KR20120040025A - System and method for estimating rainfall using a ship radar - Google Patents

Abstract

PURPOSE: A system for estimating localized rainfall based on a vessel radar and an estimating method of the same are provided to scan and observe regions based on a plan position indicator(PPI) method. CONSTITUTION: A system for estimating localized rainfall based on a vessel radar includes a vessel radar(100), a fence, an analog to digital(AD) converter, and a localized rainfall estimating server(300). The vessel radar scans and observes a target area based on a PPI method. The fence is installed around the vessel radar and reflects downward beam generated from the vessel radar and eliminates clutter from the beam. The AD converter converts signals from the vessel radar and generates radar reflection signals. The radar reflection signals are transmitted from the AD converter to the localized rainfall estimating server. The localized rainfall estimating server reflects transmitted radar reflection signals to rainfall information generating algorithm generates the rainfall information of the target area.

Description

System for estimating local precipitation using ship radar and its estimation method {SYSTEM AND METHOD FOR ESTIMATING RAINFALL USING A SHIP RADAR}

The present invention relates to a method of estimating local precipitation using a ship radar, and more particularly, reflecting a reflectance value of a ship radar scanning an area of interest to a preset rainfall information generation algorithm to calculate precipitation in a region of interest in real time. The present invention relates to a system for estimating local precipitation using a ship radar capable of effectively estimating local precipitation and a method of estimating the local precipitation.

The present invention relates to a system for estimating local precipitation using a ship radar and an estimation method thereof.

Radar is a remote observation device that tracks the position and intensity of a target by analyzing the signal reflected from the target by radiating electromagnetic waves toward the target. It is possible to measure.

The weather radar defines a magnitude of a signal reflected from a weather target such as rain or snow as a reflectance and uses a method of estimating precipitation from the reflectance.

The reflectivity from the target is related to the size distribution of the droplets within the pulse volume emitted by the weather radar.

And since the rainfall on the ground is a function of the size distribution of the droplets, the ZR relation between the radar reflectivity and the precipitation (z = AR ^b , where R is Rainrate (mm / h), and z is the reflectance (mm ⁶ , m ³ ) , A and b are experience). Therefore, the precipitation can be estimated from the radar reflectivity.

In general, the scanning of the weather radar has a fixed altitude angle fixedly and the antenna is rotated for observation (PPI: Plan Position Indicator) and the volume observation repeatedly observed while changing the antenna elevation angle.

On the other hand, volume observation is generally performed for meteorological observation.

Traditional weather radar rotates 360 degrees at a certain altitude, and then repeats the cycle of 360 degrees with an elevation of 1 degree. The entire turn to 24 elevations usually takes 5 to 15 minutes. do.

This means that it takes a long time to scan the same point again after scanning for a specific point, and the problem of losing the meaning as observation data already takes into account considering that the weather target frequently changes its position due to the wind. have.

In addition, since the horizontal resolution is only a maximum of 1 km x 1 km, there is a problem in that it is difficult to analyze local weather and predict short-term weather changes.

In addition, the traditional weather radar is difficult to observe due to the earth curvature of the altitude close to the earth surface, there is a problem that the weather phenomenon located 1.5 to 3km above the ground, such as snow or tornado is not detected.

These problems have resulted in inadequate reliability in rainfall estimation and short-term forecasting using radar, and there is a problem in that it is not possible to effectively cope when an instrument such as local heavy rain occurs.

The present invention has been invented to solve the above problems, and the present invention is conventionally performed by scanning a relatively small observation area using a PPI (PPI: Plan Position Indicator) method using an X-band type ship radar with high horizontal resolution. A system for estimating local precipitation using a ship radar capable of effectively estimating local precipitation by overcoming the problems caused by weather radar and using the ship radar for meteorological observations. It aims to provide the estimation method.

In addition, the present invention by reflecting the reflectance value of the ship radar for scanning the region of interest to a predetermined rainfall information generation algorithm to calculate the precipitation of the region of interest in real time by using the vessel radar that can effectively estimate the local precipitation An object of the present invention is to provide a system for estimating precipitation and a method of estimating the precipitation.

In order to achieve the above object, a system for estimating local precipitation using a ship radar according to the present invention includes a ship radar for scanning and observing a region of interest by a PPI (Plan Position Indicator) method; A fence installed around the ship radar and reflecting a downward beam generated by the ship radar to remove clutter; An AD converter which receives a predetermined signal from the ship radar and converts the AD to generate a radar reflectivity signal; And a local precipitation estimation server that receives the radar reflectivity signal from the AD converter and generates and provides precipitation information of the region of interest by reflecting the radar reflectivity signal to a preset rainfall information generation algorithm.

At this time, the local precipitation estimation server, the radar reflectivity signal receiving unit for receiving a radar reflectivity signal from the AD converter; A precipitation information generator for generating local precipitation information by reflecting the radar reflectivity signal to a preset rainfall information generation algorithm; A GPS information receiver for receiving GPS information of the region of interest from the GPS; A GIS information receiver configured to receive GIS information of a region of interest from the GIS; And a screen output information generation unit configured to generate a screen output information after processing the linking information of the GPS of interest area, GIS information, and precipitation information when receiving a request to receive precipitation information of a region of interest from the user terminal. It includes.

The local precipitation estimation server may further include a storage unit in which a rainfall information generation algorithm is stored.

When the local precipitation estimation server receives a request to access the local precipitation estimation server from a user terminal, the local precipitation estimation server performs an authentication procedure and when the user who has obtained the authentication inputs a request to receive precipitation information of a predetermined region of interest. The processor may further include a central processor configured to process precipitation information of the region of interest to be provided in real time.

On the other hand, when the central processing unit receives a remote control request signal of the local precipitation estimation server from the user terminal that has been authenticated, it is preferable to process the user terminal so as to remotely control the local precipitation estimation server.

And the fence, the reflecting surface for reflecting the electromagnetic wave irradiated by the ship radar; And a fence support for supporting the reflective surface.

In this case, the height of the fence support coincides with the beam centerline scanned by the ship radar, the size of the reflecting surface corresponds to the physical size of the downward beam directed below the beam centerline, the horizontal angle of the reflecting surface is the angle of the downward beam It is desirable to be smaller than the angle of excitation.

In order to achieve the above object, a method of estimating local precipitation using a ship radar according to the present invention is to irradiate a ship radar to a region of interest, but reflects a downward beam directed below a beam centerline by using a fence to clutter. (A) removing the; (B) generating an radar reflectivity signal by AD converting the AD converter after receiving a predetermined signal from the ship radar; (C) generating, by the local precipitation estimation server, precipitation information of the region of interest by reflecting the radar reflectivity signal converted in step (B) to a preset rainfall information generation algorithm; And the local precipitation estimation server processes the precipitation information generated by the step (C) in association with the GIS information and the GPS information of the region of interest, generates screen output information, and requests the precipitation information of the region of interest. (D) providing to the terminal; includes.

(E) if the local precipitation estimation server receives a request to access the local precipitation estimation server from a user terminal, performing an authentication procedure; And (F) if the user terminal obtains the authentication in step (E), processing the local precipitation estimating server to control the local precipitation estimating server remotely. .

According to the present invention, the present invention has an advantage of effectively estimating local precipitation by reflecting a reflectance value of a ship radar scanning an area of interest to a preset rainfall information generation algorithm to calculate the precipitation of the area of interest in real time. .

In addition, the present invention can overcome the problems of the traditional weather radar by scanning a relatively small observation area by using the PPI (PPI: Plan Position Indicator) method using the X-band vessel radar of high horizontal resolution There is this.

In addition, the present invention can solve the problem caused by using the ship radar for weather observation technically to calculate the local precipitation effectively, there is an advantage to provide convenience to the administrator by easy transport and installation.

1 is a system diagram showing the overall configuration of a system for estimating local precipitation using a ship radar according to a preferred embodiment of the present invention.
2 and 3 are explanatory diagrams showing that a ship radar of the present invention performs a PPI (Plan Position Indicator) scan.
4 and 5 are explanatory diagrams for explaining the fence of the present invention.
6 is a block diagram showing the internal configuration of the local precipitation estimation server of FIG.
7 is an explanatory diagram for explaining the precipitation information generation algorithm of the present invention;

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of a system for estimating local precipitation using the ship radar according to the present invention as described above will be described in detail.

1 is a system diagram showing the overall configuration of a system for estimating local precipitation using a ship radar according to a preferred embodiment of the present invention.

As shown in FIG. 1, the present invention provides a ship radar 100, a fence (not shown), an AD converter 200, a local precipitation estimation server 300, a GPS 400, a GIS 500, and a user terminal 600. ).

The ship radar 100 scans and observes a region of interest by a plan position indicator (PPI) method. The ship radar 100 includes a transmitter, an antenna, a receiver, and a display. The transmitter generates a high frequency signal, the antenna shoots the signal into space to receive echoes reflected from the target, and the receiver amplifies the received signal to a size sufficient to detect and utilize it. The display unit is a monitor made exclusively for use and generally includes a radar control unit internally. Ship radar 100 as described above has an excellent horizontal resolution and has the advantage of effective in analyzing weather phenomena close to the earth's surface.

The vessel radar 100 may scan the space where the target is located with one PPI SCAN as shown in FIG. 2 with a beam width of 20 degrees in the vertical direction and 0.95 degrees or 3.9 degrees in the horizontal direction. 2 and 3 are explanatory views showing that the ship radar 100 performs a Plan Position Indicator (PPI) scan.

Meanwhile, since the ship radar 100 is originally intended to catch a marine target even in a situation in which the ship rolls back, forth, left, and right, the vertical beam transmission form is shown as shown in FIG. It will be sent back. Therefore, if the beam center line is positioned parallel to the horizontal line, the downward beam is directed to the ground surface.

When the ship radar 100 is installed and operated on the ground for observation on the ground, the downward beam directed toward the ground makes a clutter signal irrelevant to the target weather phenomenon, which is inconsistent with the target. Results.

Therefore, the present invention includes a fence for removing the clutter signal by reflecting the downward beam in order to overcome the problems described above.

That is, the fence is installed around the ship radar 100 to reflect the downward beam generated by the ship radar 100 to remove clutter.

4 and 5 are explanatory views illustrating the fence of the present invention.

As shown in these figures, the fence includes a reflecting surface for reflecting electromagnetic waves emitted by the ship radar and a fence support for supporting the reflecting surface.

In this case, the height of the fence support coincides with the beam centerline scanned by the ship radar, the size of the reflecting surface corresponds to the physical size of the downward beam directed below the beam centerline, the horizontal angle of the reflecting surface is the angle of the downward beam It is desirable to be smaller than the angle of excitation.

As shown in FIG. 4, the height of the fence support is equal to the beam center line, and the horizontal angle a of the reflective surface is smaller than the opening angle of the downward beam angle while the reflective surface size of the fence is adjusted to match the physical size of the downward beam. In this case, only the downward beam of the ship radar can be reflected and removed.

Meanwhile, the downward beam of the ship radar toward the reflective surface of the fence is basically reflected by the SNELL'S LAW in a direction unrelated to the radar antenna.

The AD converter 200 receives a predetermined signal from the ship radar 100, and then converts AD to generate a radar reflectivity signal. Since the reflectance signal in the ship radar is represented as an RGB video signal according to its intensity, in the present invention, the video signal output from the viewer of the ship radar is periodically captured using the AD converter 200 to the BMP IMAGE FILE. Convert and save.

On the other hand, in the present invention, the video signal output from the display (viewer) is a reflectance signal expressed in RGB, it is necessary to scan only the MONOCHROME COLOR in order to distinguish the phase of the reflectance, in the present invention, the radar is so that the RGB output is made of MONO Control and SCAN the value to convert to PIXEL separated by 256 LEVEL.

The specification of the AD converter 200 is designed in consideration of the input and output signal characteristics of the ship radar 100, the RGB color resolution can support up to RGB24, RGB16, RGB8, YUY2, UYUV, PIXEL Rate can be up to 250 MPixel / s It is preferable.

Since the antenna rotation speed of the ship radar 100 is up to 24 RPM, the video can be SCAN from the maximum 24 FPS. In the present invention, the AD converter 200 may adjust the SCAN RATE from 24 to once per minute, and the result is transmitted to the local precipitation estimation server 300 and the local precipitation estimation server 300 specifies a user-specified FILE NAME. It saves in the form designated by user such as BMP FILE according to.

The local precipitation estimation server 300 receives the radar reflectivity signal from the AD converter 200 and generates and provides precipitation information of the region of interest by reflecting the radar reflectivity signal in a preset rainfall information generation algorithm. The local precipitation estimation server 300 will be described in more detail with reference to the drawings below.

The GPS 400 provides local GPS information to the local precipitation estimation server 300.

The GIS 500 provides local GIS information to the local precipitation estimation server 300.

FIG. 6 is a block diagram showing the internal configuration of the local precipitation estimation server of FIG.

The local precipitation estimation server 300 includes a radar reflectivity signal receiver 310, a precipitation information generator 320, a GPS information receiver 330, a GIS information receiver 340, a screen output information generator 350, a central processor ( 360, the storage unit 370.

The radar reflectivity signal receiver 310 receives the radar reflectivity signal from the AD converter 200.

The precipitation information generation unit 320 generates local precipitation information by reflecting the radar reflectivity signal to a preset rainfall information generation algorithm.

Hereinafter, the rainfall information generation algorithm will be described in detail.

It is possible to adjust the SCAN area of the AD converter 200 by a pre-specified precipitation function in FIG. 7. In FIG. 7, the left side shows the original AD converter 200 driving area, and the center part shows the ratio of the AD signal while the AD converting the reflectance signal. It is a schematic diagram of the step-by-step transformation from LEVEL_1 where there is no signal reflected at all and from LEVEL_256, which represents the strongest reflectivity due to heavy rain.

As shown in FIG. 7, the reflectance signal appearing according to the degree of precipitation may tend to be distributed in a specific level section according to regional and seasonal characteristics rather than evenly distributed step by step from LEVEL_1 to LEVEL_256.

Therefore, in the present invention, in order to classify the precipitation, the user can designate a precipitation function, so that when the entire SCAN area is viewed as 1 by the specified precipitation function, the whole area is converted as it is 1. If you want to enlarge the SCAN area by 2 times, it is possible to enlarge the area from LEVEL_1 to LEVEL_128 when the precipitation function is 1, as shown in the figure on the right.

By using the precipitation function, it is possible to accurately classify the degree of falling even if the precipitation does not fall much according to regional and seasonal characteristics. The precipitation function has an initial value of 1 and is designed to be adjusted from 1 to 5.

Equation 1 is a radar equation for a weather target that fills a radar beam.

는 각각 레이더의 수평과 수직 빔 폭이고, r은 레이더와 샘플 볼륨까지 거리이며, h는 펄스 길이, g는 레이더 안테나 이득,

는 레이더의 전자기파 파장, P_r 은 레이더 수신부로부터 측정되어 나오는 전력값, Pt는 레이더가 방사한 전력값을 말한다. L은 모든 감쇄에 기인한 전손실(total loss)을 설명할 수 있는 항목이며, K는 매질의 반사와 관련된 복소 함수이다.here,

Are the horizontal and vertical beam widths of the radar, r is the distance to the radar and the sample volume, h is the pulse length, g is the radar antenna gain,

Is the radar electromagnetic wave wavelength, P _r is the power value measured from the radar receiver, and Pt is the power value emitted by the radar. L is an item that can explain total loss due to all attenuation, and K is a complex function related to the reflection of the medium.

다. 더 나아가서 숫자들(

)도 묶을 수 있다. Radar equations can be made fairly simple for a radar that works properly. This is because variables related to a particular radar can be grouped together and treated as a constant. The variables included here are P _t , g,

All. Going further, numbers

) Can also be tied.

Then, Equation 1 may be expressed as Equation 2.

값은 0.93이다.Here, k value is a value which changes according to a substance, temperature, and radar wavelength. Temperature and wavelength do not affect much, but they need to be considered to be accurate, and the type of material must be considered. When using radar, if the temperature is under reasonable conditions,

The value is 0.93.

Then, if we are primarily interested in atmospheric waters of water rather than ice, then the K value is 1, which leads to Equation 3.

Here, C ₂ is different from C ₁ above. Equation 3 is the equation for a weather target filled with a radar beam. According to this equation, the received power is proportional to the radar reflection factor of the storm and inversely proportional to the square of the distance. The stronger the storm, the stronger the reflection and the greater the power received. Distance changes are also important.

The core of the present invention is for the radar reflectivity z, so rearranging based on z yields Equation 4.

The constant C ₃ in [Equation 4] is the radar constant (RADAR CONSTANT in mm ⁶ / m ³ mW ^-1 km ^-2 ). In the following, the radar reflectivity z is briefly examined. Here, reflectivity is a meteorological parameter that is determined by the size and number of particles in the sample volume.

It's easier to see a narrower number than z's huge range. This is done by making the original linear function logarithmic. Therefore, the radar reflectivity Z can be defined as shown in [Equation 5].

Z is a known property for Rayleigh scattering conditions (when the radar reflection cross section is smaller than the wavelength).

or

Where D: precipitation diameter [mm] and N (D) refer to the concentration number or size distribution [m-3] of the falling particles per unit volume.

In the Marshall-Palmer relation, the size distribution represents the distribution of inverse exponential function while providing the size distribution characteristic for raindrop as a function of rainrate.

Where N ₀ = 8000 / (m ³ mm), D is the diameter of the droplet (mm), and lambda is calculated by Equation (8), and R is the rainfall rate-Rainrate (mm / h).

The inverse exponential distribution is shown graphically in [Table 1].

On the other hand, when [Equation 6] is substituted into [Equation 7], [Equation 9] is generated.

인 감마 함수이다.On the other hand, if a well-known general solution for infinite integration in the integral table is found and applied, it is represented by Equation 10. here,

Is a gamma function.

Substituting [Equation 9] and [Equation 10], it becomes [Equation 11].

Therefore, if N ₀ and lambda are known, Z can be obtained from Equation (11). N ₀ and lambda can be determined by measuring with a drdrometer or ZD-P.

For example, if MP48 and [Equation 7], R = 25.4mm / h,

From Equation 11

Taking the logarithm of the above values gives Z = 45.3 dBZ.

So far, if the radar reflectivity Z has been calculated from the rainfall rate, it is possible to estimate the rain rate from the reflectivity.

Rainfall is the flux of matter, such as the amount of rain falling on the surface, expressed in FR, and defined as the flow of rain that falls on a unit area per unit time (unit is kg / m ² s).

Given N (D), the rainfall rate-Rainrate is defined and calculated as shown in [Equation 12].

Where m (D) is the mass of the substance as rain, kg, N (D) is 1 / m ³ mm in size distribution, and V (D) is m / s at the falling velocity.

Substituting this in [Equation 12],

[수학식 8]

&Quot; (8) "

Equation 10 In the gamma function

Rain rate [R], however, is usually expressed as the depth of rain (mm / h). To find [R], divide Rainrate F _R obtained above by density, change time units, and change depth to mm.

[unit]

The a, b from the rate of fall of the rain, V (D), is expressed in terms of empirical equations by Atlas and Ulbrich in 1977.

If we develop the Z-R relation by combining Equations 11 and 15, we can estimate R from the radar reflectivity Z measurements as shown in Equation 17.

Then, the Z-R relation can be expressed as [Equation 18] in the power law form.

In the present invention, the above-described equations are processed by the rainfall information generation algorithm to obtain rainfall rate-RAINRATE, that is, precipitation information from the reflectance signal.

The GPS information receiver 330 receives the GPS information of the ROI from the GPS 400.

The GIS information receiver 340 receives the GIS information of the region of interest from the GIS 500.

When the screen output information generation unit 350 receives a request for receiving precipitation information of a region of interest from the user terminal, the screen output information generation unit 350 processes and processes the screen output information after linking the GPS information, the GIS information, and the precipitation information of the region of interest. Create

Precipitation information can determine the latitude and longitude data when initializing the observation area in the radar, so that each pixel on the horizontal coordinate can also be included in calculating the latitude and longitude. Each PIXEL grid has its own latitude, longitude, and precipitation information. The screen output information generation unit 350 connects GIS and GPS to the PIXEL grid so as to provide precipitation information to the user like specific geographic information.

When the central processing unit 360 receives a request for accessing the local precipitation estimation server from the user terminal 600, the central processing unit 360 performs an authentication procedure and inputs a request for the user who obtained the authentication to receive precipitation information of a predetermined region of interest. If so, the precipitation information of the region of interest is provided in real time.

In addition, when the central processing unit 360 receives a remote control request signal of the local precipitation estimation server from the user terminal 600 that has obtained the authentication, the user terminal 600 may remotely control the local precipitation estimation server. Process. That is, the user can perform operations such as selecting and moving the region of interest, changing the precipitation function, controlling the local radar system, and remotely transmitting the rainfall rate information through the Internet connection.

The storage unit 370 stores a rainfall information generation algorithm.

The present invention has been shown and described with respect to specific preferred embodiments thereof. However, the present invention is not limited to the above-described embodiments, and various changes and modifications may be made without departing from the technical spirit of the present invention by those skilled in the art. Accordingly, the scope of the present invention should be construed as being determined not by the specific embodiments but by the appended claims.

100: ship radar 200: AD converter
300: local precipitation estimation server 310: radar reflectivity signal receiver
320: precipitation information generating unit 330: GPS information receiving unit
340: GIS information receiver 350: Screen output information generator
360: central processing unit 370: storage unit
400: GPS 500: GIS
600: user terminal

Claims (9)

A ship radar that scans and observes a region of interest using a Plan Position Indicator (PPI) method;
A fence installed around the ship radar and reflecting a downward beam generated by the ship radar to remove clutter;
An AD converter which receives a predetermined signal from the ship radar and converts the AD to generate a radar reflectivity signal; And
A local rainfall estimation server that receives the radar reflectivity signal from the AD converter and generates and provides precipitation information of the region of interest by reflecting the radar reflectivity signal to a preset rainfall information generation algorithm. A system for estimating local precipitation using.
The method of claim 1, wherein the local precipitation estimation server,
A radar reflectivity signal receiver configured to receive a radar reflectivity signal from an AD converter;
A precipitation information generator for generating local precipitation information by reflecting the radar reflectivity signal to a preset rainfall information generation algorithm;
A GPS information receiver for receiving GPS information of the region of interest from the GPS;
A GIS information receiver configured to receive GIS information of a region of interest from the GIS; And
A screen output information generator configured to generate a screen output information after processing the link information of the ROI by receiving GPS information, GIS information, and precipitation information; And a system for estimating local precipitation using a ship radar.
The method of claim 2, wherein the local precipitation estimation server,
And a storage unit for storing rainfall information generation algorithms.
The method of claim 3, wherein the local precipitation estimation server,
When the user terminal receives a request to access the local precipitation estimation server, the authentication process is performed, and when the user who has obtained the authentication inputs a request to receive precipitation information of a predetermined region of interest, precipitation information of the region of interest is displayed. A central processing unit for processing to be provided in real time; System for estimating local precipitation using a ship radar, characterized in that it further comprises.
The method of claim 4, wherein the central processing unit,
When the remote control request signal of the local precipitation estimation server is received from the user terminal that has been authenticated, the local precipitation is estimated by using the ship radar, which is processed so that the user terminal can remotely control the local precipitation estimation server. System.
The method of claim 1, wherein the fence,
A reflection surface reflecting electromagnetic waves irradiated by the ship radar; And
And a fence support for supporting the reflective surface.
The method of claim 6,
The height of the fence support coincides with the beam centerline scanned by the ship radar, and the size of the reflecting surface corresponds to the physical size of the downward beam directed below the beam centerline, and the horizontal angle of the reflecting surface is the angle of the downward beam angle. A system for estimating local precipitation using a ship radar, characterized in that it is smaller than the head angle.
Irradiating the ship radar to the region of interest but removing a clutter by reflecting a downward beam pointing below the beam centerline using a fence;
(B) generating an radar reflectivity signal by AD converting the AD converter after receiving a predetermined signal from the ship radar;
(C) generating, by the local precipitation estimation server, precipitation information of the region of interest by reflecting the radar reflectivity signal converted in step (B) to a preset rainfall information generation algorithm; And
The local precipitation estimation server processes the precipitation information generated in step (C) in association with the GIS information and the GPS information of the region of interest, generates screen output information, and requests the precipitation information of the region of interest. (D) providing to; a method for estimating local precipitation using a ship radar comprising a.
The method of claim 8,
(E) if the local precipitation estimation server receives a request for accessing the local precipitation estimation server from a user terminal, performing an authentication procedure; And
(F) if the user terminal obtains the authentication by the step (E), processing the local precipitation estimation server to allow the user terminal to control the local precipitation estimation server remotely. Method of estimating local precipitation using ship radar.

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