KR20170080416A - Sea surface wind measurement system and method using marine rader - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marine wind measurement system and a measurement method using a navigation radar.
The present invention provides a marine wind measurement system using a navigation radar, comprising: a radar for identifying an object within a certain range of a ship in operation and observing an obstacle in the sea, another ship, a coast, etc. and providing observed radar image data; And an azimuth measurement server for measuring the azimuthal wind by estimating the wind speed and the wind direction based on the radar image data provided from the radar image data.

Description

TECHNICAL FIELD [0001] The present invention relates to a marine wind measurement system and a measurement method using a navigation radar,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marine wind measurement system and method, and more particularly, to a marine wind measurement system using a marine radar capable of measuring the wind direction and wind speed of an off- And a measurement method.

Korea, located on the Korean peninsula, is highly influenced by the ocean climate due to its geographical characteristics. As a result, we are investing a lot of money and effort to apply it to real life and to utilize it in various industries by observing ocean weather. Here, the ocean meteorological observation refers to observations that perform the tide, wave, wave, wave, direction, flow velocity, wind direction, wind speed, etc., including weather elements at sea. In order to observe these, various instruments are installed at various places in the Meteorological Agency and the National Oceanographic Research Institute, and they are continuously observing and taking forecast data that can be used for life and industry based on the observed data.

As a representative method for observing ocean weather, there is a method of measuring by installing an observation sensor for observing the ocean gas phase. Observation sensors are installed in buoys for automatic observation of weather and sea conditions in the ocean. The value measured by the installed sensor is the most reliable at present.

However, much cost is incurred to install and maintain buoys and other equipment in the ocean to install the observation sensors. For example, Buoy's electronic module, which is installed with an observation sensor, is required to be waterproof. Therefore, it is necessary to inject nitrogen or freon gas to remove humid air in the module.

In addition, since the boats are installed in the ocean, they are always exposed to the risk of being damaged or lost by huge external forces such as collision with ships or typhoons.

As a result, there is a need for measuring equipment to replace or assist the buoy. In addition, marine vessels operating in waters free of landmarks are unable to directly use their measurement data, so they depend on the witnesses, but they are demanding objective measurement of marine weather in regulations such as IMO.

Korean Registered Patent No. 10-1351793 (January 9, 2014)

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a marine wind measurement system and a measurement method that can maintain accuracy while reducing maintenance cost by using a marine radar.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems to be solved by the present invention, which are not mentioned here, As will be appreciated by those skilled in the art.

The present invention relates to a marine wind measurement system using a marine radar, which is provided from radar and radar that observe an object within a certain range of a ship in operation and observe obstacles, other ships, And an ocean wind measurement server for measuring the wind direction by estimating the wind speed and the wind direction based on the radar image data.

The radar may be an X-band radar.

The azimuth measurement server includes a radar information collecting unit for receiving the radar image data from the radar and collecting information of the received image, a radar information collecting unit for separating the azimuths of the received radar image data by the same azimuth angle, And a wind speed estimating unit for estimating the wind speed using the reflection amount of the radar signal per unit area of the received radar image data through the radar information collecting unit and the wind direction estimating unit for estimating the wind direction by finding the largest value among the representative values of the radar image data.

The wind speed estimating unit may introduce a signal-to-noise ratio for estimating the wave height of the radar image data received through the radar information collecting unit to estimate the wind speed after establishing a relationship with the wind speed.

The method for measuring the sea air according to an embodiment of the present invention includes the steps of receiving radar image data observed in a marine radar, estimating a wind direction using radar image data, and estimating a wind speed using radar image data .

The step of estimating the wind direction includes the steps of separating radar image data by receiving azimuth angles, integrating radar image data separated by the same azimuth angle to define representative values, and estimating the direction of the largest value among the representative values as a wind direction . ≪ / RTI >

The step of estimating the wind speed may be any one of a first method of estimating the wind speed through the relationship between the wind speed and the wave height or a second method of estimating the wind speed through the relationship between the wind speed and the reflection amount of the radar signal per unit area Can be estimated.

The first method comprises the steps of: selecting an interpretation region in the radar image data; computing a 3D image spectrum of radar image data corresponding to the selected interpretation region; computing a signal-to-noise ratio through the 3D image spectrum; And estimating the wind speed using the wind speed.

The second method includes the steps of defining a unit area in the radar image data, defining a relationship between the radar signal reflection amount per unit area and the wind speed, and estimating the wind speed using the relationship between the radar signal reflection amount per unit area and the wind speed .

The marine wind measurement system and the measurement method according to the present invention can reduce the maintenance cost in the measurement process by measuring the sea wind using a low-cost X-band radar.

Further, in the marine wind measurement system and the measurement method according to the present invention, it is possible to estimate the wind velocity and the wind direction with the radar signal of the X-band radar and measure the sea wind having relatively high accuracy.

1 is a schematic view of a marine wind measurement system according to an embodiment of the present invention.
2 is a view showing a PPI image of a radar indicating a difference in reflectance of a radar signal according to a wind direction.
3 is a diagram showing a difference in reflectance of a radar signal according to a general wind direction.
4 is a diagram sequentially illustrating a method of estimating the wind direction using the marine wind measurement system according to an embodiment of the present invention.
5A and 5B are views illustrating an embodiment of estimating the wind direction through the marine wind measurement system according to an embodiment of the present invention.
FIG. 6 is a diagram sequentially illustrating a first method for estimating the wind speed through the sea-wind measurement system according to an embodiment of the present invention.
FIG. 7 is a view showing an example in which the wind speed estimated by the method of FIG. 6 and the actual measured value are compared.
FIG. 8 is a diagram sequentially illustrating a second method of estimating the wind speed through the marine wind measurement system according to an embodiment of the present invention.
9 is a diagram showing the relationship between the amount of reflection of the radar signal per unit area and the wind speed.
FIG. 10 is a view showing an example in which the wind speed estimated by the method of FIG. 8 is compared with the actual measured value.

The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the accompanying drawings.

2 is a view showing a PPI image of a radar showing a difference in reflectivity of a radar signal according to a wind direction, and Fig. 3 is a view showing a general wind direction And the reflectivity of the radar signal according to the present invention.

Referring to FIG. 1, the sea-based wind measurement system according to an embodiment of the present invention includes a radar 100 and a sea-level measurement server 200.

The radar 100 detects obstacles (marine structures), other ships, shores, and the like on a ship by checking an object within a certain range of the ship in operation, and detects a radar image signal, a trigger, a heading, ) Signal to provide a radar image. In more detail, the radar 100 is a radar device designed for use on a ship, which detects obstacles, other ships, coasts, etc. at sea and measures the distance and direction from the position and the self- Indicator.

The PPI image of the radar 100 indicates the time and direction taken for the signal irradiated from the radar antenna to collide with the sea surface and returns to the sea surface and the radar signal size for each azimuth at that time. The height and the size or direction of the sea- It does not show quantitative values, but it contains information about the period, height, and direction of the wave. Such a PPI image of the radar 100 may appear as shown in Fig. For reference, FIG. 2 shows a reflected signal according to a wind direction, and it can be seen that there is a dark region and a bright region according to the wind direction. Here, the bright region represents a large intensity of the radar signal. As described above, in one embodiment of the present invention, the wind direction and the wind speed can be measured using the reflected signal and the azimuth angle of the radar signal through the PPI image of the radar 100.

The PPI image of the radar 100 provides a wide range of spatial information unlike other measurement equipments, and time information can be obtained when a continuous image is obtained.

The radar 100 identifies objects within a certain range of the ship currently operating, and supports signal processing and display of the radar video.

The radar 100 in one embodiment of the present invention may be an X-band radar. Particularly, the radar 100 in the embodiment of the present invention is more suitable for the X-band radar because the sea surface measurement is required to grasp the physical characteristics of the wave. The X-band radar 100 may have an intermediate nature between the short and the long sides of each satellite. In addition, since the X-band radar 100 has less risk of loss than the unit, and the equipment itself is generally inexpensive, the X-band radar 100 can reduce the cost in the measurement process by measuring the sea air.

The marine wind measurement server 200 receives the radar signal from the radar 100, estimates the wind direction using the azimuth angle of the radar signal, and estimates the wind direction by using the radar signal. The sea surface measurement server 200 may include a radar information collecting unit 210, a wind direction estimating unit 220, a wind speed estimating unit 230, a display unit 240, and a control unit 250.

The radar information collecting unit 210 collects the information included in the PPI image after receiving the PPI image from the radar 100. In this case, the PPI image may include the time and direction taken to return to the sea surface, that is, the reflected signal, and the radar signal size by the azimuth at that time.

The wind direction estimating unit 220 estimates the wind direction using the intensity of the signal, that is, the azimuth, by the direction in which the radar signal is received from the PPI image collected through the radar information collecting unit 210. More specifically, the wind direction estimating unit 220 may divide the radar signal by the received azimuth angle, find the largest value among the representative values of the same azimuth angles, and estimate the wind direction. The reason for separating the radar signal by the azimuth angle is that generally, as shown in FIG. 3, since the intensity of the radar signal is high in the wind direction and the intensity of the radar signal is low in the opposite direction, The accuracy can be improved by estimating the wind direction. A method of estimating the wind direction of the wind direction estimating unit 220 will be described in detail with reference to FIG.

The wind speed estimating unit 230 can estimate the wind speed using the radar signal collected through the radar information collecting unit 210. [ In more detail, the wind speed estimating unit 230 estimates the wind speed through the relationship between the wind velocity and the wave height using the radar signal, or estimates the wind speed using the reflection amount of the radar signal per unit area. That is, the wind speed estimation unit 230 has a first method of estimating the wind speed through the relationship between the wind speed and the wave height, and a second method of estimating the wind speed using the reflection amount of the radar signal. In the first method, the signal-to-noise ratio (SNR) value is introduced to estimate the wave height, and the wind speed can be estimated by establishing the relationship with the wind speed. In the second method, the relationship between the normalized radar cross section (NRCS) per unit area and the wind speed can be established to estimate the wind speed. The method of estimating the wind speed of the wind speed estimating unit 230 will be described in detail below with reference to FIGS.

The display unit 240 displays the wind direction and the wind speed estimated through the wind direction estimating unit 220 and the wind speed estimating unit 230 so that the wind direction and the wind speed can be recognized from the outside.

The controller 250 controls operations of the radar information collecting unit 210, the wind direction estimating unit 220, the wind speed estimating unit 230, and the display unit 240.

Meanwhile, although not shown in the figure, the sea-level measurement server 200 may further include a storage unit. The storage unit may store a trigger, a heading, a bearing signal, and a video signal included in the radar image data, that is, the PPI image.

4 is a diagram sequentially illustrating a method of estimating the wind direction using the marine wind measurement system according to an embodiment of the present invention.

Referring to FIG. 4, in order to measure the wind direction, the radar signal received from the radar 100 is separated by the received azimuth angle (S410).

Then, the same azimuth components separated for each azimuth are integrated to define a representative azimuth (S420).

Then, the largest value among the representative values of the azimuth angles is found, and the direction of the largest value is estimated as the wind direction (S430). At this time, the largest value can be found as an approximate value through the following equation (1).

는 방위각 별 레이더 신호의 적분값,

는 레이더 신호 수신 방위각,

는 풍향을 나타낸다. 이때, 레이더(100)의 안테나가 수평 편파방식일 경우에 C는 0을 가질 수 있다. here,

Is an integral value of the radar signal per azimuth,

A radar signal receiving azimuth angle,

Indicates the wind direction. At this time, C may be 0 when the antenna of the radar 100 is a horizontal polarization type.

The wind direction can be measured by obtaining A, B, and C so that the value obtained through Equation 1 and the actual measured value through the radar 100 are minimized.

)은 최소 자승법을 이용하여 구할 수 있다.At this time, A, B, C, and wind direction

) Can be obtained using the least squares method.

5A and 5B are views illustrating an embodiment of estimating the wind direction through the marine wind measurement system according to an embodiment of the present invention.

As shown in FIG. 5A, the azimuth angle of the radar signal can be separated through the PPI image of the radar 100, and the integrated value of the radar signal is shown by the azimuth angle as shown in FIG. 5B. That is, referring to FIG. 5B, the representative value may be 120. FIG.

FIG. 6 is a diagram sequentially illustrating a first method for estimating the wind speed through the sea-wind measurement system according to an embodiment of the present invention.

Before referring to FIG. 6, the first method of estimating the wind speed is a method of estimating the wind speed by establishing the relationship with the wind speed by using the parameters related to the wave height without directly comparing the wind speed and the wave height. According to the Beaufort Scale, which indicates the state of the sea according to the wind speed, the wind speed is estimated through the relationship between the wind speed and the wave height because the wind speed and the wave height are proportional to each other .

Accordingly, the wind speed can be estimated using the signal-to-noise ratio (SNR) used for measuring the wave height.

Referring to FIG. 6, an arbitrary number of analysis regions are selected in the PPI image of the radar 100 (S610).

Thereafter, a 3D image spectrum is calculated using a three-dimensional FFT for transforming a part of the radar image selected as the analysis area into the frequency domain in the time domain (S620). The 3D image spectrum can be calculated through the following equation (2).

는 선속,

는 조류 등에 의한 해수면의 이동속도이다. 이때, 3차원 FFT는 입력된 PPI 영상으로부터 노이즈 외에 필요한 영상 데이터 값을 취득하기 위하여 소거시킬 노이즈 값을 고속으로 푸리에 변환을 수행하는 3차원 고속 푸리에 변환을 말한다. 또한, 3D 이미지 스펙트럼은 3차원 FFT를 통해 얻어진 영상 이미지의 스펙트럼을 말한다.Where g is gravitational acceleration, d is depth,

However,

Is the rate of sea level movement by algae and so on. In this case, the 3-dimensional FFT refers to a 3-dimensional fast Fourier transform that performs Fourier transform on a noise value to be erased in order to acquire image data values other than noise from an input PPI image. Also, the 3D image spectrum refers to the spectrum of the image obtained through the 3D FFT.

Then, a signal to noise ratio (SNR) is calculated through the 3D image spectrum (S630). At this time, the signal-to-noise ratio can be calculated by the following equation (3).

Then, the wind speed is estimated through the following equation (4) using the signal-to-noise ratio (S640).

Where U is the wind speed, A and B are constants that can be obtained by experiment and numerical analysis, and SNR is the signal-to-noise ratio.

FIG. 7 is a view showing an example in which the wind speed estimated by the method of FIG. 6 and the actual measured value are compared.

Referring to FIG. 7, it can be seen that the actual measurement value is similar to the wind speed value estimated by the first method. It can be seen that the similarity between the actual measured value and the wind speed value estimated by the first method is about 80%, which is high.

FIG. 8 is a diagram sequentially illustrating a second method of estimating the wind speed through the marine wind measurement system according to an embodiment of the present invention, and FIG. 9 is a diagram showing the relationship between the reflection amount of the radar signal per unit area and the wind speed.

8, the second method for estimating the wind speed is a technique for estimating the wind speed using the Normalized Radar Cross Section (NRCS) per unit area in the PPI image of the radar 100. In the second method of estimating the wind speed, the reason why the radar signal reflection amount per unit area is used is that the degree of coarsening of the sea surface varies depending on the wind speed and the reflectivity of the radar signal changes accordingly.

Referring to FIG. 8, a unit area is defined in the PPI image of the radar 100 (S810).

Then, the reflection amount (NRCS) of the radar signal per unit area is calculated, and the relationship between the wind speed and the radar signal reflection amount (NRCS) is defined as shown in Fig. 9 (S920). The wind speed and the radar signal reflection amount per unit area (NRCS) can be defined by the following equation (5).

,

는 실험과 수치해석으로 구할 수 있는 상수,

는 NRCS를 나타낸다. 또한, 상수

,

를 최소자승법으로 구한다.Where U is the wind speed,

,

Is a constant that can be obtained by experiment and numerical analysis,

Indicates an NRCS. Also,

,

By the least squares method.

Then, the wind speed is estimated using the relationship between the radar signal reflection amount per unit area and the wind speed (S930).

FIG. 10 is a view showing an example in which the wind speed estimated by the method of FIG. 8 is compared with the actual measured value.

Referring to FIG. 10, it can be seen that the actual measurement value is similar to the wind speed value estimated by the second method. The similarity between the actual measured value and the wind speed value estimated by the second method is about 83%, which indicates that the similarity is high.

As described above, since the radar itself is low in price and the risk of loss is low compared to the buoy by using the X-band radar according to the embodiment of the present invention, Can be reduced.

As described above, it is to be understood that the technical structure of the present invention can be embodied in other specific forms without departing from the spirit and essential characteristics of the present invention.

Therefore, it should be understood that the above-described embodiments are to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than the foregoing description, All changes or modifications that come within the scope of the present invention should be construed as being included within the scope of the present invention.

100: Radar
200: Oceanographic measurement server
210: Radar information collecting unit
220: Wind direction estimating unit
230: wind velocity estimation unit
240:
250:

Claims (9)

A radar which observes an object within a certain range of a ship in operation to observe obstacles at sea, other ships and coasts, and provides observed radar image data; And
And an ocean wind measurement server for measuring a sea wind by estimating a wind speed and a wind direction based on the radar image data provided from the radar. The method according to claim 1,
Wherein the radar is an X-band radar. The navigation system according to claim 1,
A radar information collecting unit for receiving the radar image data from the radar and collecting information of the received image;
A wind direction estimating unit that separates the azimuths of the radar image data received through the radar information collecting unit by the same azimuth angle and estimates the wind direction by finding the largest value among the representative values of the same azimuth angles; And
A wind speed estimating unit for estimating a wind speed using a reflection amount of the radar signal per unit area of the radar image data received through the radar information collecting unit;
And an airflow meter. The wind speed estimating apparatus according to claim 3,
And a signal-to-noise ratio for estimating the wave height of the radar image data received through the radar information collecting unit is introduced to establish the relationship with the wind speed, and then the wind speed is estimated. Receiving radar image data observed in a marine radar;
Estimating a wind direction using the radar image data; And
And estimating a wind speed using the radar image data. 6. The method of claim 5, wherein estimating the wind direction comprises:
Separating the radar image data by a received azimuth angle;
Integrating the radar image data separated by the same azimuth angle to define a representative value; And
And estimating a direction of a largest value among the representative values as a wind direction. 6. The method of claim 5, wherein the estimating the wind speed comprises:
A first method of estimating the wind speed through the relationship between the wind speed and the wave height or a second method of estimating the wind speed through the relationship between the wind speed and the reflection amount of the radar signal per unit area, . 8. The method according to claim 7,
Selecting an analysis region from the radar image data;
Calculating a 3D image spectrum of radar image data corresponding to the selected analysis region;
Computing a signal-to-noise ratio through the 3D image spectrum; And
And estimating the wind speed using the signal-to-noise ratio. 8. The method according to claim 7,
Defining a unit area in the radar image data;
Defining a relationship between the reflection amount of the radar signal per unit area and the wind speed; And
And estimating the wind velocity using the relationship between the reflection amount of the radar signal per unit area and the wind speed.

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