A method for reducing false tracks of sea detection radar

Abstract

The present invention relates to a method for reducing false tracks of sea detection radar. Before forming tracks, the tracks are subjected to condensation preprocessing, and the weight of the condensed track is calculated. If the weight is greater than a certain threshold, the condensed track is determined to be a real target track and subsequent track processing is performed. Otherwise, the condensed track is determined to be sea clutter and deleted. Subsequent track processing reduces sea clutter tracks, thereby reducing false tracks.

Description

Technical Field

[0001] The invention belongs to the field of radar technology and relates to a method for reducing false tracks of sea detection radars. Specifically, the invention provides a method for reducing false tracks of sea detection radars in a nearshore sea warning zone. Background Art

[0002] When sea detection radar detects ship targets at sea, the sea clutter in the nearshore waters often forms the same track as the ship target.

[0003] A certain type of sea-surveillance radar was tasked with patrolling a coastal area. It was required to monitor targets entering the designated waters and trigger an alarm when a target approached the coastline. Due to frequent winds and high seas in the area, close-range sea clutter often created numerous false target tracks, creating difficulties for the customer.

[0004] Usually, this type of problem is handled by the radar signal processor using sea clutter suppression technology to suppress sea clutter, so that the sea clutter does not form point traces as much as possible, and thus does not form a track. However, in complex sea conditions, especially near-shore waters, sea clutter suppression is difficult to handle. Summary of the Invention

[0005] Technical problems to be solved

[0006] In order to avoid the shortcomings of the existing technology, the present invention proposes a method for reducing false tracks of sea detection radar, and provides a method for reducing false tracks when the sea detection radar performs a warning mission in near-shore waters.

[0007] Technical Solution

[0008] A method for reducing false tracks of sea detection radar, characterized by the following steps:

[0009] Step 1: When the radar signal processor receives the Nth frame of echo data and detects the original traces, it condenses the original traces within the frame and calculates the number of range gates Nr and the amplitude Amp spanned by the condensed traces;

[0010] Step 2: When the reliable condensed point traces of the N+1th frame are received, the reliable condensed points in the Nth frame and the N+1th frame are merged to generate new condensed point traces;

[0011] Merging principle: All points that are 3*a apart and 1*b apart are merged into the Nth frame number of condensed traces. The number of condensed traces Nr is equal to the number of traces with the largest Amp in the merged condensed traces. Where: a is the radar range accuracy, and b is the radar azimuth beamwidth.

[0012] Step 3: When the condensed traces at the N+2th frame are received, the condensed traces at the N+2th frame and the condensed traces at the Nth frame are merged according to the merging principle to generate new condensed traces at the Nth frame.

[0013] Step 4: When the condensed traces at the N+3, N+4, and N+m frames are received, repeat steps 2 and 3. When the orientation of the N+m frame differs from the orientation of the N frame by an angle b, calculate the weight of the condensed trace at the N frame, A = Nr * Nh.

[0014] Step 5: When A 阀值 When , the condensed points are judged to be false clutter points and the point traces are deleted. Otherwise, the point traces are judged to be real targets and the condensed points are used as valid data for track processing.

[0015] The condensed traces at the N+2th frame that cannot be merged in step 3 are further merged with the condensed traces at the Nth and N+1th frames that have not been merged. If the conditions are met, new condensed traces are generated.

[0016] The A 阀值 Related to radar parameters and determined by the radar used.

[0017] Beneficial effects

[0018] The present invention proposes a method for reducing false tracks of sea detection radar. Before forming a track, the track is subjected to agglomeration preprocessing, and the weight of the agglomerated track is calculated. If the weight is greater than a certain threshold, the agglomerated track is determined to be a real target track and subsequent track processing is performed. Otherwise, the agglomerated track is determined to be sea clutter and deleted. Subsequent track processing reduces sea clutter tracks, thereby reducing false tracks.

[0019] Using the same set of radar sampling data for testing, the number of false tracks displayed by the radar terminal was significantly reduced, meeting the system usage requirements. Figure 2 Figure a on the left shows the terminal interface displayed during normal radar operation. The target track in the upper left corner is a moving ship, and the three targets tracked in the lower right corner are false targets formed by waves. After processing this data using the present invention, the effect is shown in Figure b on the right. The false target formed by the waves in the lower right corner has disappeared, and the ship in the upper left corner can still form a normal track. By comparing the two images, the false tracks formed by the waves can be effectively suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 : Schematic diagram of the method of the present invention

[0021] Figure 2 :Effect diagram of the embodiment of the method of the present invention DETAILED DESCRIPTION

[0022] ​The present invention will now be further described with reference to the embodiments and accompanying drawings:

[0023] The core idea of the present invention is to perform agglomeration preprocessing on the points before forming a track, calculate the weight of the agglomerated points, and determine that the agglomerated points are true target points if the weight is greater than a certain threshold, and perform subsequent track processing. Otherwise, the agglomerated points are determined to be sea clutter and deleted. Subsequent track processing reduces sea clutter points, and thus reduces false tracks.

[0024] The method of the present invention comprises the following steps:

[0025] [1] When the radar is turned on, the signal processor receives the Nth frame of echo data, detects the original traces, performs intra-frame condensation on the original traces, calculates the number of range gates Nr and amplitude Amp spanned by the condensed traces, and reports the position information of the condensed traces to the data processor. The reported condensed trace information includes the number of range gates spanned by the traces.

[0026] [2] After the data processor receives the N+1th frame signal condensation trace reported by the signal processor, it performs inter-frame merging processing on the signal condensation traces in the Nth frame and the N+1th frame, and merges all points that are 3*a away and 1*b away into the Nth frame signal condensation points (a is the radar distance accuracy, b is the radar azimuth beamwidth). The number of signal condensation points Nr is equal to the Nr of the maximum point trace Amp in the merged signal condensation traces, and the number of merged signal condensation points Nh is recorded at the same time;

[0027] [3] The data processor continues to receive the N+2 frame signal condensation traces reported by the signal processor, and merges the N+2 frame signal condensation traces with the N frame signal condensation traces according to step 2. The N+2 frame signal condensation traces that cannot be merged are continued to be merged with the N and N+1 frame signal condensation traces that have not been merged. If the conditions are met, a new signal condensation trace is generated.

[0028] [4] The data processor continues to receive the condensed traces at the N+3, N+4, and N+m frames reported by the signal processor, and repeats steps 2 and 3 until the azimuth of the N+m frame differs from the azimuth of the N frame by an angle of b. Then, a threshold judgment is performed to calculate the weight of the condensed trace at the Nth frame, A=Nr*Nh. When A 阀值 (Different radar parameters have different thresholds, and the threshold of this radar is 20), the condensation points are determined to be false clutter points, and the data processor deletes the point traces. Otherwise, the point traces are determined to be real targets, and the data processor sends the condensation points to the subsequent process for track processing. Specific embodiment:

[0030] ​1. Radar parameters: radar range accuracy a = 10 meters, radar azimuth beam width b = 1.2°, radar scanning one frame corresponds to an azimuth of 0.3°, A 阈值 =20;

[0031] 2. When the radar is powered on, the radar signal processor receives the first frame of echo data and detects the original traces. It then performs intra-frame condensation on the original traces to form condensed traces 1DJ1 and 1DJ2. The parameters are as follows:

[0032] Faith Focus Distance (meters) Azimuth (°) Crossing the distance gate Amplitude 1DJ1 5410 91.5 5 1100 1DJ2 3720 126.3 1 730

[0033] 3. The radar signal processor receives the second frame of echo data and detects the original traces. It then performs intra-frame condensation on the original traces to form condensed traces 2DJ1, 2DJ2, and 2DJ3. The parameters are as shown in the following table.

[0034] Faith Focus Distance (meters) Azimuth (°) Crossing the distance gate Amplitude 2DJ1 5420 91.8 7 1200 2DJ2 4070 271.1 5 1000 2DJ3 3720 126.6 1 200

[0035] According to the rules, the condensation points 1DJ1 and 2DJ1 at the first and second frames are merged, and 1DJ2 and 2DJ3 are merged to form the condensation points 1DJSC1 and 1DJSC2 at the first frame. The parameters are as follows:

[0036]

[0037] 4. The radar signal processor receives the third frame of echo data and detects the original traces. It then performs intra-frame condensation on the original traces to form the signal condensed trace 3DJ1. The parameters are as shown in the following table.

[0038] Faith Focus Distance (meters) Azimuth (°) Crossing the distance gate Amplitude 3DJ1 5420 92.1 7 1100

[0039] According to the rules, the condensed point 3DJ1 at the third frame and the condensed point trace 1DJSC1 at the first frame are merged to form new condensed points traces 1DJSC1 and 1DJSC2 at the first frame. The parameters are as follows:

[0040]

[0041] 5. The radar signal processor receives the fourth frame of echo data but does not detect the original point trace. At this time, the azimuth of the fourth frame differs from the azimuth of the first array by 0.3*4=1.2°. Calculate the weight of the condensation point at the first frame. The parameters are as follows:

[0042]

[0043] 6. If the weight A=2 of several condensation points 1DJSC2 is less than 20, these condensation points are judged to be false clutter points and are deleted. If the weight A=21 of several condensation points 1DJSC1 is greater than 20, these points are judged to be real targets and are used as valid data for track processing.

Claims

1. A method for reducing false tracks of sea detection radar, characterized in that Here are the steps: Step 1: When the radar signal processor receives the Nth frame of echo data and detects the original traces, it condenses the original traces within the frame and calculates the number of range gates Nr and the amplitude Amp spanned by the condensed traces; Step 2: When the reliable condensed point traces of the N+1th frame are received, the reliable condensed points in the Nth and N+1th frames are merged to generate new condensed point traces. Merging principle: All points that are 3*a apart and 1*b apart are merged into the Nth frame number of condensed traces. The number of condensed traces Nr is equal to the number of traces with the largest Amp in the merged condensed traces. Where: a is the radar range accuracy, and b is the radar azimuth beamwidth. Step 3: When the condensed traces at the N+2th frame are received, the condensed traces at the N+2th frame and the condensed traces at the Nth frame are merged according to the merging principle to generate new condensed traces at the Nth frame. Step 4: When the condensed traces at the N+3, N+4, and N+m frames are received, repeat steps 2 and 3. When the orientation of the N+m frame differs from the orientation of the N frame by an angle b, calculate the weight of the condensed trace at the N frame, A = Nr * Nh. Where: Nh is the number of merged signal condensation points Nh; Step 5: When A 阀值 When , the condensed points are judged to be false clutter points and the point traces are deleted. Otherwise, the point traces are judged to be real targets and the condensed points are used as valid data for track processing.​ 2. The method for reducing false tracks of sea-surveillance radar according to claim 1, characterized in that: The condensed traces at the N+2th frame that cannot be merged in step 3 are further merged with the condensed traces at the Nth and N+1th frames that have not been merged. If the conditions are met, new condensed traces are generated.

3. The method for reducing false tracks of sea-surveillance radar according to claim 1, characterized in that: The A 阀值 Related to radar parameters and determined by the radar used.

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