of the position and other information of large targets such as ships on the sea surface after sea surface detection.

[0076] In step S11, it is determined whether the radar measurement value is a target point. First, a preliminary judgment is made using CFAR detection technology to determine whether the radar measurement value is a target point, thus achieving initial screening. Specifically, CFAR detection technology maximizes the detection probability while maintaining a constant false alarm rate. This constraint is used to set the CFAR detection threshold, i.e., the threshold for determining the target point.

[0077] In step S12, if the radar measurement value is determined to be a target point, the target point is located. If the radar measurement value is indeed a target point, further location of the target point is required.

[0078] In step S13, it is determined whether the target point is a strong target. Specifically, after the target point is identified using CFAR detection technology, it is further divided into strong and weak targets. Weak targets are defined as target points of small targets, and the target point of the small target is output.

[0079] In step S14, if the target point is determined to be a strong target, main lobe beam constraint filtering is performed on the target point, and qualified target points are output. Specifically, if the target point is a strong target, main lobe beam constraint filtering needs to be performed on the strong target to obtain high-quality target points entering from the main lobe of the beam, i.e., qualified target points.

[0080] In step S15, the qualified target points are subjected to two-dimensional aggregation to obtain a rectangular region and multiple target points within the rectangular region. Specifically, the qualified target points output by the main lobe beam constraint are subjected to two-dimensional aggregation at multiple distances and from multiple azimuth angles, thereby obtaining a rectangular region and multiple target points within the rectangular region.

[0081] In step S16, valid target points are generated based on qualified target points and multiple target points within a rectangular region. Specifically, the qualified target points and multiple target points within the rectangular region are compared to identify the point with the strongest energy within the rectangular region, which is then output as the valid target point, serving as the radar's detection result for large targets.

[0082] In steps S10 to S16, the radar measurement value is initially assessed to determine if it represents a target point. If the radar measurement value is a target point, further assessment is conducted to determine if it is a strong target. If the target point is a strong target, main lobe constraint filtering is applied, and qualified target points are output. Finally, two-dimensional aggregation is performed on the qualified target points, and the effective target points within the rectangular region formed by the two-dimensional aggregation are obtained. This represents the detection results for large targets such as large ships. These detection results are used for track positioning, making the track more focused and accurate.

[0083] In traditional radar detection of the sea, large ships and other targets have high signal-to-clutter ratios, making them prone to entering the system from the edges or sidelobes of the main lobe. The angular measurement error increases when these targets are detected at the main lobe edges or sidelobes, deviating from the true angular measurement value. This causes the observed original point positions of the same target to disperse in the azimuth direction, exceeding the reasonable convergence range, resulting in poor track positioning accuracy and inaccurate heading and speed estimation. In this embodiment of the invention, a main lobe-constrained filtering method is used for strong point targets. This ensures that the qualified target points output by large target detection are high-quality radar measurements from the main lobe beam, thus filtering the radar detection results. Simultaneously, two-dimensional convergence further filters the radar detection results, making the acquisition of large ship target tracks more accurate, improving the detection and positioning accuracy of large ship targets, and reducing the false alarm rate.

[0084] In this embodiment of the invention, when using CFAR detection technology to detect whether a radar measurement value is a target point, it is necessary to calculate the signal-to-clutter-to-noise ratio (SCNR) of the radar measurement value and determine the SCNR of the radar measurement value. The specific determination steps can be as follows: Figure 2 As shown. Specifically, in Figure 2 In addition, the detection method may also include:

[0085] In step S20, the signal-to-clutter ratio of the radar measurement is calculated according to formula (1).

[0086] SCNR=10lg(S)-10lg(C+N), (1)

[0087] Wherein, SCNR is the signal-to-clutter ratio of the radar measurement, in decibels (dB), S is the signal energy of the radar measurement, C is the background clutter of the radar measurement, and N is the noise energy of the radar measurement.

[0088] In step S21, it is determined whether the signal-to-clutter ratio of the radar measurement is greater than or equal to the detection threshold Th.

[0089] In step S22, if the signal-to-clutter ratio (SNR) of the radar measurement value is greater than or equal to the detection threshold Th, the radar measurement value is determined to be a target point, and the target point is located. Specifically, if the SNR of the radar measurement value is greater than or equal to the detection threshold Th, it indicates that the radar measurement value is a target point, and the target point needs to be located.

[0090] In step S23, if the signal-to-clutter ratio (SNR) of the radar measurement is less than the detection threshold Th, the radar measurement is determined to be interference, and the target point is discarded. Specifically, if the SNR of the radar measurement is less than the detection threshold Th, it indicates that the radar measurement is interference, and the radar measurement is discarded.

[0091] In steps S20 to S23, the signal-to-clutter ratio (SCR) of the acquired radar measurement value is first calculated, and then the SCR is compared with the detection threshold Th. If the SCR of the radar measurement value is greater than or equal to the detection threshold Th, it indicates that the radar measurement value is a target; otherwise, it is interference. This enables the preliminary judgment and screening of the radar measurement value to obtain target points that initially meet the requirements of the radar detection results.

[0092] In this embodiment of the invention, after acquiring the target point, it is also necessary to locate the target point. Specifically, according to the principle of single-pulse angle measurement, there is a one-to-one correspondence between the ratio of the sum and difference beams and the beam angle. Therefore, the target point can be located by measuring its angle and direction based on this relationship. Specifically, the steps for acquiring the angle value of the target point are as follows: Figure 3 As shown. Specifically, in Figure 3 In this context, the detection method may include:

[0093] In step S30, the amplitude ratio of the sum and difference beams at the target point is calculated according to formula (2).

[0094]

[0095] Where μ is the amplitude ratio of the sum and difference beams at the target point, Σ is the complex form of the sum beam signal at the target point, and Σ = Σ I +jΣ Q , Σ I Let Σ be the real part of the sum of the target point and the beam signal. Q Let be the imaginary part of the sum beam signal at the target point, and Δ be the complex form of the difference beam signal at the target point, where Δ = Δ I +jΔ Q Δ I Let Δ be the real part of the difference beam signal at the target point. Q Let || be the imaginary part of the difference beam signal at the target point, and || be the modulus value.

[0096] In step S31, the angle value of the target point is obtained based on the amplitude ratio of the sum and difference beams. In practical applications, given the antenna's sum and difference beam patterns, an angle measurement curve corresponding to the amplitude ratio of the sum and difference beams and the beam angle can be established. Therefore, the corresponding angle value (i.e., the angle value of the target point) can be obtained based on the amplitude ratio of the sum and difference beams. Figure 7 As shown in the example. Specifically, to improve processing speed, the angle measurement curve can also be quantified to obtain an angle measurement table, and angle measurement can be performed by looking up the table, which is more convenient and faster.

[0097] In step S32, the phase ratio of the sum and difference beams at the target point is calculated according to formula (3).

[0098]

[0099] in, Let be the phase ratio of the sum and difference beams at the target point, and atan be the arctangent function.

[0100] In step S33, it is determined whether the phase ratio of the sum beam and the difference beam of the target point is greater than or equal to 0.

[0101] In step S34, if the phase ratio of the sum and difference beams of the target point is greater than or equal to 0, the sign of the angle value is determined to be positive. Specifically, if the phase ratio of the sum and difference beams of the target point is greater than or equal to 0, it indicates that the sign of the angle value of the target point is positive.

[0102] In step S35, if the phase ratio of the sum and difference beams of the target point is less than 0, the sign of the angle value is determined to be negative. Specifically, if the phase ratio of the sum and difference beams of the target point is less than 0, it indicates that the sign of the angle value of the target point is negative.

[0103] In steps S30 to S35, the angle value of the target point is calculated based on the amplitude ratio of the sum and difference beams of the target point. Then, the direction of the target point, i.e., whether it comes from the left or right half beam direction, is determined based on the magnitude of the phase ratio of the sum and difference beams of the target point, thereby achieving reliable positioning of the target point.

[0104] In this embodiment of the invention, in order to determine whether the target point is a general target or a strong target, it is necessary to further screen the target point. The specific screening steps can be as follows: Figure 4 As shown. Specifically, in Figure 4 In addition, the detection method may also include:

[0105] In step S40, the threshold value of the strong point target is calculated according to formula (4).

[0106] Th1 = Th + α const (4)

[0107] Where Th1 is the threshold value for strong point targets, Th is the detection threshold value, and α const It is a constant, and α const ≥0, α const It was calculated based on the difference in scattering area between large and small boats in the classic model.

[0108] In step S41, it is determined whether the signal-to-noise ratio of the target point is greater than the threshold value of the strong target.

[0109] In step S42, if the signal-to-noise ratio (SNR) of the target point is greater than the threshold value for strong targets, the target point is determined to be a strong target. Specifically, if the SNR of the target point is greater than that of a strong target, the located target point can be marked as a strong target and then subjected to filtering processing.

[0110] In step S43, if the signal-to-clutter ratio (SNR) of the target point is less than or equal to the threshold value for strong targets, the target point is output as a general target. Specifically, if the SNR of the target point is less than or equal to the threshold value for strong targets, it indicates that the target point is a weak target (small target), and it can be directly output as a general target. This ensures that weak targets are not lost, while also suppressing track splitting of large targets such as large ships.

[0111] In steps S40 to S43, the threshold value of strong targets is obtained, and the already located target point is compared with the threshold value of the strong target. If the target point is greater than the threshold value of the strong target, it is determined to be a strong target, and further filtering processing is performed. Conversely, if the target point is less than or equal to the threshold value of the strong target, it is considered a weak target and is directly output. This method ensures that weak targets are not lost while suppressing track splitting of large targets, making it more widely applicable.

[0112] In this embodiment of the invention, to improve the accuracy of radar detection results, it is also necessary to filter strong point targets to discard target points where large targets enter the radar system from the edge of the main lobe or the side lobe of the beam. Specifically, the filtering steps can be as follows: Figure 5 As shown. Specifically, in Figure 5 In addition, the detection method may also include:

[0113] In step S50, the threshold for the main lobe beam constraint filtering angle range is calculated according to formula (5).

[0114]

[0115] Where, θ th The threshold for the main lobe beam constraint filtering angle range, where β is a constant and θ is... 3dB θ is the main lobe width of the radar operating beam. error For positioning accuracy, determine whether the angle value is greater than or equal to a threshold. Specifically, θ error These are known parameters, typically system performance requirements.

[0116] In step S51, it is determined whether the angle value is greater than or equal to the threshold.

[0117] In step S52, if the angle value is greater than or equal to a threshold, the target point is determined to be within the main lobe beam range, and the target point is output as a qualified target point. High-energy, large targets tend to enter the radar system from the edge of the main lobe or the sidelobe. For these target points entering from the main lobe or sidelobe, the angle measurement error increases, deviating from the true angle measurement value, causing the observed target point positions to be dispersed in the azimuth direction. In this case, the dispersed target points participate in track formation, leading to track splitting for large ships and the formation of multiple false tracks, reducing the accuracy of target positioning. Therefore, retaining high-quality target points entering from the main lobe can effectively suppress track separation for large targets.

[0118] In step S53, if the angle value is less than a threshold, the target point is determined to be outside the main lobe beam range and is discarded. Similarly, discarding target points entering from the edge of the main lobe or side lobe can improve the accuracy of large target tracks.

[0119] In steps S50 to S53, after calculating the threshold for the main lobe beam constraint filtering angle range, the angle value of the strong target is compared with the threshold. If the angle value of the strong target is greater than or equal to the threshold, it indicates that the strong target is within the main lobe beam range, and the strong target is retained; otherwise, the strong target is discarded. By limiting the strong target by the threshold for the main lobe beam constraint filtering angle range, the influence of target points entering from the main lobe edge or side lobe on the splitting of large target tracks can be reduced, thus effectively improving the accuracy of large target tracks. Specifically, the results of continuous multi-frame detection and positioning of target points of large ship targets before and after main lobe constraint can be as follows: Figure 8 As shown in the example, the trajectory results of the large ship target before and after the main lobe constraint can be as follows: Figure 9 The example shown.

[0120] In this embodiment of the invention, after constraining the main lobe beam of the strong target, it is also necessary to obtain effective target points based on the strong target that meets the constraint conditions. Specific steps may include, for example: Figure 6 So, specifically, in Figure 6 In this context, the detection method may include:

[0121] In step S60, the range of the distance-oriented condensation unit is calculated according to formula (6).

[0122]

[0123] Among them, R bin For the distance to the condensation unit range, L ship For the captain, C is the speed of light, and F is the speed of light. s The sampling rate.

[0124] In step S61, the azimuth condensation unit range is calculated according to formula (7).

[0125] A bin =L ship / (rρ azi (7)

[0126] Among them, A bin The azimuth condensation unit range is r, the effective distance is ρ. azi This represents the azimuth resolution.

[0127] In step S62, a rectangular region is generated based on the range of the distance-oriented condensation unit and the range of the azimuth-oriented condensation unit.

[0128] In step S63, it is determined whether the signal-to-noise ratio of the qualified target point is greater than that of any target point in the rectangular region.

[0129] In step S64, if the signal-to-clutter ratio (SNR) of a qualified target point is greater than that of any target point in the rectangular area, the qualified target point is output as a valid target point. Specifically, if the SNR of a qualified target point is greater than that of any target point in the rectangular area, it indicates that the qualified target point has the highest energy, and this qualified target point is output as a valid target point, thus serving as the radar's detection result for a large target.

[0130] In step S65, if the signal-to-clutter ratio (SNR) of a qualified target point is not greater than that of any target point within the rectangular region, the qualified target point is discarded. Specifically, if the SNR of a qualified target point is not greater than that of any target point within the rectangular region, it means that the qualified target point is not the one with the highest energy within the rectangular region, and therefore it is discarded. In essence, by using the target point with the highest output energy (highest SNR) as the criterion, the target point with the highest energy within the rectangular region is output as the radar's detection result for large targets. This makes the radar's detection results for large targets more concentrated, reducing the risk of track splitting for large targets.

[0131] In steps S60 to S65, the range of the two-dimensional convergent unit and the azimuth of the convergent unit are first obtained. Then, a rectangular range of the two-dimensional convergent unit is obtained based on these range-coordinated ranges and azimuth-coordinated unit azimuths. The target point with the greatest capability within this rectangular range is taken as the radar detection result. This method makes the detection results of large targets more concentrated, reducing the risk of track fragmentation for large targets.

[0132] On the other hand, the present invention also provides a computer-readable storage medium storing instructions for being read by a machine to cause the machine to perform any of the above-described detection methods.

[0133] Through the above technical solution, the radar detection method for detecting the track of large ships at sea provided by the present invention first determines whether the radar measurement value is a target point, then determines whether the target point is a strong target. If the target point is a strong target, main lobe constraint filtering and two-dimensional aggregation are required to obtain effective target points, so that the radar detection results are further concentrated, effectively improving the detection and positioning accuracy of large ships.

[0134] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0135] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0136] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0137] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0138] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0139] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0140] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0141] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0142] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for detecting the trajectory of a large ship target using radar at sea, characterized in that, include: Acquire radar measurements; Determining whether the radar measurement value is a target point includes: Determine whether the signal-to-clutter-to-noise ratio of the radar measurement is greater than or equal to the detection threshold. If the signal-to-clutter-to-noise ratio of the radar measurement is greater than or equal to the detection threshold, the radar measurement is determined to be a target point, and the target point is located. If the signal-to-clutter-to-noise ratio of the radar measurement is less than the detection threshold, the radar measurement is determined to be interference, and the target point is discarded. If the radar measurement is determined to be a target point, the target point is located, including: The angle value of the target point is obtained based on the amplitude ratio of the sum beam and the difference beam at the target point; Determine whether the phase ratio of the sum and difference beams of the target point is greater than or equal to 0; If the phase ratio of the sum and difference beams at the target point is greater than or equal to 0, the sign of the angle value is determined to be positive. If the phase ratio of the sum and difference beams of the target point is less than 0, the sign of the angle value is determined to be negative. Determining whether the target point is a strong target includes: The threshold value for strong point targets is calculated according to formula (1). ，（1） in, This is the threshold value for the strong point target. The detection threshold value is... It is a constant; Determine whether the signal-to-noise ratio (SNR) of the target point is greater than the threshold value of the strong target. If the signal-to-noise ratio of the target point is greater than the threshold value of the strong target, the target point is determined to be a strong target. If the target point is determined to be a strong target, main lobe beam constraint filtering is applied to the target point, and qualified target points are output, including: The threshold for the main lobe beam constraint filtering angle range is calculated according to formula (2). ，（2） in, The threshold for the main lobe beam constraint filtering angle range. It is a constant. The main lobe width of the radar operating beam. For positioning accuracy; Determine whether the angle value is greater than or equal to the threshold. If the angle value is greater than or equal to the threshold, the target point is determined to be within the main lobe beam range, and the target point is output as a qualified target point. If the angle value is less than the threshold, the target point is determined to be outside the main lobe beam range and is discarded. Two-dimensional aggregation is performed on the qualified target points to obtain a rectangular region and multiple target points within the rectangular region, including: The range of the condensation unit is calculated according to formula (3). ，（3） in, The distance to the condensation unit range, As captain, At the speed of light, Sampling rate; The azimuth condensation unit range is calculated according to formula (4). ，（4） in, The azimuth condensation unit range is defined as such. The effective range, This refers to the azimuth resolution. A rectangular region is generated based on the distance-oriented cohesion unit range and the azimuth-oriented cohesion unit range; Valid target points are generated based on the qualified target points and multiple target points in the rectangular region.

2. The detection method according to claim 1, characterized in that, Determining whether the radar measurement value is a target point includes: The signal-to-clutter ratio of the radar measurement is calculated according to formula (5). ，（5） in, The signal-to-clutter ratio of the radar measurement. The signal energy of the radar measurement value. The background clutter of the radar measurements. The noise energy of the radar measurement is denoted as .

3. The detection method according to claim 2, characterized in that, If the radar measurement is determined to be a target point, locating the target point includes: The amplitude ratio of the sum and difference beams at the target point is calculated according to formula (6). ，（6） in, The sum and difference beam amplitude ratios of the target point. Let the sum of the target point and the beam be in complex form. , Let be the real part of the sum of the target point and the beam. Let be the imaginary part of the sum of the target point and the beam. Let be the complex form of the difference beam at the target point. , Let be the real part of the difference beam at the target point. Let be the imaginary part of the difference beam at the target point. This is the modulo value.

4. The detection method according to claim 3, characterized in that, If the radar measurement is determined to be a target point, locating the target point further includes: Calculate the phase ratio of the sum and difference beams at the target point according to formula (7). ，（7） in, The phase ratio of the sum and difference beams at the target point. It is the arctangent function.

5. The detection method according to claim 4, characterized in that, Determining whether the target point is a strong target includes: If the signal-to-noise ratio of the target point is less than or equal to the threshold value of the strong target, the target point is output as a general target.

6. The detection method according to claim 1, characterized in that, Generating valid target points based on the qualified target points and multiple target points within the rectangular region includes: Determine whether the signal-to-noise ratio of the qualified target point is greater than that of any target point in the rectangular region; If the signal-to-noise ratio of the qualified target point is greater than that of any target point in the rectangular region, the qualified target point is output as a valid target point. If the signal-to-noise ratio of the qualified target point is not greater than that of any target point in the rectangular region, the qualified target point is discarded.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that are read by a machine to cause the machine to perform the detection method as described in any one of claims 1 to 6.

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