KR20090091449A - Target detection method applied in marine radar system, and record carrier, arpa board and radar using the same - Google Patents

Abstract

A method for determining a track target in a ship radar tracking system, a recording medium, an ARPA(Automatic Radar Plotting Aids) board, and a radar are provided to reduce an error of determining the target by considering the error of the position information of the target generated by the radar system. A distance and a direction from a radar antenna to a target are detected and a position of the target is measured in real time by the azimuth signal and the reception signal(S201). The speed and the course of the target are estimated using the target position information including the target and the direction(S203). A gate is installed in the estimated position of the target(S205). A line vertical to a distance axis connecting the center of the gate from the radar is obtained(S207). The target with the minimum distance among the calculated distance is chosen by calculating the distance between the new target in the line vertical to the distance axis and the gate(S209). A coordinate of the target with the minimum distance is transmitted to the target position information of the second step(S211).

Description

TARGET DETECTION METHOD APPLIED IN MARINE RADAR SYSTEM, AND RECORD CARRIER, ARPA BOARD AND RADAR USING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ship radar tracking system. More specifically, the present invention relates to a method for setting a gate for reducing processing time and reducing a processing area when tracking a target. The present invention relates to a method for reducing the possibility of selecting another target in the process of identifying whether a target was being tracked when a plurality of targets exist, and a recording medium, aparboard, and radar using the same.

In general, when tracking a target in a radar system used in a ship, it detects a signal received by the radar to select the targets and obtain the position information of the targets. The location information of one target is obtained every time the antenna rotates 360 degrees, and tracking of the target is performed based on the obtained information.

The target tracking process according to the prior art is shown in FIG. 1.

Referring to FIG. 1, in a target tracking process using a general radar, a target detection step (S101) of obtaining position information (distance, azimuth, or X and Y distances) about a target may include determining whether the target is located within a set gate. A gate comparison step S103 is performed, and a tracking target selection step S105 is performed to determine whether the targets existing in the gate are identical to the target tracked. The conventional method of determining whether the targets are identical in the target selection step is to calculate and apply the correlation between the target being tracked and the detected targets through the probability distribution of the targets. At this time, in practice, the probability distribution of the existence of the target is often not known accurately. Therefore, the method of selecting the target of the closest distance by applying the center position of the gate and the distance to the target is applied.

After the tracking target selection step, the target tracking is performed using the location information of the target selected as the same target, and the target tracking step (S107) of obtaining the speed and course information, that is, tracking information of the target is performed. At this time, the tracked result is displayed on the screen (S111), the gate installation step (S109) proceeds to the gate comparison step (S103) where the gate is installed at the position where the target is expected to be next.

2 is a diagram illustrating a method of selecting a target through a conventional distance calculation.

Referring to FIG. 2, four new targets appear in the gate, and the target closest to the center of the gate is selected and tracked by the previous target.

However, as shown in FIG. 2, the method of selecting a target by calculating a distance is basically a variance of a probability density function representing a probability distribution in which an actual target exists based on the measured position of the target in the X-axis and Y-axis directions. It can be assumed that the assumption is the same. In other words, if the variances of the probability density functions in the X-axis and Y-axis directions are different, the likelihood of selecting a target other than the tracking target increases, which is called target swap, which is called radar tracking. It is one factor that degrades performance.

3 is a target presence probability existence distribution diagram showing that a probability distribution of a target in a direction of each of the x and y axes follows a normal distribution.

According to the observation result, if the content of the target observation data follows the central limit theorem, and the x and y axes are independent of each other, the existence probability density function in the x and y axis directions of the target is assumed to be a normal distribution. Can be expressed as 2.

For each of the x and y axes as a random variable, p is the probability that the values of the random variable are x and y, m is the mean of the random variables, and σ is the standard deviation (square root of the variance). Means.

Probability density functions (p (x), p (y)) at the predicted position of the target being tracked and probability density functions (q (x), q (y)) at the position of the currently detected target are 3 and Equation 4, the correlation coefficient for the determination of the same target can be obtained using Equation 5 regarding the correlation coefficient.

Corr shows the correlation between the probability distribution of the target being tracked and the probability distribution of the currently detected target.

 Using Equations 3, 4, and 5, Equation 5 is changed to Equation 6 as follows.

In Equation 6, the center coordinates (m _px , m _py ) at the predicted position of the target being tracked and the center coordinates (m _qx , m _qy ) of the currently detected target are the average of the probability density function. However, in Equation 6, the variance of the targets (square of the standard deviation) is difficult to know exactly, and thus practical application is difficult. Therefore, the following assumptions can be applied in practice. That is, assuming that the variances of probability density in the X-axis and Y-axis directions are the same, the correlation coefficient between the two targets becomes the largest when Equation 7 below is minimum.

This means that the distance between the center coordinates of the target being tracked and the currently detected targets is minimal.

If the probability density variances in the X- and Y-axis directions are different from the above assumptions, applying the above method will result in performance degradation in selecting the exact same target, increasing the likelihood of target swapping. There are disadvantages.

Accordingly, the present invention is to solve the problems of the prior art as described above, it is possible to determine whether the target is the same in consideration of the error of the position information of the target measured by the radar system to track compared to the conventional method We want to improve the likelihood of selecting another target in the process of determining whether it is a target that was in use.

In order to achieve the object of the present invention as described above, in accordance with a feature of the present invention, the tracking target determination method using a ship radar, measuring the position of the target in real time through the azimuth and received signals of the radar and radar Detecting a distance and orientation from the antenna to the target; A second step of predicting the speed and course of the target by tracking the movement of the target by using the target position information; A third step of installing a gate at a location point where a target is expected to be at the predicted next detection time point; A fourth step of obtaining a straight line perpendicular to the distance axis, which is a straight line connecting the gate center from the radar antenna; Calculating distances between a straight line perpendicular to the distance axis and newly detected targets at the gate for targets entering the gate at a next detection time and selecting a target having a minimum distance among the calculated distances. 5 steps; The sixth step of transferring the coordinates of the target having the predetermined minimum distance back to the target position information of the second step is repeated, and the process from the second step to the sixth step is repeated.

According to another aspect of the invention, the computer-readable recording medium, the first step of measuring the position of the target in real time through the azimuth signal and the received signal of the radar and detecting the distance and orientation from the radar antenna to the target (S201) ); A second step (S203) of predicting the speed and course of the target by tracking the movement of the target by using target position information including the target and the orientation; A third step (S205) of installing a gate at a location point where a target is expected to be at the predicted next detection time point; A fourth step (S207) of obtaining a straight line perpendicular to a distance axis that is a straight line passing through the center of the installed gate and connecting the gate center from the radar; Calculating distances between a straight line perpendicular to the distance axis and newly detected targets at the gate with respect to targets entering the gate at a next detection time and selecting a target having a minimum distance among the calculated distances. Step 5 (S209); And a sixth step S211 in which coordinates of the target having the predetermined minimum distance are transferred back to the target position information of the second step, wherein the ship radar in which the processes from the second step to the sixth step are repeated is repeated. The tracking target determination algorithm of the tracking system used is recorded.

According to another feature of the invention, an automatic radar positioning (ARPA) board is operated by the above computer readable recording medium.

According to still another aspect of the present invention, a radar includes: an antenna that radiates high frequency into the air and receives reflected waves reflected from a target; A transceiver for generating the high frequency; A processing unit for processing the reflected wave from the antenna; A first step of measuring the position of the target in real time through the azimuth and received signals of the radar and detecting a distance and a direction from the radar antenna to the target; A second step of predicting the speed and course of the target by tracking the movement of the target by using target position information including the target and the orientation; A third step of installing a gate at a location point where a target is expected to be at the predicted next detection time point; A fourth step of obtaining a straight line perpendicular to a distance axis that is a straight line passing through the center of the installed gate and connecting the gate center from the radar; Calculating distances between a straight line perpendicular to the distance axis and newly detected targets at the gate with respect to targets entering the gate at a next detection time and selecting a target having a minimum distance among the calculated distances. 5 steps; And a sixth step of transmitting the coordinates of the target having the predetermined minimum distance back to the target position information of the second step, wherein the tracking target determination algorithm is repeated. A controller configured to carry out a function of tracking a target; An interface board for receiving a bearing and speed information of the ship, an electronic chart and navigation record information of the ship, and transmitting a signal between the processing unit and the control unit; A monitor for displaying information of the controller; And an input device for inputting a command and data to the controller.

According to the method, the computer readable recording medium, the apa board, and the radar presented in the present invention, in the process of confirming whether the target was being tracked compared to the conventional method, the measurement error in the axial direction is different, so that the target is asymmetric in each axis direction. Targets other than tracking targets are selected during the target selection process when they have a probability distribution, i.e., when the variance in one direction becomes larger than the variance in the other direction in the probability density function of each axis with a normal distribution characteristic. This has the advantage of significantly lowering the likelihood of doing so.

In order to fully understand the present invention, the advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings which illustrate preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

The main point of the present invention is to provide a method of selecting the same target by using the feature that the measurement error in the azimuth direction is generally larger than the error in the distance axial direction.

In addition, as will be described again below, in the present invention, it is assumed that the variance in the probability density function at the predicted position of the target being tracked is equal to the variance in the probability density function of the currently detected target. It is assumed that the variance of the probability distributions present is significantly larger than the variance of the probability distribution in the distance axis direction.

4 is a view showing the coordinates of the target, the distance axis and the azimuth axis in the radar according to the present invention.

The coordinate of the target according to the present invention is represented by the distance axis from the radar to the target and the azimuth axis perpendicular to the distance axis, rather than the coordinate system represented by the conventional x and y axes shown in FIG. 2.

The radar system applied to ships measures the distance and azimuth of the target by emitting radio waves while the antenna called the scanner rotates 360 degrees. Therefore, the measurement errors appear in the distance direction and the azimuth direction and are independent of each other.

FIG. 5 illustrates a target presence probability presence distribution diagram illustrating a probability distribution in which a target exists along the distance axis and the azimuth axis of FIG. 4.

The existence probability distribution of a target having a center coordinate of (r, θ) can be obtained by applying a method similar to Equations 1 and 2 as follows. At this time, the unit of azimuth axial coordinate θ is radian, and the unit of distance axial coordinate r is nautical mile.

For each distance and azimuth from the center as a random variable, p is the probability that the values of the random variables are r and θ, m is the mean of the random variables, and σ is the standard deviation (square root of the variance). ).

In order to select a target through correlation in two axes, the units need to be matched. When an error by θ occurs, the distance error (r _θ ) in the azimuth direction has the following relationship.

Using Equations 9 and 10, the distance error probability p (r _θ ) in the azimuth direction can be obtained as Equation 11 below.

FIG. 6 is a diagram showing a target position probability distribution in a prediction position coordinate of a target being tracked and a coordinate of a currently detected target, their respective distance axes and azimuth axes.

As shown in FIG. 6, the predicted position of the tracking target having the center coordinates (m _pr , m _{p θ} ) and the existence probability distribution of the currently detected target having the center coordinates of (m _qr , m _{q θ} ) are represented by Equations 12 and 8, respectively. Suppose that it is represented by 13, using the definition of equation (5) can be obtained by the equations (14) and (15), which are correlations between the distance axis and the azimuth axis.

Since the distance axis and the azimuth axis are orthogonal to each other and independent, the correlation between the two targets is represented by the sum of Equations 14 and 15.

In order to obtain the correlation using Equation 16, it is necessary to know the variance and the mean of the probability density function in each axial direction. The average over each axis is easily obtained by being the center position of the targets measured by the radar, but the variance is generally difficult to know. Therefore, the following assumptions about variance are necessary for the identification of the same target.

Assumptions 1. The variance in the probability density function of the target being tracked and the variance in the probability density function of the currently detected target are the same as in Equation 17.

In the course of tracking the target, the predicted position of the target being tracked and the position of the currently detected target are the time when the radar scanner is rotated by one turn (less than about 3 seconds), so the characteristics of the target will not change significantly. It can be called a home. Based on hypothesis 1, Equation 16 is rearranged as follows.

Radar applied to ship has a backlash caused by antenna gear, radar tilt due to rolling or pitching of ship, output error of gyro, azimuth measurement sensor, random error and sampling error. As the distance error factors, there are radar slope and sampling error due to rolling. Therefore, it is generally reported that the error factor due to the azimuth angle is large. This makes the following assumptions.

Assumption 2. As shown in Equation 19, the variance of the direction axial probability distribution that is perpendicular to the target direction in the radar is considerably larger than the variance of the distance axial probability distribution that is the target direction in the radar.

Using hypothesis 2, it can be seen that the first term of the right side has the greatest influence on the correlation coefficient in the correlation coefficient of Equation 18.

In other words, the correlation coefficient between the two targets means that the distance in the distance direction increases when the distance is close.

In this patent, in order to utilize this fact, the following method is used to determine whether the target being tracked is the same.

Hereinafter, a method of obtaining a distance that is the basis of target selection will be described with reference to FIG. 7.

7 is a diagram illustrating a process of selecting a target having a minimum distance by calculating a distance between a target and a straight line passing through the center of the gate and perpendicular to the distance axis.

In the process of tracking, if the predicted position of the track to be tracked, that is, the center of the gate is installed at the position (r, θ), a straight line (ax + by + c = 0) perpendicular to the distance axis passing through the center of the gate is given by the following equation. You can get it together.

The distance d _i from the center coordinates (x _i , y _i ) of any target in the gate to the straight line passing through the center of the gate and perpendicular to the distance axis is expressed by the following equation.

Obtain and d _i for all of the target within the gate by the expression (21) such that the value of d _i is selected for the smallest target. The coordinates of the selected target are passed back to the step of tracking the movement of the target and repeat the process. By applying this method, the target is selected by considering the sensor characteristics of the radar itself, so that the possibility of target exchange during the tracking process can be reduced, resulting in better tracking performance.

Hereinafter, a target tracking method using a ship radar according to the present invention will be described.

8 is a flowchart illustrating a target tracking method using a ship radar according to the present invention.

In the target tracking method using the ship radar according to the present invention, first, the position of the target is measured in real time through the azimuth signal and the received signal of the ship radar, and the distance and azimuth from the radar antenna to the target are detected (S201). The method for detecting the distance and azimuth from the radar antenna to the target uses a conventionally known technique, and thus the specific method is omitted.

Then, by using the target position information to track the movement of the target to predict the speed and course of the target (S203). Tracking the movement of the target refers to identifying how the target is moving using measurements of distance and azimuth from the radar antenna recorded in real time in this step. In other words, the distance between the current target coordinates or the radar antenna and the current target coordinates and the measured values of the distance and the direction measured in real time and the difference between the measured values of the distance and the orientation is calculated (the current measured value-the past measured value) Displacement can be obtained.) By obtaining data on the direction and speed of the target, you can identify the target's movement and track the target. Thus, you can predict the speed and course of the target immediately after.

Then, the gate is installed at the position point where the target is expected to be at the next detection time point through the tracked result (S205). The method of installing the gate is to install a new gate using the coordinates of the target tracked and predicted as the center coordinates of the gate, and the targets can be detected again in the gate.

Then, a straight line perpendicular to the distance axis is obtained while passing through the center of the installed gate (S207). As shown in FIG. 7, the distance axis of the target refers to a straight line passing through the center of the radar antenna and the gate, that is, the predicted coordinates of the target, and a virtual straight line passing through the center of the gate perpendicular to the target is determined singly. This is indicated by the azimuth axis in FIGS. 4 to 7.

Then, the distance between the straight line and the target is calculated for the targets entering the gate at the next detection time, and the target having the minimum distance is selected (S209). More specifically, as shown in FIG. 7, the distance between the coordinates of the targets and the straight line in the direction of the azimuth axis perpendicular to the distance axis is calculated based on the straight line passing through the center of the gate and perpendicular to the distance axis in this step. The distance between the coordinates of the target and the straight line in the azimuth direction passing through the target can be obtained using Equation 21.

Then, the target having the closest distance among the obtained distances is selected as the same target as the existing target is moved (S211). This step has the effect of reducing the probability of false recognition of the target.

The coordinates of the selected target are passed back to the step of tracking the movement of the target and the process is repeated. In other words, the coordinates of the target selected as the same target are regarded as the coordinates of the measured target, the distance and azimuth measurement, the installation of a new gate, the virtual straight line, the distance from the newly detected targets are calculated from the straight line. Repeat the selection process and continue to identify targets.

The target tracking method as described above can be used in the case where the target presence probability distribution is asymmetrical due to the difference of axial error factors during the tracking process, and the target position is measured by azimuth and distance such as coastal radar or ship radar. In the system, when there is an error factor having a relationship as shown in Equation 10, according to the relationship as shown in Equation 10, as the distance r increases, the error distance r _θ in the azimuth axis direction increases, When the variance becomes larger than the direction of the distance axis so that the variance of the probability distribution appears asymmetrically, the target tracking method according to the present invention can be applied when the position of the target is to be measured and the tracking is performed.

Such an algorithm of the target tracking method may be produced by a computer program and stored in a computer-readable recording medium for use. In addition, the target tracking algorithm according to the present invention can be loaded into a computer or server that is manufactured by a computer program to control the radar or track the target of the radar. In addition, it may be manufactured as a separate radar target tracking device equipped with the target tracking algorithm of the present invention.

9 is a block diagram of a radar equipped with a target tracking algorithm according to the present invention.

9, the radar according to the present invention includes an antenna 901, a transceiver 902, a processing unit 903, an interface board 904, a PC 905, a monitor 906, a keyboard 907, and a sensor. 908, ECDIS 909, and VDR 910.

The antenna 901 radiates the high frequency generated by the transceiver 902 to the air, and the processing unit 903 processes the reflected wave coming from the antenna, that is, the reflected wave reflected from the target. The interface board 904 transmits a signal between the processing unit 903 and the PC 905 and receives information from the sensor 908, the ECDIS 909, and the VDR 910. Sensor 908 detects azimuth and speed information of a ship, etc., ECDIS (Electronic Chart Display and Information System) 909 is an electronic chart and information display device, VDR (Voyage Data Recorder) 910 is a black box of the aircraft It is a navigation recorder that records and saves the main navigation data related to the ship's operation such as ship's position / speed / date and time as well as various conversations and communication in radar image / helm.

The PC 905 (or control unit) includes a remote service console board (RSC board) 911, an automatic radar plotting aids (ARPA) board 912, a graphics board 193, and the like, and an automatic radar positioning display. The (ARPA) board 912 is equipped with a target tracking determination algorithm of a ship radar according to the present invention to perform a function of tracking a target.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. . Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a flowchart illustrating a target tracking process according to the prior art.

2 is a diagram illustrating a method of selecting a target through a conventional distance calculation.

3 is a target existence probability existence distribution diagram indicating that a probability distribution in which targets exist on x and y axes follows a normal distribution.

4 is a view showing the coordinates of the target, its distance axis and azimuth axis in the radar according to the present invention.

5 is a target existence probability existence distribution diagram illustrating a probability distribution in which a target exists along the distance axis and the azimuth axis of FIG. 4.

6 is a diagram showing the coordinates of the predicted position of the target being tracked and the coordinates of the currently detected target, their respective distance axes and azimuth axis distributions.

7 is a diagram illustrating a process of selecting a target having a minimum distance by calculating a distance between a target and a straight line passing through the center of the gate and perpendicular to the distance axis.

8 is a flowchart illustrating a target tracking method using a ship radar according to the present invention.

9 is a block diagram of a radar equipped with a target tracking algorithm according to the present invention.

Claims (14)

In the tracking target determination method using a ship radar, A first step (S201) of measuring a position of a target in real time based on the azimuth and received signals of the radar and detecting a distance and a direction from the radar antenna to the target; A second step (S203) of predicting the speed and course of the target by tracking the movement of the target by using target position information including the target and the orientation; A third step (S205) of installing a gate at a location point where a target is expected to be at the predicted next detection time point; A fourth step (S207) of obtaining a straight line perpendicular to a distance axis that is a straight line passing through the center of the installed gate and connecting the gate center from the radar; Calculating distances between a straight line perpendicular to the distance axis and newly detected targets at the gate with respect to targets entering the gate at a next detection time and selecting a target having a minimum distance among the calculated distances. Step 5 (S209); And The ship radar tracking system including a sixth step (S211) that the coordinates of the target having the predetermined minimum distance is transmitted back to the target position information of the second step and the process from the second step to the sixth step is repeated. Tracking target determination method. The method of claim 1, The second step, Calculating a difference between the coordinates of the current target with respect to the measured value of the distance and orientation from the radar antenna to the current target coordinates and the past target coordinates with respect to the measured values of the previously measured distance and orientation; Calculating data about a direction and a speed of the target; And Identifying the movement of the target to predict the speed and course of the subsequent target. The method of claim 1, The fourth step is the following equation

Where the center coordinate of the gate is (r, θ), Obtaining a straight line perpendicular to the distance axis, wherein the vertical straight line is represented by ax + by + c = 0. The method of claim 3, wherein The fifth step is the following equation

Here, coordinates (x _i , y _i ) are the coordinates of the center of any target in the gate, Calculating a distance d _i and selecting a target having the smallest distance among the calculated distances. The method of claim 1, The target estimation method is a tracking target determination method of a ship radar tracking system, characterized in that the variance in the probability density function of the target being tracked and the variance in the probability density function of the currently detected target are assumed to be the same. . The method of claim 5, wherein In the target estimation method, the tracking target determination of the ship radar tracking system is characterized in that the probability densities in each axial direction having a normal distribution feature are assumed to be relatively large in variance in one direction compared to the variance in the other direction. Way. A computer-readable recording medium in which a tracking target determination algorithm of a tracking system using a ship radar is recorded. A first step (S201) of measuring a position of a target in real time based on the azimuth and received signals of the radar and detecting a distance and a direction from the radar antenna to the target; A second step (S203) of predicting the speed and course of the target by tracking the movement of the target by using target position information including the target and the orientation; A third step (S205) of installing a gate at a location point where a target is expected to be at the predicted next detection time point; A fourth step (S207) of obtaining a straight line perpendicular to a distance axis that is a straight line passing through the center of the installed gate and connecting the gate center from the radar; Calculating distances between a straight line perpendicular to the distance axis and newly detected targets at the gate with respect to targets entering the gate at a next detection time and selecting a target having a minimum distance among the calculated distances. Step 5 (S209); And And a sixth step S211 in which the coordinates of the target having the predetermined minimum distance are transferred back to the target location information of the second step, and the processes from the second step to the sixth step are repeated. A computer readable recording medium recording a tracking target determination algorithm of a tracking system using a ship radar. The method of claim 7, wherein The second step, Calculating a difference between the coordinates of the current target with respect to the measured value of the distance and orientation from the radar antenna to the current target coordinates and the past target coordinates with respect to the measured values of the previously measured distance and orientation; Calculating data about a direction and a speed of the target; And And identifying the movement of the target to predict the speed and course of the subsequent target. The computer-readable recording medium having recorded thereon a tracking target determination algorithm of a tracking system using a ship radar. The method of claim 7, wherein The fourth step is the following equation

Where the center coordinate of the gate is (r, θ), A computer-readable recording medium in which a tracking target determination algorithm of a tracking system using a ship radar is recorded, wherein a straight line perpendicular to the distance axis is obtained, and the vertical straight line is represented by ax + by + c = 0. . The method of claim 9, The fifth step is the following equation

Here, coordinates (x _i , y _i ) are the coordinates of the center of any target in the gate, Through the distance (d _i) to calculate and output the distance to the target tracking algorithm determines that the computer-readable recording medium recording a tracking system using a vessel radar which is characterized in that selection of the target having the smallest distance of the. The method of claim 7, wherein The target estimation method is a tracking target of a tracking system using a ship radar, characterized in that the variance in the probability density function of the target being tracked and the variance in the probability density function of the currently detected target are assumed to be the same. A computer-readable recording medium having a decision algorithm recorded thereon. The method of claim 11, The target estimation method tracks a tracking system using a ship radar, wherein the probability densities in each axial direction having a periodic distribution characteristic are assumed to be relatively large in variance in one direction than in the other direction. Computer-readable recording medium having a target determination algorithm recorded thereon. 13. An automatic radar positioning board (ARPA) board comprising a control unit operated by a computer readable recording medium according to any one of claims 7 to 12. An antenna that radiates high frequency into the air and receives reflected waves reflected from the target; A transceiver for generating the high frequency; A processing unit for processing the reflected wave from the antenna; A first step of measuring a position of a target in real time through the azimuth and received signals of the radar and detecting a distance and a direction from the radar antenna to the target; A second step of predicting the speed and course of the target by tracking the movement of the target by using target position information including the target and the orientation; A third step of installing a gate at a location point where a target is expected to be at the predicted next detection time point; A fourth step of obtaining a straight line perpendicular to a distance axis that is a straight line passing through the center of the installed gate and connecting the gate center from the radar; Calculating distances between a straight line perpendicular to the distance axis and newly detected targets at the gate with respect to targets entering the gate at a next detection time and selecting a target having a minimum distance among the calculated distances. 5 steps; And a sixth step of transmitting the coordinates of the target having the predetermined minimum distance back to the target position information of the second step, wherein the tracking target determination algorithm is repeated. A controller configured to carry out a function of tracking a target; An interface board for receiving the azimuth and speed information of the ship, the electronic chart and navigation record information of the ship, and transmitting a signal between the processing unit and the control unit; A monitor for displaying information of the controller; And Radar including an input device for inputting commands and data to the control unit.

Images