KR20210111703A - Pulse integration method for providing high resolution radar image and sea surveillance radar system using the same - Google Patents

Abstract

The present invention relates to a pulse integration method capable of providing a high-resolution radar image irrespective of a radar pulse mode in a two-dimensional coastal surveillance radar, and a coastal surveillance radar using the same, comprising: an antenna (100); Consists of a transceiver 200 that transmits a pulse through the antenna 100 or receives a radar raw image signal detected by the antenna 100 by being reflected by an object and a display 300 displaying the received signal on a user screen An A/D conversion module 310 in which the display 300 matches the received radar raw image signal with the azimuth information according to the rotation of the antenna 100 and discretizes it at a detection distance interval set with a constant distance resolution; A signal processing module 320 for extracting the discretized radar raw image data as target detection information after noise reduction and clutter reduction filtering, and a target tracking module for linking the target detection information with a target currently being tracked or adding it as a new target 330 and a display module 340 that displays the radar image output from the signal processing module 320 and target information output from the target tracking module 330 on a user screen, and the signal processing module 320 It has a technical feature of determining whether to perform pulse integration according to whether a radar raw image signal exists in an azimuth range of a predetermined range based on the extracted azimuth corresponding to the row number of the radar extracted image matrix.

Description

PULSE INTEGRATION METHOD FOR PROVIDING HIGH RESOLUTION RADAR IMAGE AND SEA SURVEILLANCE RADAR SYSTEM USING THE SAME

The present invention relates to a pulse integration method and apparatus for providing a high-resolution radar image in a system using a radar, and more particularly, to a pulse integration method capable of providing a high-resolution radar image regardless of a radar pulse mode in a two-dimensional coastal surveillance radar. It relates to a method and a coastal surveillance radar using the same.

Aviation or coast monitoring system collects location information and status information of aircraft/ships using various sensors including radar for route monitoring for safe operation of aircraft or ships, and intrusion monitoring of unidentified aircraft or ships, and from this, Alternatively, it provides various services such as ship tracking monitoring and safe route guidance.

Aerial or coastal surveillance systems using radar track radar images and detected targets to collect accurate location and speed information of aircraft or ships. It transmits signals and receives signals reflected by targets such as ships, terrain such as land and buildings, and oceans such as waves.

In addition, the received radar reflection signal is displayed on the screen of the display after generating a radar image through a signal processing process of several steps in order to attenuate noise and clutter.

Coastal surveillance radar operates in multiple pulse modes, for example, VSP (Very Short Pulse), SP (Short Pulse), MP (Medium Pulse), LP (Long Pulse), VLP (Very Long Pulse), etc. do. Since the pulse repetition frequency (PRF) varies according to the pulse mode, the resolution of the radar raw image data input to the signal processing unit is changed.

In general, in order to provide a constant radar image resolution, the output image resolution of the signal processing unit is set based on the size of the radar raw image data obtainable in the pulse mode having the smallest pulse repetition frequency, or the signal has a variable resolution according to the pulse mode. You can set the resolution of the output image of the processor. Accordingly, there is a problem in that the resolution of the output image of the signal processing unit cannot be avoided in the pulse mode having a low pulse repetition frequency.

KR 10-2007-0025093 A (2007. 3. 8.)

An object of the present invention is to provide a pulse integration method capable of providing an image having a set output image resolution regardless of a pulse mode of a coastal surveillance radar.

Coastal surveillance radar according to the present invention includes an antenna; A coastal surveillance radar comprising a transceiver for transmitting a pulse through the antenna or receiving a radar raw image signal detected by the antenna by being reflected by an object, and a display for displaying the received signal on a user screen, wherein the display is An A/D conversion module that discretizes the radar raw image signal at a detection distance interval set with a constant distance resolution by matching the azimuth information according to the rotation of the antenna. A signal processing module for extracting target detection information, a target tracking module for linking the target detection information with a target being tracked or adding a new target, and a radar image output from the signal processing module and target information output from the target tracking module Consists of a display module that displays on a user screen, wherein the signal processing module determines whether to perform pulse integration according to whether or not there is a radar raw image signal in an azimuth range of a predetermined range centered on the extracted azimuth corresponding to the row number of the radar extracted image matrix. Determining is a technical feature.

)을 설정하고 추출 방위각(

)의 양(+)과 음(-) 방향으로 소정 각도(△θ) 내에 있는 방위각 영역에 있는 레이더 원시 영상 데이터의 방위각(ACP_i)에 대해 원시 영상 데이터를 추출하는 원시 데이터 추출 단계; 상기 원시 데이터 추출 단계에서 추출된 원시 데이터 개수가 0인지 여부를 판단하여, 원시 데이터 개수가 0이라면 추출 방위각(

)에 있는 데이터 소거(S25)하는 펄스 적분 여부 판단 단계 및 상기 원시 데이터 추출 단계(S10)에서 추출된 원시 영상 데이터의 최솟값(ACP_min)과 최댓값(ACP_max)과 추출 방위각(

)의 관계가 아래 [수학식 2]를 만족하면 보간법 처리를 수행하고, 아래 [수학식 4]를 만족하면 외삽법 처리를 수행하는 것을 특징으로 하는 펄스 적분 단계(S30)를 포함하는 것을 기술적 특징으로 한다.The pulse integration method for providing a high-resolution radar image in a coastal surveillance radar according to the present invention is an azimuth (

) and set the extraction azimuth (

) a raw data extraction step of extracting raw image data for _{an azimuth (ACP i} ) of the radar raw image data in an azimuth region within a predetermined angle (Δθ) in positive (+) and negative (-) directions; It is determined whether the number of raw data extracted in the raw data extraction step is 0, and if the number of raw data is 0, the extraction azimuth (

) in the pulse integration to erase (S25) the minimum value (ACP _min ) and the maximum value (ACP _max ) and the extraction azimuth of the raw image data extracted in the raw data extraction step (S10)

) when the relationship of [Equation 2] is satisfied below, interpolation processing is performed, and when the following [Equation 4] is satisfied, extrapolation processing is performed. do it with

[Equation 2]

[Equation 4]

The pulse integration method for providing a high-resolution radar image in a coastal surveillance radar according to the present invention uses the extrapolation method when the resolution of the radar raw image is lower than the output image resolution of the signal processing unit, and performs pulse integration using the interpolation method when the resolution is high. It can provide a constant high-resolution radar image. Accordingly, it is possible to significantly improve the performance of the coast guard system by enabling the detection and tracking of small ships.

1 is an exemplary view of a coastal surveillance radar operating environment to which a pulse integration method for providing a high-resolution radar image in a coastal surveillance radar according to the present invention is applied;
2 is an exemplary diagram of a radar image displayed on a user screen of a radar display;
3 is a configuration diagram of a coastal surveillance radar;
4 is an exemplary diagram of the radar raw image data obtained according to the pulse repetition frequency and the number of revolutions per minute according to the radar pulse mode;
5 is a configuration diagram of a display;
6 is an exemplary view of the structure of radar raw data (A-Scope) obtained from the A/D conversion unit of the display;
7 is an exemplary diagram of a radar raw image (B-Scope) data structure input to a signal processing unit of a display
8 is a block diagram of a signal processing unit;
9 is a flowchart illustrating a process of integrating a pulse using an interpolation method and an extrapolation method in a pulse integrator of a signal processing unit in a pulse integration method for providing a high-resolution radar image in a coastal surveillance radar according to the present invention;

Hereinafter, a pulse integration method for providing a high-resolution radar image in a coastal surveillance radar according to the present invention will be described in detail with reference to the accompanying drawings.

1 is an exemplary view of a coastal monitoring radar operating environment to which a pulse integration method for providing a high-resolution radar image is applied in a coastal monitoring radar according to the present invention. It receives signals reflected by the target (T), such as waves, the sea (S), land, and terrain (L) such as buildings. The received radar signal is displayed on the user screen after generating a radar image through a signal processing process for noise and clutter.

2 is an exemplary diagram of a radar image displayed on a user screen of a radar display. In the radar image 200 , an image T by a target such as a ship, an image S by sea waves, an image L by terrain, and the like may appear. The image (S) caused by the waves may appear temporarily at an unspecified point, which is usually called sea clutter.

3 is a block diagram of a coastal monitoring radar, in which the coastal monitoring radar R transmits a pulse through the antenna 100 and the antenna 100 rotating at a constant cycle or is reflected in an operating environment such as a ship, terrain, and sea to the antenna It is composed of a transceiver 200 for receiving the signal detected in 100 and a display 300 for displaying the received signal on a user screen.

4 is an exemplary view of the radar raw image data obtained according to the pulse repetition frequency and revolutions per minute according to the radar pulse mode. The size of the radar raw image is the pulse received in each azimuth direction while the coast surveillance radar antenna rotates once It can be expressed as discretized data (RangeBin) with respect to the number of and the distance direction for each received pulse. The number of data for the azimuth direction in the radar raw image may be expressed as the product of the pulse repetition frequency 402 and the rotation period of the antenna (60/RPM).

5 is a block diagram of a display, in which the display 300 matches the received analog radar signal with the azimuth information according to the rotation of the antenna and discretizes the A/D conversion module 310 at a detection distance interval set with a constant distance resolution. Signal processing module 320 for extracting target detection information after noise reduction and clutter reduction filtering on the radar raw image data, and a target tracking module 330 for linking target detection information with a target currently being tracked or adding a new target and a display module 340 that displays the radar image output from the signal processing module 320 and target information output from the target tracking module 330 on a user screen.

At this time, the signal processing module 320 receives the radar raw image data from the A/D conversion module 310, compares it with the set output image resolution, and adopts the pulse integration method to which the interpolation method or the extrapolation method is applied according to the result. .

6 is an exemplary diagram of the structure of the radar raw data (A-Scope) obtained from the A/D conversion unit of the display, and the radar raw data (A-Scope) is _{discretized for azimuth data (D A,RAW} ) and distance. It is composed of reflected signal data (D _{T,RAW ) according to the distance.}

7 is an exemplary diagram of the radar raw image (B-Scope) data structure input to the signal processing unit of the display, wherein the radar raw image (B-Scope) is the radar raw data (A-Scope) in which the azimuth data increases or decreases. It is formed in a sequentially stacked form. That is, the radar raw image (B-Scope) is configured in the form of a matrix _{of accumulated azimuth data (D A,RAW} ) and accumulated reflected signal data (D _{T,RAW ).}

8 is an exemplary diagram of a radar extracted image data structure (or data matrix) output from a signal processing unit of a display, by integrating two or more consecutive rows of a radar raw image (B-Scope) into radar extracted image data convert For example, in the case of the SP pulse mode, the radar raw image (B-Scope) has 9600 rows of data {when the radar rotates once, the transmission and reception of the radar signal 9600 times is the radar raw image (B-Scope) of 9600 rows. Scope), and when the radar extracted image is converted to data having 4960 rows (N = 9600, Q = 4960), the radar raw image (B-Scope) belonging to the azimuth range corresponding to 4960 rows ) to create radar-extracted image data with 4960 rows by integrating the data.

9 is a block diagram of a signal processing module. The signal processing module 320 includes a pulse integrator 321 for pulse-integrating a radar raw image by adopting any one of an interpolation method or an extrapolation method, and noise reduction and noise reduction and processing for the pulse-integrated image signal. A noise/clutter processor 323 for cluster attenuation filtering, a target detector 325 that determines whether the signal magnitude of the output image of the noise/clutter processor 323 is equal to or greater than a set threshold, and recognizes a target if it is greater than or equal to the threshold; and It consists of a target information extractor 327 for extracting the azimuth and distance from the image recognized as a target.

10 is a flowchart illustrating a pulse integration process using an interpolation method or an extrapolation method in a pulse integrator of a signal processing module in a pulse integration method for providing a high-resolution radar image in a coastal surveillance radar according to the present invention. In the present invention, pulse integration is performed as follows.

, 이하 ‘추출 방위각’이라 한다)을 설정하고 추출 방위각(

)의 양(+)과 음(-) 방향으로 소정 각도(△θ) 내에 있는 방위각 영역에 있는 레이더 원시 영상 데이터의 방위각(ACP_i)에 대해 원시 영상 데이터를 추출한다(i는 복수 개일 수 있다).① Raw data extraction step (S10): azimuth (

, hereinafter referred to as 'extraction azimuth') and set the extraction azimuth (

) extracts the raw image data for _{the azimuth (ACP i} ) of the radar raw image data in the azimuth region within a predetermined angle (Δθ) in the positive (+) and negative (-) directions (i may be plural) ).

)에 있는 데이터를 소거(S25)한다(데이터를 소거하지 않으면 이전 데이터가 누적되어 자취를 남기게 된다). 만약 원시 데이터가 1개 이상이라면 펄스 적분을 수행하도록 한다.② Pulse integration determination step (S20): Whether the number of raw data extracted in the raw data extraction step (S10) is 0 (for example, when N < Q or Δθ is very small) In other words, it is judged whether or not pulse integration is necessary because there is no raw data, and if the number of raw data is 0, pulse integration is skipped and the extraction azimuth (

) is deleted (S25) (if data is not deleted, previous data is accumulated and a trace is left). If there is more than one raw data, perform pulse integration.

)의 관계에 따라 보간 또는 외삽의 방법으로 펄스 적분을 수행한다.③ Pulse integration step (S30): If it is determined that pulse integration is required in the pulse integration determination step (S20), pulse integration is performed. _{At this time, the minimum value (ACP min} ) and the maximum value (ACP _max ) of the raw image data extracted in the raw data extraction step (S10) and the extraction azimuth (

), pulse integration is performed by means of interpolation or extrapolation.

Specifically, if the following [Equation 2] is satisfied, the interpolation process (S31) is performed, and the elements of the radar extraction image matrix for all combinations of _{ACP i} and ACP _{j (i≠j) satisfying the above [Equation 1]} can be defined by [Equation 3] below {N(i, j) is _{the number of ACP i} , ACP _j combinations, k = 1, 2, 3, ... Q}.

Next, if the following [Equation 4] is satisfied, the extrapolation process (S33) is performed. Similar to the interpolation method, the extrapolation method _{is also calculated for the entire combination of ACP i} and ACP _j (i≠j) satisfying [Equation 1] above, and the elements of the radar extraction image matrix are defined as [Equation 4] below.

By processing the radar image through the above steps, a low-resolution radar screen can be implemented from the high-resolution radar raw image data, or a high-resolution radar screen can be implemented from the low-resolution radar raw image data.

100 antenna 200 transceiver
300 Display 310 A/D Conversion Module
320 Signal Processing Module 321 Pulse Integrator
323 Noise/Clutter Handler 325 Target Detector
327 Target Information Extractor 330 Target Tracking Module
340 display module
S10 Raw data extraction step S20 Pulse integration determination step
S25 Data erasing step S30 Pulse integration step
S31 interpolation processing step S33 extrapolation processing step

Claims (2)

antenna 100;
A transceiver 200 for transmitting a pulse through the antenna 100 or for receiving a radar raw image signal detected by the antenna 100 by being reflected by an object, and
As a coastal surveillance radar comprising a display 300 for displaying the received signal on a user screen,
An A/D conversion module 310 in which the display 300 matches the received radar raw image signal with azimuth information according to rotation of the antenna 100 and discretizes it at a detection distance interval set with a constant distance resolution, the discretization Signal processing module 320 for extracting target detection information after noise reduction and clutter reduction filtering on the radar raw image data, and a target tracking module 330 for linking the target detection information with a target currently being tracked or adding it as a new target ) and a display module 340 that displays the radar image output from the signal processing module 320 and the target information output from the target tracking module 330 on a user screen,
Coastal monitoring, characterized in that the signal processing module 320 determines whether to perform pulse integration according to whether there is a radar raw image signal in an azimuth range of a predetermined range based on the extracted azimuth corresponding to the row number of the radar extracted image matrix. radar.
The azimuth to extract for the radar raw image data (

) and set the extraction azimuth (

) A raw data extraction step of extracting raw image data for _{the azimuth (ACP i} ) of the radar raw image data in the azimuth region within a predetermined angle (Δθ) in the positive (+) and negative (-) directions (S10) ;
It is determined whether the number of raw data extracted in the raw data extraction step (S10) is 0, and if the number of raw data is 0, the extraction azimuth (

) to erase the data (S25) in the pulse integral determination step (S20) and
_{The minimum (ACP min} ) and maximum (ACP _max ) and extraction azimuth ( ) of the raw image data extracted in the raw data extraction step ( S10 )

), when the following [Equation 2] is satisfied, the interpolation process (S31) is performed, and when the following [Equation 4] is satisfied, the pulse integration step (S30), characterized in that the extrapolation process (S33) is performed A pulse integration method for providing a high-resolution radar image comprising a.
[Equation 2]

[Equation 4]

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