KR100795497B1 - Wave measure method and system using radar - Google Patents

Abstract

A wave measuring system and a method using a radar are provided to secure convenience and accuracy for users by observing the wave of a region that is not disturbed by the ships and to observe the waves regardless of night and day, and bad weather. In a wave measuring system using a radar(100), the radar detects obstacles of the sea, other ships, and the seaside by checking objects that exist within a predetermined range of the moving ship and provides a radar image by using a radar image signal and trigger, heading, and bearing signals. A wave measuring server(200) selects at least one analysis region in the radar image signal provided from the radar, calculates a main direction of the wave for each analysis region, determines the analysis region corresponding to the signal level and main direction of the wave, and processes wave information of the synthesized spectrum and tidal information by calculating and synthesizing wave information for each analysis region.

Description

Wave measurement method and system using radar {Wave Measure Method And System Using Radar}

1 is a view showing a wave measurement system using a radar according to the present invention.

2 is a flow chart showing a wave measurement method using a radar according to the present invention.

3 is a flowchart illustrating a subroutine process for calculating a direction wave spectrum for each analysis region according to the present invention.

4 is a graph showing a traveling direction and a frequency of a wave according to the present invention;

<Explanation of symbols for the main parts of the drawings>

100: radar 200: blue measurement server

201: GPS 203: Gyro

205: communication unit 207: digital signal conversion unit

The present invention relates to a wave measurement system and method using a radar, and more particularly, to determine an analysis region in a provided radar image, calculate a direction wave spectrum for each analysis region, and use a radar for more accurate wave observation. A wave measurement system and method.

In general, waves are a very important environmental factor in marine vehicles and offshore structures. Wave measurements have been performed for a long time in order to calculate safety, system operation, and design criteria.

In the past, wave measurement was mainly performed by the neck side, and the development of measurement-related techniques has led to the development of negative and vertical surface displacement measurement systems using acceleration sensors and ultrasonic sensors.

Recently, buoys using GPS have been developed.

This conventional wave measurement system is characterized by measuring the surface displacement in a fixed position, it has a disadvantage that can not be applied when the position is constantly changing, such as a ship, maintenance of equipment is essential There is a high probability of loss due to bad weather or theft.

For this reason, the wave measurement on ships is mainly based on visual observation. However, the reliability of the observation is greatly affected by the observer's skill, and the reliability of the observation is problematic due to the difficult lighting at night.

As a conventional technique, a marine state measurement system for measuring a relative wave in real time using an ultrasonic distance measuring sensor to a bow of a ship operating at sea is disclosed in Korean Unexamined Patent Publication No. 1996-29169. According to the state measurement system, a method of calculating the actual wave in the athlete by calculating the relative movement of the athlete based on the movement data of the hull obtained by using the inertial navigation sensor, the characteristics of the ship through the movement of the hull obtained using the sensor In order to compensate for inaccurate motion due to disturbance and disturbance, calculation using a microprocessor is performed, but a problem arises that correction of the ultrasonic sensor output is required according to the movement of the ship. Type sleep displacement meter provides a narrow range of images There are difficult issues, as well as to provide tidal get a series of images were generated.

In addition, the relative surface displacement measurement system using ultrasonic waves or electromagnetic waves in the bow portion as described above does not efficiently compensate for the effects such as the diverging wave due to the ship motion and the reflection of the incident wave by the ship and bulbs applied to large merchant ships Depending on the presence of), the installation is difficult and the application results are insignificant due to problems such as unknown information on the direction of the wave.

In order to solve the above problems, the present invention solves the mobility problem of the fixed surface displacement displacement system by calculating the direction wave spectrum for each analysis region by performing the wave measurement using the navigation radar, It is an object of the present invention to provide a wave measurement system and method using a radar that provides more accurate wave observation by solving the disturbance problem of a wave system caused by a ship having a relative surface displacement measurement system.

In order to achieve the above object, the wave measurement system using the radar according to the present invention detects obstacles (marine structures, etc.), other vessels, coasts, etc. at sea by identifying objects within a certain range of the vessel in operation, radar A radar (Radar. 100) for providing a radar image using an image signal, a trigger, a heading, and a bearing signal; And selecting an arbitrary analysis area of any number of radar image signals provided from the radar to calculate the main direction of the blue wave for each analysis area, and determine the analysis area according to the signal level and the main direction of the blue wave. And a wave measurement server 200 for calculating and synthesizing the direction wave spectrum for each analysis region to process the wave and bird information of the synthesized spectrum.

In addition, the method for measuring the blue wave using the radar according to the present invention comprises the steps of (a) inputting any one of the radar signal, the RGB signal of the radar or the photographing signal result of the radar image to implement a radar image; (S10) (c) (S30) (d) determining an analysis region and calculating direction wave spectra for each analysis region by selecting an analysis region by a predetermined number using the implemented radar image; (S50) (e) synthesizing the directional wave spectra for each analysis region; (S60) and (f) processing the blue and tidal current information in the synthesized spectrum (S70).

Hereinafter, with reference to the accompanying drawings there may be a plurality of embodiments of the blue measurement system and method using a radar according to the present invention, the following describes the most preferred embodiment.

1 is a view showing a wave measurement system using a radar according to the present invention.

As shown in FIG. 1, the wave measurement system using the radar according to the present invention detects obstacles (marine structures), other vessels, coasts, and the like by identifying objects within a certain range of a vessel in operation, and radar images. Any number of radar image signals provided from the radar (Radar, 100) and radar (Radar) that provide radar images using signals, triggers, heading, and bearing signals Calculate the main direction for each analysis area by selecting the area, determine the analysis area according to the signal level and the main direction, calculate and synthesize the direction wave spectrum for each analysis area, and process the wave information and tidal wave information of the synthesized spectrum. It consists of the blue measurement server 200.

Radar 100 is a radar device designed specifically for use in ships in consideration of such conditions of use, and detects obstacles (marine structures, etc.), other ships, coasts, etc. at sea and their position and distance from their ships, Display the direction above the Plane Position Indicator (PPI).

The PPI image of the radar 100 represents the time and direction taken by the signal irradiated from the radar antenna to return to the sea level, and the signal magnitude at that time. The height of the sea level does not quantitatively indicate the period of the wave. It contains information closely related to the height, height, and direction of travel.

In addition, the PPI image of the radar 100 provides a wide range of spatial information, unlike other measurement equipment (buy, vertical surface displacement meter system, etc.) and also obtains temporal information when a continuous image is obtained. Can be.

In addition, the radar 100 identifies objects within a certain range of the vessel currently in operation, and supports signal processing and display of the radar video.

The radar 100 generally uses a pulse radar that displays a target in a plane at a relative position using a frequency of 3 GHz, 5 GHz, or 9 GHz, where the radar 100 detects a distance from near to far. However, one of the radars to be installed in accordance with the ship safety law should be 9GHz band in principle, and X-Band Radar is mainly used in the present invention.

The radar 100 may include at least one of a method of implementing a radar image through a radar signal, a method of implementing a radar image using an RGB signal of a radar, and a method of implementing a radar image using a photographing result of the radar image. The radar image is implemented through one method.

The blue measurement server 200 selects an arbitrary number of analysis areas for the radar image signal provided from the radar, calculates main directions for each analysis area, and determines an analysis area according to the signal level and the main direction. The direction wave spectrum of each analysis area is calculated and synthesized to process the wave and tidal wave information of the synthesized spectrum.

The blue measurement server 200 is a GPS 201 for positioning and navigating a ship in navigation, a Gyro 203 for measuring azimuth of a ship, a communication unit 205 for receiving the GPS information, and information on the Gyro A digital signal converter 207 for receiving a signal and converting it into a digital signal, an input unit 211 for receiving image information and a radar signal through the communication unit and the digital signal converter, and radar signal information and image information input through the input unit. A calculation unit 215 for calculating an arbitrary analysis region using the calculation unit and calculating a spectrum through integration in a frequency domain, a storage unit 217 for storing information calculated for each analysis region calculated by the calculation unit, and The navigation state display unit 219 which displays the operation status of the ship using the information stored in the storage unit and the provided radar image signal may select an arbitrary number of analysis areas. For example , the control unit 213 may be configured to calculate a main direction for each selected analysis area to determine an analysis area, and to process the blue and tidal current information by synthesizing the blue information for each analysis area calculated by the calculation unit.

GPS (Global Positioning System) 201 provides the position of the vessel, the number of revolutions (rpm) of the engine of the vessel, the information for determining the position of the vessel in sailing and setting the route, the speed of the vessel through the communication unit 205 to be described later Provides information for measuring

Gyro (Gyro. 203) is a device for measuring the azimuth angle of the ship, automatically compensates for errors due to the fluctuations of the ship, to detect the direction of the ship to provide information about the direction of the progress, the information Is converted through the digital signal converter 207, which will be described later.

The input unit 211 receives radar image information through the communication unit 205 and the digital signal converter 207.

The input unit 211 implements a radar image by receiving a radar signal through the radar, a method of implementing a radar image using an RGB signal of a radar, and implementing a radar image using a photographing result of the radar image. At least one piece of information is entered.

The calculator 215 selects an arbitrary analysis region using the radar image implementation information input through the input unit, performs a Fast Fourier Transform (hereinafter, abbreviated as FFT), and calculates a corresponding spectrum.

The Fast Fourier Transform (hereinafter, abbreviated as FFT) is a general name of an algorithm used to transform a signal expressed in time domain into a frequency domain, and orthogonal frequency division multiplexing using the FFT algorithm Division Multiplexing (OFDM) is used for digital signal processing and real time signal processing such as radar signal processing and spectrum analysis.

The calculator 215 divides the data block through a calculation step by the following equations through the FFT algorithm.

The storage unit 217 stores information calculated for each analysis region calculated by the calculation unit 215.

That is, the storage unit 217 stores the data calculated through the FFT algorithm, the information according to the wave direction and wave energy, statistical distribution information according to the existing calculation result, analysis information and wind direction in the same direction as the wind direction The analysis information is stored according to the difference of 90 degrees from.

The operation information display unit 219 displays the operation state of the ship by using the information stored in the storage unit.

The controller 213 controls each unit, implements a radar image using a radar signal, and controls bird estimation and filtering.

The controller 213 selects an analysis area of any number of radar images provided from the radar, calculates a main direction for each selected analysis area, determines an analysis area, and calculates each analysis area calculated through the calculation unit. The star direction wave spectrum is synthesized and controlled to process wave information and bird information.

2 is a flowchart illustrating a wave measurement method using a radar according to the present invention.

As shown in FIG. 2, any one of a radar signal, an RGB signal of a radar, or a photographing signal result of a radar image is input to implement a radar image.

In the step S10, the blue measurement server receives an image captured by the radar device, at this time, the image is received from the radar device using the radar signal, or the radar image is provided using the radar signal of the radar device, or The radar image may be implemented by selecting at least one method of receiving a radar image by using the photographing result.

The PPI image of the implemented radar shows the time and direction taken by the signal irradiated from the radar antenna to return to the sea level, and the signal size at that time. In addition to providing spatial information, the temporal information can be obtained by obtaining continuous images.

The radar signal basically includes a radar image signal, a trigger, a heading, or a bearing signal provided by the radar.

Next, in order to sample the implemented radar image, the blue measurement server selects an analysis region as many as the corresponding radar image (S20), and calculates a power spectrum to calculate a main direction for each analysis region. (S30)

Steps S20 through S30 select a portion of the radar image as an analysis region to construct a power spectrum through a fast Fourier transform for transforming a signal expressed in the time domain into a frequency domain. .

The above steps configure the power spectrum using the FFT through a single PPI image received from the radar.

The power spectrum calculated using the FFT is described in Equation 1.

[Equation 1]

는 PPI 영상의 신호 크기, kx, ky 는 x축, y축 방향의 파수이다. here,

Is the signal magnitude of the PPI image, kx, ky are the wave numbers in the x-axis and y-axis directions.

Next, the wave measurement server determines an analysis region and calculates a direction wave spectrum for each analysis region (S50).

The step S50 will be described in detail with reference to FIG. 3.

Next, the wave measurement server synthesizes a region-specific spectrum (S60), and calculates and processes various wave information and bird information from the direction wave spectrum (S70).

In this case, when the blue measurement system using the radar is applied to the ship in motion, the step of reconstructing the radar image using the ship's ship speed, azimuth information is added.

3 is a flowchart illustrating a subroutine process for calculating a direction wave spectrum of each analysis region according to the present invention.

As shown in FIG. 3, the wave measurement server calculates the direction wave spectrum for each analysis region by first determining the analysis region by the wave measurement server (S51).

The determination of the analysis region in the step S51 is to determine one or two analysis regions according to the wave direction and wave energy, or to determine the analysis region using the statistical distribution of the existing calculation results, or 90 degrees in the same direction and wind direction Select at least one of the interpretation areas in case of differences.

Next, the 3D FFT is performed on continuous radar image data corresponding to the analysis region selected by the blue measurement server to obtain a 3D image spectrum (S52).

In the step S52, when the power spectrum of Equation 1 is used to calculate the 3D image spectrum, the calculated power spectrum includes wave components and noise signal components. The image spectral values from which the other components are removed are described in Equation 2.

[Equation 2]

는 선속,

는 조류 등에 의한 해수면의 이동속도이다. Where g is gravity acceleration, d is depth,

The speed of the ship,

Is the speed of sea level movement by algae and the like.

In this case, the 3D FFT refers to a 3D fast Fourier transform that performs a Fourier transform at a high speed on a noise value to be erased to obtain necessary image data values other than noise from an input PPI image, and the 3D image spectrum is the 3D FFT. Refers to the spectrum of the video image obtained through.

Next, the wave measurement server performs filtering and tidal velocity estimation by applying dispersion relations according to the ship speed, azimuth angle, and wave period and direction using the image spectrum value. )

)를 나타내고, 그 값이 수학식 3에 기재되어 있다. The velocity of the tidal current is a value that minimizes an error between the frequency at which energy is distributed in the 3D FFT result and the frequency calculated in Equation 2, and the tidal velocity (

), And its value is described in equation (3).

[Equation 3]

이고,Where the error range of the frequency

ego,

이고,

The conditional expression to have minimum value by applying least squares method for Cx Cy

ego,

to be.)

In this case, in order to overcome the ambiguity of the direction to the power spectrum described in Equation 1, Equation 4 may be obtained by integrating only the positive frequency region in the power spectrum of the wave number separated by frequency (Equation 1).

[Equation 4]

Next, the wave measurement server calculates a direction wave spectrum by applying a correlation analysis result between the signal to noise ratio (SNR) of the image spectrum and the actual wave. (S55)

The wave measurement server may be calculated by Equations 1 to 4 to obtain a direction wave spectrum based on the propagation direction and frequency of the wave.

The direction wave spectrum is described in Equation 5, and a graph of a traveling direction and a frequency of a corresponding wave is shown in FIG. 4.

[Equation 5]

이고,

는 실험과 수치 시뮬레이션을 통해 얻을 수 있는 상수이다.Here, the process of converting the power spectrum described in Equation 4 into the power spectrum for wave height is calculated using MTF (Modulation Transfer Function),

ego,

Is a constant that can be obtained through experiment and numerical simulation.

Through the above process, the direction wave spectrum of the wave propagation direction and frequency is obtained, the corresponding graph is calculated, the propagation direction simulation of the wave is derived, and the sea wave height is predicted using the induced simulation to operate the ship. .

In addition, the wave measurement system using the radar corresponds to one-third of the wave height in the order of the highest wave among the waves generated for a certain time from the direction wave spectrum by applying the correlation analysis result between the wave height and the signal to noise ratio (SNR) of the spectrum. You can also calculate the significant wave height by averaging the wave heights up to the mean, and calculate the period, wave direction, etc. for the significant wave height.

The radar measurement system and method using the radar which concerns on this invention were demonstrated above. Such a technical configuration of the present invention will be understood by those skilled in the art that the present invention can be implemented in other specific forms without changing the technical spirit or essential features of the present invention.

Therefore, the above-described embodiments are to be understood in all respects as illustrative and not restrictive, and the scope of the present invention is indicated by the appended claims rather than the foregoing description, and the meanings of the claims and All changes or modifications derived from the scope and the equivalent concept should be construed as being included in the scope of the present invention.

The present invention as described above is able to measure the wave even in a moving ship, it is possible to observe the breakdown of the area not disturbed by the ship has the effect to provide safety and convenience to the user to provide safety.

In addition, the present invention, unlike the visual observation, because the measurement is performed by the system is an observation result is objective, there is an effect to increase the safety and economic efficiency of the ship by enabling the observation regardless of day and night and bad weather.

Claims (10)

Identify objects within a certain range of the vessel in operation to detect obstacles at sea, other vessels, coasts, etc. and provide radar images using radar image signals, triggers, headings and bearing signals. Radar 100; And The radar image signal provided from the radar is selected to calculate one or more analysis regions to calculate the main direction of the blue waves for each analysis region, and determine the analysis region according to the signal level and the main direction of the blue to obtain the blue information for each analysis region. A blue measurement server 200 for calculating and synthesizing and processing the blue information and the bird information of the synthesized spectrum; Blue measurement system using a radar, characterized in that consisting of. The method of claim 1, The blue measurement server 200, A GPS (GPS) 201 which provides information about a ship's position and route setting; A gyro (Gyro, 203) which measures the azimuth of the vessel and detects the traveling direction of the vessel; A communication unit 205 for receiving information of the GPS; A digital signal converter 207 which receives the information of the Gyro and converts the information into a digital signal; An input unit 211 which receives image information and a radar signal through the communication unit and the digital signal converter; A calculation unit 215 for calculating an arbitrary analysis region using radar signal information and image information input through the input unit and calculating a spectrum through integration in a frequency domain; A storage unit 217 for storing the data calculated by the calculation unit and storing the information according to the wave direction and the wave energy, statistical distribution information according to the existing calculation result, and analysis information according to the direction difference between the wind direction; A navigation information display unit 219 for displaying a navigation status of the ship using the information stored in the storage unit; And The radar image signal input through the input unit is controlled to select one or more analysis regions, the main direction of the blue waves for each selected analysis region is calculated to determine an analysis region, and the blue information for each analysis region calculated by the calculation unit is calculated. A controller 213 for synthesizing and processing blue information and bird information; Blue measurement system using a radar comprising a. The method of claim 1, The radar 100 is, Blue measurement system using a radar, characterized in that the X-Band Radar (X-Band Radar). (a) selecting at least one of a radar signal, an RGB signal of the radar, and a photographing signal result of the radar image to implement the radar image; (S10) (b) the blue measurement server selecting one or more analysis regions on the radar image; (S20) (c) constructing a power spectrum of the selected analysis region through a fast Fourier transform; (S30) (d) determining an analysis region and calculating a direction wave spectrum for each analysis region; (S50) (e) synthesizing the direction wave spectrum for each analysis region; (S60) and (f) processing blue and algal information in the synthesized spectrum (S70); Blue measurement method using a radar, characterized in that comprises a. The method of claim 4, wherein after step (f), When the wave measurement system using the radar is applied to a moving ship, the method for measuring a wave using a radar, characterized in that further comprising the step of reconstructing the radar image using the ship's speed, azimuth information. The method of claim 4, wherein after step (f), Calculating a period, a wave direction, and the like for the significant wave height by averaging the wave heights from the direction wave spectrum to the ones corresponding to the third in the highest order of wave height generated during a certain time period. Blue measurement method used. The method of claim 4, wherein In step (d), (d-1) determining, by the blue measurement server, an analysis region (S51); (d-2) obtaining a 3D image spectrum by performing 3D fast Fourier transform (FFT) on the radar image data corresponding to the analysis region (S52); (d-3) performing, by the wave measurement server, filtering and tidal velocity estimation by applying dispersion relations according to ship speed, azimuth, and wave period and direction (S53); And (d-4) calculating, by the blue measurement server, the blue wave information using the direction wave spectrum by applying a correlation analysis result between the signal to noise ratio of the image spectrum and the actual blue wave (S55); Blue measurement method using a radar, characterized in that comprises a. The method of claim 7, wherein The algal velocity of step (d-3) is A method for measuring waves using a radar, characterized in that, as a result of a three-dimensional fast Fourier transform, a frequency value at which energy is distributed and an error value between the frequencies are minimum. The method of claim 4, wherein Radar signal of step (a), A method for measuring a blue wave using a radar, characterized in that at least one of a radar image signal, a trigger, a heading, and a bearing signal is included. The method of claim 7, wherein The determination of the analysis region of the step (d-1), How to determine one or two analysis areas according to wave direction and wave energy, how to determine an analysis area using statistical distribution, or how to determine the analysis area when there is a 90 degree difference in the same direction and wind direction. Blue measurement method using a radar, characterized in that one or more selected.

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