KR20230006193A - Device for attenuation correction of x-band dual polar radar reflectivity using adjacent multiple terrestrial microwave links and method therefor - Google Patents

Abstract

The present invention relates to an apparatus and a method for correcting X-band dual-polarization radar reflectivity and, more specifically, to an apparatus and a method for correcting X-band dual-polarization radar reflectivity by using multi-ground communication base station microwaves. In accordance with the present invention, the apparatus and the method for correcting X-band dual-polarization radar reflectivity by using multi-ground communication base station microwaves, can determine an optimal attenuation correction coefficient considering a space-time change of rainfall. Moreover, in accordance with the present invention, the apparatus and the method for correcting X-band dual-polarization radar reflectivity by using multi-ground communication base station microwaves can have an advantage of stably calculating an attenuation correction coefficient even when a specific microwave link cannot provide attenuation data due to a mechanical cause The apparatus includes an observation data collection module, a microwave attenuation calculation module, a rainfall detection module and a reflectivity correction module.

Description

X-band dual polarization radar reflectivity correction device and method using multi-terrestrial communication base station microwaves

The present invention relates to an X-band dual polarization radar reflectivity correction device and method, and more particularly, to an X-band dual polarization radar reflectivity correction device and method using microwaves of multiple terrestrial communication base stations.

) 변수를 활용하여 레이더 감쇠 보정 계수

를 산출하여 엑스밴드 레이더 감쇠 보정을 할 수 있는 방법이 개발되었다. 본 발명에서는 차등위상차 변수와 방송·통신·데이터 중계용으로 사용되고 있는 지상 통신 기지국(이하, 지상 마이크로파 링크) 마이크로파 감쇠 자료를 기준 값으로 이용하여 시공간적으로 변동하는 강수를 고려할 수 있는 레이더 감쇠 보정 계수

를 산출하여 감쇠가 발생한 엑스밴드 이중 편파 레이더의 반사도를 보정할 수 있는 방법을 새롭게 제안한다.Weather radar (Radio Detection And Ranging, RADAR) is a remote observation device that transmits electromagnetic waves, hits a target (precipitation particles), receives back-scattered electromagnetic waves, and measures the intensity and distance of precipitation particles. X-band radar, which has a relatively short wavelength compared to S-band and C-band radar, has good resolution and can be operated with a small-sized antenna, which can reduce rainfall observation costs and is mounted on vehicles. It has the advantage of being able to perform observations in the blind area of rainfall observation. Large radars such as S-Band and C-Band are mostly built near mountain peaks, so there are limitations in beam shielding and radar elevation angle to measure rainfall in downtown areas and low-rise areas. Since the beginning of the CASA (Collaborative Adaptive Sensing of the Atmosphere) program in the United States and Japan, X-band radar networks have been established in areas where rainfall observation is not available, and efforts have been made to overcome the limitations of S-band and C-band radar in rainfall observation. However, X-band radar reflectivity with a short wavelength (3 cm) is greatly attenuated by the strong precipitation echo, so it is impossible to detect the precipitation echo to the rear of the azimuth angle of the corresponding precipitation, so the size of the reflectivity must be corrected. Since the introduction of x-band dual polarization radar, differential propagation phase

) radar attenuation correction factor using the variable

A method for calculating X-band radar attenuation correction has been developed. In the present invention, a radar attenuation correction coefficient capable of considering temporally and spatially varying precipitation by using differential phase difference variables and microwave attenuation data of a terrestrial communication base station (hereinafter, terrestrial microwave link) used for broadcasting, communication, and data relaying as reference values.

We propose a new method for correcting the reflectivity of the X-band dual polarization radar in which attenuation has occurred by calculating .

Republic of Korea Patent Registration No. 10-1291980 (registered on July 25, 2013)

An object of the present invention is to provide a correction device and method for correcting dual polarization X-band radar reflectivity of which radio wave attenuation due to precipitation is large.

The object of the present invention is not limited to the above-mentioned object, and other objects and advantages of the present invention not mentioned above can be understood by the following description and will be more clearly understood by the examples of the present invention. It will also be readily apparent that the objects and advantages of the present invention may be realized by means of the instrumentalities and combinations indicated in the claims.

)와, 엑스밴드 레이더의 레이더 반사도(

)를 이용하여 산출된 감쇠 보정된 레이더 반사도(

)로 엑스밴드 레이더 반사도를 보정하는 엑스밴드 레이더 반사도 보정 모듈을 가지는 반사도 보정 모듈을 포함한다.An X-band dual polarization radar reflectivity correction device using microwaves of a multi-terrestrial communication base station according to the present invention collects transmission power and reception power of a microwave link, and at least one or more automatic weather observation equipment installed around the microwave link ( Using the rain detector of the Automatic Weather System (AWS) and the observation data collection module that collects the cumulative rainfall data and rainfall time data recorded at regular intervals in the rain gauge, and the difference between the transmit power and receive power of the microwave link, A microwave attenuation calculation module that calculates microwave attenuation, a rain presence detection module that detects whether or not there is rain based on the autocorrelation coefficient of microwave attenuation, and attenuation size for each X-band radar gate (r) when the rain presence detection module detects rain (

) and the radar reflectivity of the X-band radar (

) attenuation-corrected radar reflectivity calculated using

) and a reflectivity correction module having an X-band radar reflectivity correction module for correcting the X-band radar reflectivity.

와 감쇠 보정 계수

, b를 적용하여 계산한 게이트(r)별 엑스밴드 레이더 감쇠 크기

로 감쇠 보정한 레이더 반사도

를 산출하여 엑스밴드 레이더 반사도를 보정하는 단계를 포함한다.In addition, in the X-band dual polarization radar reflectivity correction method using multi-terrestrial communication base station microwaves according to the present invention, the observation data collection module collects the transmission power and reception power of the microwave link, and at least one installed around the microwave link Between the step of collecting the cumulative rainfall data and rainfall time data recorded at regular intervals in the rain detector and rain gauge of the Automatic Weather System (AWS) of the Korea Meteorological Administration and the transmission power and reception power of the microwave link Using the difference, the microwave attenuation calculation module calculates the microwave attenuation, the rain presence detection module detects whether or not there is rain based on the autocorrelation coefficient of the microwave attenuation, and the reflectance correction module determines the cost function and the attenuation correction coefficient Calculate , radar reflectivity and reflectivity

and the attenuation correction factor

X-band radar attenuation for each gate (r) calculated by applying , b

Attenuation-corrected radar reflectivity with

and correcting the X-band radar reflectivity by calculating .

)는,

이며,

은 엑스밴드 레이더 감쇠 크기로서,

이고,

,

,

, b는 엑스밴드 레이더의 감쇠 보정 계수이다.Here, the attenuation corrected radar reflectivity (

)Is,

is,

is the magnitude of the X-band radar attenuation,

ego,

,

,

, b is the attenuation correction coefficient of the X-band radar.

An apparatus and method for correcting X-band dual polarization radar reflectivity using microwaves of a multi-terrestrial communication base station according to the present invention can determine an optimal attenuation correction coefficient that can consider temporal and spatial variations in rainfall.

In addition, the X-band dual polarization radar reflectivity correction device and method using multi-terrestrial communication base station microwaves according to the present invention can stably calculate the attenuation correction coefficient even when a specific microwave link cannot provide attenuation data due to mechanical reasons. There are advantages to being

In addition to the effects described above, specific effects of the present invention will be described together while explaining specific details for carrying out the present invention.

와 b를 수학식 6에 적용하여 산출한 엑스밴드 레이더 감쇠장을 나타낸 것이다.
도 5는 산출한 엑스밴드 레이더 게이트 별 감쇠 크기

를 수학식 10에 적용하여 감쇠 보정한 엑스밴드 레이더 반사도를 나타낸 것이다.
도 6은 기상청이 서울시에서 운영중인 AWS 위치에서의 감쇠 보정 전의 엑스밴드 레이더 반사도와 에스밴드 레이더 반사도 간의 산포도를 나타낸 것이다.
도 7은 감쇠 보정한 엑스밴드 레이더 반사도와 에스밴드 레이더 반사도 간의 산포도를 나타낸 것이다.
도 8은 층상운 사례인 2016년 5월 2일 22시의 한국건설기술연구원의 감쇠 보정 전의 엑스밴드 레이더 반사도(PPI)를 나타낸 것이다.
도 9는 기상청의 에스밴드 레이더 반사도(PPI)를 나타낸 것이다.
도 10은 7개의 마이크로파 링크 감쇠를 수학식 1에서 수학식 9까지 적용하여 산출한 최적의 감쇠 보정 계수를 수학식 6에 적용하여 산출한 엑스밴드 레이더 감쇠장을 나타낸 것이다.
도 11은 산출한 엑스밴드 레이더 게이트 별 감쇠 크기

를 수학식 10에 적용하여 감쇠 보정한 엑스밴드 레이더 반사도를 나타낸 것이다.
도 12는 AWS 위치에서의 감쇠 보정 전의 엑스밴드 레이더 반사도와 에스밴드 레이더 반사도 간의 산포도를 나타낸 것이다.
도 13은 감쇠 보정한 엑스밴드 레이더 반사도와 에스밴드 레이더 반사도 간의 산포도를 나타낸 것이다.
도 14는 2016년 7월 5일의 대류운 사례에서 감쇠 보정 전의 엑스밴드 레이더 반사도와 에스밴드 레이더 반사도 간의 산포도를 나타낸 것이다.
도 15는 감쇠 보정 후의 엑스밴드 레이더 반사도와 에스밴드 레이더 반사도 간의 산포도를 나타낸 것이다.
도 16은 2016년 5월 2일의 층상운 사례에서 감쇠 보정 전의 엑스밴드 레이더 반사도와 에스밴드 레이더 반사도 간의 산포도를 나타낸 것이다.
도 17은 감쇠 보정 후의 엑스밴드 레이더 반사도와 에스밴드 레이더 반사도 간의 산포도를 나타낸 것이다.
도 18은 본 발명에 따른 다중 지상 통신 기지국 마이크로파를 활용한 엑스밴드 이중 편파 레이더 반사도 보정의 순서도이다.1 is a conceptual diagram of an X-band dual polarization radar reflectivity correction device using microwaves of a multi-terrestrial communication base station according to the present invention.
2 shows the X-band radar reflectivity (Plan Position Indicator, PPI) before attenuation correction of the Korea Institute of Civil Engineering and Building Technology in the case of convective cloud at 7:00 on July 5, 2016.
Figure 3 shows the S-band radar reflectivity (PPI) of the Korea Meteorological Administration.
4 is an optimal attenuation correction coefficient calculated by applying seven microwave link attenuations from Equation 1 to Equation 9

It shows the X-band radar attenuation field calculated by applying and b to Equation 6.
5 is the magnitude of attenuation for each calculated X-band radar gate

It shows the X-band radar reflectivity obtained by applying attenuation correction to Equation 10.
6 shows a scatter diagram between the X-band radar reflectivity and the S-band radar reflectivity before attenuation correction at the AWS location operated by the Korea Meteorological Administration in Seoul.
7 shows a scatter diagram between attenuation-corrected X-band radar reflectivity and S-band radar reflectivity.
8 shows the X-band radar reflectivity (PPI) before attenuation correction of the Korea Institute of Civil Engineering and Building Technology at 22:00 on May 2, 2016, which is a case of stratified clouds.
9 shows S-band radar reflectivity (PPI) of the Korea Meteorological Administration.
10 shows an X-band radar attenuation field calculated by applying an optimal attenuation correction coefficient calculated by applying Equation 1 to Equation 9 to seven microwave link attenuations and applying Equation 6.
11 is the magnitude of attenuation for each calculated X-band radar gate

It shows the X-band radar reflectivity obtained by applying attenuation correction to Equation 10.
12 shows a scatter diagram between the X-band radar reflectivity and the S-band radar reflectivity before attenuation correction at the AWS location.
13 shows a scatter diagram between attenuation-corrected X-band radar reflectivity and S-band radar reflectivity.
14 shows a scatter diagram between the X-band radar reflectivity and the S-band radar reflectivity before attenuation correction in the case of convective cloud on July 5, 2016.
15 shows a scatter diagram between X-band radar reflectivity and S-band radar reflectivity after attenuation correction.
16 shows a scatter diagram between the X-band radar reflectivity and the S-band radar reflectivity before attenuation correction in the case of stratified clouds on May 2, 2016.
17 shows a scatter diagram between X-band radar reflectivity and S-band radar reflectivity after attenuation correction.
18 is a flowchart of X-band dual polarization radar reflectivity correction using microwaves of a multi-terrestrial communication base station according to the present invention.

The above objects, features and advantages will be described later in detail with reference to the accompanying drawings, and accordingly, those skilled in the art to which the present invention belongs will be able to easily implement the technical spirit of the present invention. In describing the present invention, if it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

1 is a conceptual diagram of an X-band dual polarization radar reflectivity correction device using microwaves of a multi-terrestrial communication base station according to the present invention.

)를 산출하는 마이크로파 감쇠 산출 모듈(200), 마이크로파 감쇠 자료를 기반으로 강우 유무를 탐지하는 강우 유무 탐지 모듈(300), 및 감쇠 보정 계수로 엑스밴드 레이더의 반사도를 보정하는 반사도 보정 모듈(400)을 포함한다.As shown in FIG. 1, the X-band dual polarization radar reflectivity correction apparatus using microwaves of a multi-terrestrial communication base station according to the present invention uses the difference between the transmission power and the reception power of the observation data collection module 100 and the microwave link. by microwave attenuation (rainfall-caused attenuation,

A microwave attenuation calculation module 200 that calculates ), a rain presence detection module 300 that detects whether or not there is rain based on the microwave attenuation data, and a reflectivity correction module 400 that corrects the reflectivity of the X-band radar with an attenuation correction coefficient. includes

Table 1 shows the characteristics of seven microwave links to be input to the observation data collection module according to the present invention and the name of an automatic weather station (AWS) point installed closest to the receiving antenna of each microwave link.

Link
name Nearest
AWS Frequency
(GHz) Power
(dBm) Link Length (km) Signal resolution Time resolution HG 419 8.06 29 21.1 0.01 dBm 15 seconds GH 413 7.75 29 21.1 WM 401 6.32 29 5.7 MW 401 6.06 29 5.7 MH 401 8.26 30 17.6 HM 421 7.95 30 17.6 MB 425 6.23 30 37.4

The present invention collects the transmit power and receive power of 7 microwave links at 15 second intervals with a resolution of 0.01 dB, and utilizes microwaves with relatively long wavelengths of 10 GHz or less to use them as reference values for X-band radar reflectivity correction. .

Table 2 shows the characteristics of the Korea Institute of Civil Engineering and Building Technology's X-band dual polarization radar and the Korea Meteorological Administration's S-band single polarization radar.

Parameters KICT radar GDK radar Location 37.67°N, 126.74°E 38.1173°N, 127.4336°E Transmitter type Magnetron Klystron Antenna Diameter 1.8m 8.5 m Frequency 9410±30 MHz 2887 MHz Peak power 8 kW 850 kW Pulse width 0.6 µsec 0.8 μsec & 4.5 μsec Pulse repetition frequency 2000Hz 250 to 1200Hz Gain 41 dB 45 dB Time resolution 1 min 10min Spatial resolution 60m 250m Antenna polarization Simultaneous H/V Simultaneous H Effective observation range 40km 240 km Beam width 1.4° 1°

The observation data collection module 100 receives and collects observation data for X-band radar reflectivity correction. Here, the observation data collected by the observation data collection module 100 is the transmission power and reception power of the microwave link, and the rainfall time recorded by the rainfall detector of the Automatic Weather System (AWS) of the Korea Meteorological Administration installed around the microwave link. It includes cumulative rainfall and rainfall time data recorded by rain gauges, X-band radar reflectivity, and S-band radar reflectivity. In addition, in order to collect this, the observation data collection module 100 includes a microwave link data collection module that collects transmission power and reception power of the microwave link, and rainfall recorded in a rain sensor of the automatic weather observation equipment of the Korea Meteorological Administration installed around the microwave link. A rainfall detector data collection module that collects duration data, an X-band radar data collection module that collects the reflectivity of the X-band radar of the Korea Institute of Civil Engineering and Building Technology and differential phase difference variables, and an S-band that collects the reflectivity of the Gwangdeoksan S-band radar of the Korea Meteorological Administration. It includes a radar data collection module.

)를 산출한다. 여기서, 마이크로파 감쇠 산출 모듈(200)은 15초 해상도의 마이크로파 링크의 송신 전력과 수신 전력 간의 차이를 이용하여 마이크로파 감쇠를 산출한다.The microwave attenuation calculation module 200 uses the difference between the transmit power and the received power of the microwave link to determine the microwave attenuation (rainfall-caused attenuation,

) is calculated. Here, the microwave attenuation calculation module 200 calculates the microwave attenuation using the difference between the transmission power and the reception power of the microwave link with 15 second resolution.

)를 산출하는 평균 마이크로파 감쇠 산출 모듈(320), 결정된 창 크기 동안의 마이크로파 감쇠와 평균 마이크로파 감쇠(

)간의 차이를 이용하여 마이크로파 감쇠의 검정 통계량을 산출하는 마이크로파 감쇠의 검정 통계량 산출 모듈(330), 마이크로파 감쇠를 이용한 강우 유무를 1차적으로 판단하기 위해 필요한 임계 값을 결정하는 임계 값

산출 모듈, 마이크로파 감쇠의 검정 통계량과 임계 값 간의 초과 여부를 통해 1차적으로 강우 유무를 탐지하는 1차 강우 유무 탐지 모듈(350), 1차적으로 결정된 강우 유무 탐지 결과와 특정 창 크기 동안의 평균 마이크로파 감쇠(

)를 이용하여 마이크로파 기준 감쇠(Ad)를 실시간으로 산출하는 마이크로파 기준 감쇠 산출 모듈(360), 마이크로파 감쇠와 마이크로파 기준 감쇠 간의 초과 여부를 통해 2차적으로 강우 유무를 탐지하는 2차 강우 유무 탐지 모듈(370)을 포함한다.The rain presence/absence detection module 300 detects the presence/absence of rain based on the microwave attenuation data. To this end, the rain presence detection module 300 includes a window size calculation module 310 that determines, as a moving time window (Wt), the minimum delay time at which the autocorrelation coefficient of microwave attenuation according to the rain characteristics is 0.65 or more, and , the average microwave attenuation over the determined window size (

) Average microwave attenuation calculation module 320 that calculates the microwave attenuation and the average microwave attenuation for the determined window size

) Microwave attenuation test statistic calculation module 330 that calculates the test statistic of microwave attenuation using the difference between them, and a threshold value that determines a threshold required to primarily determine whether or not there is rain using microwave attenuation.

A calculation module, a primary rain presence/absence detection module 350 that primarily detects whether or not there is rain through a test statistic of microwave attenuation and whether or not it exceeds a threshold, the primarily determined rainfall presence/absence detection result and the average microwave for a specific window size attenuation(

), a microwave reference attenuation calculation module 360 that calculates the microwave reference attenuation (Ad) in real time, and a secondary rainfall presence/absence detection module that secondarily detects the presence or absence of rainfall through whether or not the microwave attenuation exceeds the microwave reference attenuation ( 370).

The window size calculation module 310 determines the minimum delay time at which the autocorrelation coefficient of microwave attenuation shows a statistically significant value, for example, 0.65, based on the microwave attenuation data calculated by the microwave attenuation calculation module 200, as the window size. (moving time window, Wt).

Here, the autocorrelation coefficient is equal to Equation 1 below.

이고,

는 지연시간을 나타낸다.In Equation 1,

ego,

represents the delay time.

)를 산출한다.The average microwave attenuation calculation module 320 averages the microwave attenuation for the window size determined by the window size calculation module 310 and averages the microwave attenuation at 1-minute intervals (

) is calculated.

)는 창 크기(Wt)내의 마이크로파 감쇠 크기의 평균이며, 아래의 수학식 2와 같다.Here, the average microwave attenuation (

) is the average of the microwave attenuation in the window size (Wt), and is shown in Equation 2 below.

는 실시간 측정되는 마이크로파 감쇠 크기(k) 이며,

는 창 크기(Wt)내의 마이크로파 감쇠 자료 개수이다.In Equation 2,

is the microwave attenuation magnitude (k) measured in real time,

is the number of microwave attenuation data within the window size (Wt).

)와, 평균 마이크로파 감쇠 산출 모듈(320)에서 산출된 평균 마이크로파 감쇠(

)의 차이를 이용하여 마이크로파 감쇠의 검정 통계량을 산출한다. 여기서, 마이크로파 감쇠의 검정 통계량(

)은 아래의 수학식 3과 같다.The microwave attenuation test statistic calculation module 330 calculates the microwave attenuation calculated by the microwave attenuation calculation module 200 (

) and the average microwave attenuation calculated by the average microwave attenuation calculation module 320 (

) is used to calculate the test statistic of microwave attenuation. Here, the test statistic of microwave attenuation (

) is equal to Equation 3 below.

)과 마이크로파 감쇠의 표준 편차는 상호 수렴하지 않는다.

는 창 크기(Wt)내의 마이크로파 감쇠의 평균이다.In Equation 3, since microwave attenuation is nonstationary, the test statistic of microwave attenuation (

) and the standard deviation of microwave attenuation do not converge.

is the average of the microwave attenuation within the window size (Wt).

)을 산출한다. 본 실시예는 강우 감지기 자료와 비교하여 90% 이상의 일치를 보이는 임계값을 최종 임계값(

)으로 결정하는 것을 예시하며, 이는 0.09인 것을 예시한다.The threshold value calculation module 340 determines the threshold value (

) is calculated. In this embodiment, the threshold that shows a match of 90% or more compared to the rain sensor data is the final threshold (

), which is 0.09.

)과, 임계 값 산출 모듈(340)에서 산출된 임계값 간의 초과 여부를 통해 1차적으로 강우 유무를 탐지한다. 즉, 창 크기(Wt)가 결정되면 임계값(

)이 결정되고, 아래의 수학식 4에 의해 1차적으로 마이크로파 감쇠를 이용한 강우 유무, 즉, 1차 강우 유무가 결정된다.The primary rainfall presence/absence detection module 350 determines the test statistic of microwave attenuation (

) and whether or not the threshold value calculated by the threshold value calculation module 340 is exceeded is primarily detected whether or not there is rainfall. That is, when the window size (Wt) is determined, the threshold value (

) is determined, and the presence or absence of rainfall using microwave attenuation is primarily determined by Equation 4 below, that is, the presence or absence of primary rainfall.

)와, 1차 강우 유무 탐지 모듈(350)에서 탐지된 1차 강우 유무 탐지 결과를 이용하여 마이크로파 기준 감쇠(Ad)를 실시간으로 산출한다. 여기서, 마이크로파 기준 감쇠(Ad)는 아래의 수학식 5와 같이 산출된다.The microwave reference attenuation calculation module 360 calculates the average microwave attenuation (calculated by the average microwave attenuation calculation module 320).

) and the first rain detection result detected by the first rain detection module 350, the microwave reference attenuation (Ad) is calculated in real time. Here, the microwave reference attenuation (Ad) is calculated as in Equation 5 below.

)가 마이크로파 기준 감쇠 산출 모듈(360)에서 산출된 마이크로파 기준 감쇠와의 차이가 마이크로파 감쇠 크기의 2.5%보다 클 때 강우에 의해 야기된 마이크로파 감쇠(

)로 결정한다.When the magnitude of the microwave attenuation exceeds the microwave reference attenuation (Ad) calculated in real time, it is determined to be caused by rainfall. The presence or absence of rainfall is finally determined secondarily by correcting the result of whether or not there is rain primarily determined according to whether the microwave attenuation and the microwave standard attenuation (Ad) are exceeded. The microwave attenuation calculation module 200 caused by rainfall is the microwave attenuation calculated by the microwave attenuation calculation module 200 (

(

) to determine

)와 마이크로파 기준 감쇠(Ad)간의 초과 여부를 통해 결정된 1차 강우 유무 탐지 결과를 보정하는 2차 강우 유무를 탐지한다. 여기서, 마이크로파 기준 감쇠(Ad)는 창 크기 내의 마이크로파 감쇠의 평균이며, 창 크기 내의 마이크로파 기준 감쇠와 큰 차이를 보이는 마이크로파 감쇠(

)는 강우가 내렸을 때의 마이크로파 감쇠(

)로 결정하기 위해 사용된다. 최종적으로 2차 강우 유무 탐지 모듈(370)에서 마이크로파 감쇠(

)를 이용한 강우 유무 탐지를 결정한다. 또한, 마이크로웨이브 링크 송신 및 수신 안테나로부터 가장 근접하게 설치된 자동기상관측장비(AWS)의 강우 감지기에 강우로 기록된 시간 자료와 비교하여 이를 검증한다.The secondary rainfall presence detection module 370 attenuates microwaves (

) and the microwave standard attenuation (Ad), the secondary rainfall presence or absence is detected to correct the primary rainfall presence/absence detection result determined through the excess. Here, the microwave reference attenuation (Ad) is the average of the microwave attenuation within the window size, and the microwave attenuation with a large difference from the microwave reference attenuation within the window size (

) is the microwave attenuation (

) is used to determine Finally, the microwave attenuation in the secondary rainfall presence detection module 370 (

) to determine the presence or absence of rainfall. In addition, it is verified by comparing with the time data recorded as rainfall in the rainfall detector of the automatic weather observation equipment (AWS) installed closest to the microwave link transmission and reception antennas.

)를 연산하는 엑스밴드 레이더 게이트 별 감쇠 크기 연산 모듈(420)과, 엑스밴드 레이더 평균 감쇠 크기(

)를 산출하는 엑스밴드 레이더 평균 감쇠 크기 산출 모듈(430), 레이더 주파수로 변환된 마이크로파 감쇠 크기(

)를 산출하는 마이크로파 감쇠 크기 산출 모듈(440), 비용함수(

)를 산출하는 비용함수 산출 모듈(450), 및 엑스밴드 레이더 반사도를 보정하는 엑스밴드 레이더 반사도 보정 모듈(460)을 포함한다.The reflectivity correction module 400 corrects the reflectivity of the X-band radar by calculating an attenuation correction coefficient. To this end, the reflectivity correction module 400 includes the microwave attenuation determination module 410 and the attenuation size for each X-band radar gate r (

), and an X-band radar average attenuation size (

) X-band radar average attenuation size calculation module 430 that calculates, microwave attenuation size converted to radar frequency (

), a microwave attenuation size calculation module 440 that calculates a cost function (

), and an X-band radar reflectivity correction module 460 for correcting X-band radar reflectivity.

)로 결정한다.The microwave attenuation determination module 410 determines the microwave attenuation that exceeds the microwave reference attenuation is the microwave attenuation caused by the rain (

) to determine

)를 연산한다. 여기서, 엑스밴드 레이더 게이트 별 감쇠 크기는 아래의 수학식 6과 같다. 이중 편파 레이더가 도입된 이래로 엑스밴드 레이더 감쇠 크기(

)는 차등 위상차(

)의 합이 전파 경로를 따라 축적된 값으로 가정하고 계산한다. 차등 위상차는 수평 편파 위상과 수직 편파 위상의 차이를 의미하는데 전파 경로 누적 감쇠는 차등 위상차의 총합이라는 가정으로 감쇠를 추정한다.The attenuation size per X-band radar gate calculation module 420 is the attenuation size per X-band radar gate (r) (

) is computed. Here, the magnitude of attenuation for each X-band radar gate is as shown in Equation 6 below. Since the introduction of dual polarization radar, the magnitude of the X-band radar attenuation (

) is the differential phase difference (

) is assumed to be the accumulated value along the propagation path. The differential phase difference means the difference between the horizontal polarization phase and the vertical polarization phase, and the attenuation is estimated by assuming that the propagation path cumulative attenuation is the sum of the differential phase differences.

와

은 특정 레이더 방위각에서 반사도가 30dBZ 이상을 보이는 첫 번째 게이트와 마지막 게이트를 의미한다. r은 해당되는 게이트이다.

은 레이더의 게이트 간격(km)이며, 레이더 전자기파의 왕복 거리를 고려하기 위해서 2를 곱한다. 엑스밴드 레이더 게이트(r)별 감쇠 크기(

)는 아래의 수학식 7과 같이 계산한다. In Equation 6,

Wow

denotes the first and last gates whose reflectivity is greater than 30 dBZ at a specific radar azimuth. r is the corresponding gate.

is the gate distance (km) of the radar, multiplied by 2 to consider the round-trip distance of radar electromagnetic waves. Attenuation size for each X-band radar gate (r) (

) is calculated as in Equation 7 below.

이며,

이다. 또한,

는 측정된 엑스밴드 레이더의 반사도 자료이며,

, b는 경험적으로 결정되는 레이더 감쇠 보정 계수이다.

는 0.13에서 0.34까지 변화하며, 본 실시예는

로 0.14를 예시한다.In Equation 7,

is,

to be. also,

is the reflectivity data of the measured X-band radar,

, b is the radar attenuation correction factor determined empirically.

changes from 0.13 to 0.34, and this embodiment

0.14 is exemplified by

, b 계수를 결정하기 위해서 아래의 수학식 8과 같이 마이크로파 링크 경로 길이에 해당하는 엑스밴드 레이더 평균 감쇠 크기(

)를 계산한다.The X-band radar average attenuation magnitude calculation module 430 optimizes

, in order to determine the b coefficient, the X-band radar average attenuation size corresponding to the microwave link path length as shown in Equation 8 below (

) is calculated.

은 마이크로파 링크의 경로 길이에 해당하는 가장 인접한 레이더 게이트의 전체 개수이다.In Equation 8,

is the total number of nearest radar gates corresponding to the path length of the microwave link.

)를 산출한다. 마이크로파 링크의 주파수와 엑스밴드 레이더 주파수가 다를 경우, 마이크로파 링크의 감쇠 크기(

에 마이크로파 링크 주파수와 엑스밴드 레이더 주파수의 비를 곱하여 마이크로파 감쇠 크기(

)를 아래의 수학식 9와 같이 변환하고, 레이더 감쇠 보정 계수

를 결정하기 위한 기준 값으로 사용한다.The microwave attenuation magnitude calculation module 440 converts the microwave attenuation magnitude into the radar frequency (

) is calculated. When the frequency of the microwave link and the frequency of the X-band radar are different, the attenuation of the microwave link (

is multiplied by the ratio of the microwave link frequency and the X-band radar frequency,

) is converted as shown in Equation 9 below, and the radar attenuation correction coefficient

is used as a reference value for determining

)와 변환된 마이크로파 감쇠 크기(

)간의 차이를 계산하여 아래의 수학식 10과 같이 비용함수(

)가 최소일 때의 감쇠 보정 계수를 최적의 감쇠 보정 계수로 결정한다.The cost function calculation module 450 is the average attenuation size of the X-band radar (

) and the converted microwave attenuation magnitude (

) by calculating the difference between the cost function (as shown in Equation 10 below)

) is determined as the optimal damping correction coefficient.

를 산출하기 위해서 황금분할탐색방법을 적용하였다. 황금분할탐색방법으로 최적의 감쇠 보정 계수

를 산출하는 과정은 먼저 두 감쇠 보정 계수 (

,

) 구간을 선택하고 구간 내의 감쇠 보정 계수(

,

)를 결정하기 위해

의 차이에 황금 비율인 0.618을 곱한 분리 거리(d)를 계산하고,

는

와 분리거리(d)의 차이 값으로 정의하고,

은

과 분리거리(d)의 합으로 정의하였다. 만약

를 레이더의 평균 감쇠 크기(

)계산에 필요한 감쇠 보정 계수

값으로 사용하고 수학식 10에 적용하여 산출한 비용함수

(

)가

을 사용하여 산출한 비용함수

(

)보다 크다면,

을

값으로 대체하고, 반대이면

를

값으로 대체하면 두 감쇠 보정 계수 (

,

)의 차이는 분리 거리(d)만큼 좁아진다. 반복 과정을 몇 번 거치면 두 감쇠 보정 계수 (

,

)의 거리는 0에 근접하게 되는데 그 때의 감쇠 보정 계수를 최적의 감쇠 보종 계수로 결정하였다. 감쇠 보정 계수

의 초기값으로

과

를 각각 0.1, 0.5으로 설정하였고 b는 1.0으로 상수로 사용하였다.Optimal attenuation correction factor

To calculate , the golden partition search method was applied. Optimal damping correction coefficient by golden partition search method

The process of calculating is first two attenuation correction coefficients (

,

) section and select the attenuation correction factor (

,

) to determine

Calculate the separation distance (d) by multiplying the difference of 0.618, which is the golden ratio,

Is

Defined as the difference between and the separation distance (d),

silver

It was defined as the sum of and the separation distance (d). if

the average attenuation magnitude of the radar (

) attenuation correction factor required to calculate

The cost function calculated by using it as a value and applying Equation 10

(

)go

The cost function calculated using

(

) is greater than

second

Substitute the value, and vice versa

cast

Substituting the values for the two attenuation correction factors (

,

) is narrowed by the separation distance (d). After a few iterations, the two attenuation correction factors (

,

) is close to 0, and the attenuation correction coefficient at that time was determined as the optimal attenuation correction coefficient. Attenuation correction factor

with an initial value of

class

were set to 0.1 and 0.5, respectively, and b was used as a constant at 1.0.

와 감쇠 보정 계수

, b를 적용하여 계산한 게이트(r)별 엑스밴드 레이더 감쇠 크기

를 이용하여 엑스밴드 레이더 반사도를 보정한다. 이는 아래의 수학식 11과 같이 감쇠 보정한 레이더 반사도

를 산출하여 수행할 수 있다.X-band radar reflectivity correction module 460 is a radar reflectivity

and the attenuation correction factor

X-band radar attenuation for each gate (r) calculated by applying , b

Correct the X-band radar reflectivity using This is the attenuation-corrected radar reflectivity as shown in Equation 11 below.

It can be performed by calculating

와 b를 수학식 6에 적용하여 산출한 엑스밴드 레이더 감쇠장을 나타낸 것이다. 도 5는 산출한 엑스밴드 레이더 게이트 별 감쇠 크기

를 수학식 10에 적용하여 감쇠 보정한 엑스밴드 레이더 반사도를 나타낸 것이다. 도 6은 기상청이 서울시에서 운영중인 AWS 위치에서의 감쇠 보정 전의 엑스밴드 레이더 반사도와 에스밴드 레이더 반사도 간의 산포도를 나타낸 것이다. 도 7은 감쇠 보정한 엑스밴드 레이더 반사도와 에스밴드 레이더 반사도 간의 산포도를 나타낸 것이다. 도 2는 2016년 7월 5일 7시의 대류운 사례에서 한국건설기술연구원의 감쇠 보정 전의 엑스밴드 레이더 반사도(Plan Position Indicator, PPI)를 나타낸 것이다. 층상운 사례에 비해 40 dBZ이상의 국지적인 강우 셀의 반사도를 보였다. 도 3은 기상청의 에스밴드 레이더 반사도(PPI)를 나타낸 것이다. 도 4는 7개의 마이크로파 링크 감쇠를 수학식 1에서 수학식 9까지 적용하여 산출한 최적의 감쇠 보정 계수

와 b를 수학식 6에 적용하여 산출한 엑스밴드 레이더 감쇠장을 나타낸 것이다. 최대 15 dB이상의 감쇠 크기를 보였다. 도 5는 산출한 엑스밴드 레이더 게이트 별 감쇠 크기

를 수학식 10에 적용하여 감쇠 보정한 엑스밴드 레이더 반사도를 나타낸 것이다. 감쇠 보정 후 에스밴드 레이더 반사도와 공간 분포가 상당히 일치하는 것을 확인할 수 있다. 도 6은 기상청이 서울시에서 운영중인 AWS 위치에서의 감쇠 보정 전의 엑스밴드 레이더 반사도와 에스밴드 레이더 반사도 간의 산포도를 나타낸 것이다. 절대 평균 오차(Mean Absolute Error, MAE)는 16.2 dB, RMSE는 17.7 dB 그리고 상관계수는 0.7를 보여 에스밴드 레이더 반사도에 비해 강우 감쇠로 인해 과소 측정된 것을 알 수 있다. 도 7은 감쇠 보정한 엑스밴드 레이더 반사도와 에스밴드 레이더 반사도 간의 산포도를 나타낸 것인데, 절대 평균 오차가 16.2 dB에서 6.7 dB로 크게 감소하였고 RMSE는 17.7 dB에서 8.2 dB로 감소하였으며 상관 계수는 0.7에서 0.8로 증가한 것을 확인하였다.2 shows the X-band radar reflectivity (Plan Position Indicator, PPI) before attenuation correction of the Korea Institute of Civil Engineering and Building Technology in the case of convective cloud at 7:00 on July 5, 2016. Figure 4 shows the S-band radar reflectivity (PPI) of the Korea Meteorological Administration. 5 is an optimal attenuation correction coefficient calculated by applying seven microwave link attenuations from Equation 1 to Equation 9

It shows the X-band radar attenuation field calculated by applying and b to Equation 6. 5 is the magnitude of attenuation for each calculated X-band radar gate

It shows the X-band radar reflectivity obtained by applying attenuation correction to Equation 10. 6 shows a scatter diagram between the X-band radar reflectivity and the S-band radar reflectivity before attenuation correction at the AWS location operated by the Korea Meteorological Administration in Seoul. 7 shows a scatter diagram between attenuation-corrected X-band radar reflectivity and S-band radar reflectivity. 2 shows the X-band radar reflectivity (Plan Position Indicator, PPI) before attenuation correction of the Korea Institute of Civil Engineering and Building Technology in the case of convective cloud at 7:00 on July 5, 2016. Compared to the stratified cloud case, the reflectivity of the local rain cell was shown to be greater than 40 dBZ. Figure 3 shows the S-band radar reflectivity (PPI) of the Korea Meteorological Administration. 4 is an optimal attenuation correction coefficient calculated by applying seven microwave link attenuations from Equation 1 to Equation 9

It shows the X-band radar attenuation field calculated by applying and b to Equation 6. The maximum attenuation was greater than 15 dB. 5 is the magnitude of attenuation for each calculated X-band radar gate

It shows the X-band radar reflectivity obtained by applying attenuation correction to Equation 10. After attenuation correction, it can be seen that the S-band radar reflectivity and spatial distribution are quite consistent. 6 shows a scatter diagram between the X-band radar reflectivity and the S-band radar reflectivity before attenuation correction at the AWS location operated by the Korea Meteorological Administration in Seoul. The mean absolute error (MAE) was 16.2 dB, the RMSE was 17.7 dB, and the correlation coefficient was 0.7, indicating that it was undermeasured due to rain attenuation compared to the S-band radar reflectivity. Figure 7 shows the scatter plot between the attenuation-corrected X-band radar reflectivity and the S-band radar reflectivity. It was confirmed that it increased to .

를 수학식 10에 적용하여 감쇠 보정한 엑스밴드 레이더 반사도를 나타낸 것이다. 도 12는 AWS 위치에서의 감쇠 보정 전의 엑스밴드 레이더 반사도와 에스밴드 레이더 반사도 간의 산포도를 나타낸 것이다. 도 13은 감쇠 보정한 엑스밴드 레이더 반사도와 에스밴드 레이더 반사도 간의 산포도를 나타낸 것이다.8 shows the X-band radar reflectivity (PPI) before attenuation correction of the Korea Institute of Civil Engineering and Building Technology at 22:00 on May 2, 2016, which is a case of layered cloud, and FIG. 9 shows the S-band radar reflectivity (PPI) of the Korea Meteorological Administration. . 10 shows an X-band radar attenuation field calculated by applying an optimal attenuation correction coefficient calculated by applying Equation 1 to Equation 9 to seven microwave link attenuations and applying Equation 6. 11 is the magnitude of attenuation for each calculated X-band radar gate

It shows the X-band radar reflectivity obtained by applying attenuation correction to Equation 10. 12 shows a scatter diagram between the X-band radar reflectivity and the S-band radar reflectivity before attenuation correction at the AWS location. 13 shows a scatter diagram between attenuation-corrected X-band radar reflectivity and S-band radar reflectivity.

를 수학식 10에 적용하여 감쇠 보정한 엑스밴드 레이더 반사도를 나타낸 것이다. 감쇠 보정 후 에스밴드 레이더 반사도와 공간 분포가 상당히 일치하는 것을 확인할 수 있다. 도 12는 AWS 위치에서의 감쇠 보정 전의 엑스밴드 레이더 반사도와 에스밴드 레이더 반사도 간의 산포도를 나타낸 것이다. 절대 평균 오차는 8.9 dB, RMSE는 10.3 Db 그리고 상관 계수는 0.3을 보여 과소 측정된 것을 알 수 있다. 도 13은 감쇠 보정한 엑스밴드 레이더 반사도와 에스밴드 레이더 반사도 간의 산포도를 나타낸 것인데, 절대 평균 오차가 8.9 dB에서 3.1 dB 감소하였고 RMSE는 10.3 dB에서 3.7 dB로 감소하였으며 상관 계수는 0.3에서 0.7로 증가하였다.8 shows the X-band radar reflectivity (PPI) before attenuation correction of the Korea Institute of Civil Engineering and Building Technology at 22:00 on May 2, 2016, which is a case of stratified clouds. 9 shows S-band radar reflectivity (PPI) of the Korea Meteorological Administration. Since the S-band radar electromagnetic wave is not greatly attenuated by precipitation, it can be seen that the size is relatively large compared to the X-band radar reflectivity. 10 shows an X-band radar attenuation field calculated by applying an optimal attenuation correction coefficient calculated by applying Equation 1 to Equation 9 to seven microwave link attenuations and applying Equation 6. The maximum attenuation was less than 12 dB. 11 is the magnitude of attenuation for each calculated X-band radar gate

It shows the X-band radar reflectivity obtained by applying attenuation correction to Equation 10. After attenuation correction, it can be seen that the S-band radar reflectivity and spatial distribution are quite consistent. 12 shows a scatter diagram between the X-band radar reflectivity and the S-band radar reflectivity before attenuation correction at the AWS location. The absolute average error was 8.9 dB, the RMSE was 10.3 Db, and the correlation coefficient was 0.3, indicating an underestimation. 13 shows the scatter plot between attenuation-corrected X-band radar reflectivity and S-band radar reflectivity. The absolute mean error decreased from 8.9 dB to 3.1 dB, the RMSE decreased from 10.3 dB to 3.7 dB, and the correlation coefficient increased from 0.3 to 0.7. did

14 shows the scatter diagram between the X-band radar reflectivity and the S-band radar reflectivity before attenuation correction in the case of convective cloud on July 5, 2016, and FIG. 15 shows the scatter diagram between the X-band radar reflectivity and the S-band radar reflectivity after attenuation correction it is shown 16 shows a scatter diagram between the X-band radar reflectivity and the S-band radar reflectivity before attenuation correction in the case of stratified clouds on May 2, 2016. 17 shows a scatter diagram between X-band radar reflectivity and S-band radar reflectivity after attenuation correction.

14 shows a scatter diagram between the X-band radar reflectivity and the S-band radar reflectivity before attenuation correction in the case of convective cloud on July 5, 2016. The black symbol shows the scatter plot between reflectivities in AWS located within a radius of 10 km from the center of the X-band radar, the yellow symbol shows the scatter plot between reflectivities within a radius of 20 km, the blue symbol shows the scatter plot between the reflectivities within a radius of 30 km, and the red symbol shows the scatter plot within a radius of 40 km. It shows the scatter plot between reflectances. The absolute average error between the X-band radar and the S-band radar reflectivity before attenuation correction was 17.9 dB, the RMSE was 20.6 dB, and the correlation coefficient was 0.4. 15 shows a scatter diagram between X-band radar reflectivity and S-band radar reflectivity after attenuation correction. After attenuation correction, the absolute error between the X-band radar and the S-band radar reflectivity significantly decreased from 17.9 dB to 8.4 dB, the RMSE decreased from 20.6 dB to 10.8 dB, and the correlation coefficient increased from 0.4 to 0.7. 16 shows a scatter diagram between the X-band radar reflectivity and the S-band radar reflectivity before attenuation correction in the case of stratified clouds on May 2, 2016. The absolute average error between X-band radar and S-band radar reflectivity before attenuation correction was 6.4 dB, RMSE was 8.1 dB, and the correlation coefficient was 0.6. 17 shows a scatter diagram between X-band radar reflectivity and S-band radar reflectivity after attenuation correction. The absolute average error between the X-band radar and S-band radar reflectivity after attenuation correction decreased from 6.4 dB before attenuation correction to 6.3 dB, and the RMSE decreased from 8.1 dB to 7.9 dB. It can be seen that the attenuation correction effect is greater in the convective cloud case than in the stratified cloud case.

Next, the attenuation-corrected X-band radar reflectivity was verified using the X-band dual polarization radar reflectivity correction device using microwaves of a multi-terrestrial communication base station according to the present invention.

In order to verify the attenuation-corrected X-band radar reflectivity, comparison and verification were performed with the S-band radar reflectivity data. was assumed. First, since the difference in horizontal distance between the two radars is several hundred km, a difference in beam height occurs due to the earth curvature effect. Therefore, in the present invention, as shown in Table 3, the height of the S-band radar elevation angle (0 to 1.7°) beam was adjusted to minimize the difference between the beams of the X-band radar elevation angle (5°).

AWS
Site KICT
RBH (km) GDK
RBH (km) / Elevation angle (°) AWS
Site KICT
RBH (km) GDK
RBH (km) / Elevation angle (°) 116 2.8 2.7/1.0 411 2.0 2.2/0.6 400 2.9 2.6/1.0 413 2.9 2.6/1.0 401 2.9 2.8/1.0 414 2.1 2.0/0.6 402 3.4 3.3/1.7 415 2.4 2.2/0.6 403 3.2 3.5/1.7 416 1.6 1.5/0.2 404 1.5 1.4/0.0 417 2.4 2.3/0.6 405 1.9 1.9/0.3 418 2.2 2.3/0.6 406 2.2 2.3/1.0 419 2.2 2.1/0.6 407 2.8 3.1/1.7 421 2.7 2.6/1.0 408 2.6 2.5/1.0 423 2.0 1.9/0.3 409 2.9 3.2/1.7 424 1.9 1.9/0.6 410 2.3 2.3/0.6 425 2.9 2.8/1.0 506 0.9 1.3/0.0 509 2.6 2.7/1.0 510 1.9 1.8/0.3 532 2.3 2.1/1.0 540 1.2 1.3/0.0 541 3.3 2.9/1.7 544 1.9 2.0/0.3 569 3.2 3.1/1.7 572 3.5 3.7/1.7 589 0.3 1.4/0.0 590 3.2 2.9/1.0 599 3.4 2.4/1.7

The wavelength of the X-band radar electromagnetic wave is 2.5 to 4 cm, the wavelength of the S-band radar electromagnetic wave is 8 to 15 cm, and the diameter of precipitation particles is several mm, and snowflakes and hail are several mm to several cm. Similar. When observed by a weather radar with a wavelength of several cm, Rayleigh scattering occurs in raindrops with a wavelength of several mm, and Rayleigh scattering or Mie scattering occurs in snowflakes or hailstones with a diameter of several mm to several cm. The S-band radar reflectivity was converted to the X-band radar reflectivity using Equation 12 below.

는 에스밴드 레이더 반사도이며,

는 에스밴드 레이더 반사도(

)가 엑스밴드 레이더 파장으로 변환되었을 때의 반사도이다. 에스밴드 레이더 반사도가 25dBZ 이하일 때는

식에 적용하여 반사도 변환을 하였고, 에스밴드 레이더 반사도가 25dBZ 에서 45dBZ 사이일 경우에는

식을 적용하였고, 45dBZ 이상일 경우에는

식을 적용하여 변환하였다.In Equation 12,

is the S-band radar reflectivity,

is the S-band radar reflectivity (

) is the reflectivity when converted to X-band radar wavelength. When the S-band radar reflectivity is less than 25 dBZ

The reflectivity was converted by applying to the equation, and when the S-band radar reflectivity was between 25dBZ and 45dBZ,

The formula was applied, and in the case of more than 45dBZ

It was converted by applying Eq.

The height difference of the radar beam and the wavelength difference between the X-band and S-band radars were considered, and other differences were assumed to be negligible. Quantitative verification was performed statistically using the following formula.

를 결정하기 위해 레이더 반경 내에 위치한 7개의 마이크로파 링크 감쇠 자료를 모두 이용하는 방법을 제안하였다. 먼저, 각각의 마이크로파 링크 경로 길이에 해당하는 강우에 의한 엑스밴드 레이더의 평균 감쇠 크기(

,

,

,

,

,

,

)를 엑스밴드 레이더 주파수로 변환한 7개의 마이크로파 링크 감쇠(

)와 링크 길이에 해당하는 엑스밴드 레이더 반사도(

)를 이용하여 계산하였고, 각각의 비용함수(

)가 최소(=0.25)가 될 때의 감쇠 보정 계수(

1,

2,

3,

4,

5,

6,

7)를 각각 산출하였다. 시공간적으로 변동성이 적은 층상운 강우 사례에서는 7개의 감쇠 보정 계수들의 평균값을 사용하였고, 대류운 사례에서는 7개의 감쇠 보정 계수들의 최대값을 최적의 감쇠 보정 계수로 결정하였다. 본 발명에서는 강우의 시공간적인 변동을 고려할 수 있는 최적의 감쇠 보정 계수를 결정할 수 있고, 특정 마이크로파 링크가 기계적인 원인으로 감쇠 자료를 제공할 수 없을 때에도 안정적으로 감쇠 보정 계수를 계산할 수 있는 장점이 있다.In the present invention, the optimal X-band radar attenuation correction coefficient considering the temporal and spatial variability of rainfall

To determine , a method using all 7 microwave link attenuation data located within the radar radius is proposed. First, the average attenuation of the X-band radar by rainfall corresponding to each microwave link path length (

,

,

,

,

,

,

) to the X-band radar frequency attenuating the seven microwave links (

) and the X-band radar reflectivity corresponding to the link length (

), and each cost function (

) becomes the minimum (=0.25) attenuation correction factor (

One,

2,

3,

4,

5,

6,

7) were calculated respectively. In the case of stratiform rainfall with little temporal and spatial variability, the average value of 7 attenuation correction coefficients was used, and in the case of convective cloud, the maximum value of the 7 attenuation correction coefficients was determined as the optimal attenuation correction coefficient. In the present invention, it is possible to determine the optimal attenuation correction coefficient that can consider the temporal and spatial fluctuations of rainfall, and to stably calculate the attenuation correction coefficient even when a specific microwave link cannot provide attenuation data due to mechanical reasons. .

Next, a method for correcting X-band dual polarization radar reflectivity using microwaves of a multi-terrestrial communication base station according to the present invention will be described with reference to the drawings. Each step of the X-band dual polarization radar reflectivity correction method using microwaves of a multi-terrestrial communication base station according to the present invention, which will be described later, uses the above-described X-band dual polarization radar reflectivity correction device using microwaves of a multi-terrestrial communication base station.

18 is a flowchart of an X-band dual polarization radar reflectivity correction method using microwaves of a multi-terrestrial communication base station according to the present invention.

Referring to FIG. 18, the X-band dual polarization radar reflectivity correction method using microwaves of a multi-terrestrial communication base station according to the present invention includes collecting observation data (S1, not shown), and determining whether or not there is rainfall based on microwave attenuation data. A step of detecting (S2, not shown), and a step of correcting the reflectivity of the X-band radar (S3).

In the step of collecting observation data (S1), the observation data collection module collects observation data for X-band radar reflectivity correction. Here, the observation data collected in the step of collecting the observation data (S1) is the transmission power and reception power of the microwave link, recorded in the rainfall detector of the Automatic Weather System (AWS) of the Korea Meteorological Administration installed around the microwave link. It includes the rainfall time and cumulative rainfall and rainfall time data recorded in the rain gage, the reflectivity of the X-band radar, and the reflectivity of the S-band radar.

In step S2 of detecting whether or not there is rain based on the microwave attenuation data, the rain presence detection module detects whether or not there is rain based on the microwave attenuation data.

와 감쇠 보정 계수

, b를 적용하여 계산한 게이트(r)별 엑스밴드 레이더 감쇠 크기

로 감쇠 보정한 레이더 반사도

를 산출하여 엑스밴드 레이더 반사도를 보정한다. 이러한 엑스밴드 레이더의 반사도를 보정하는 단계(S3)는 비용함수를 판단하는 단계(S3-1)와, 레이더 반사도

를 산출하여 엑스밴드 레이더 반사도를 보정하는 단계(S3-2)를 포함한다.In the step of correcting the reflectivity of the X-band radar (S3), the cost function is determined to calculate the attenuation correction coefficient, and the radar reflectivity

and the attenuation correction factor

X-band radar attenuation for each gate (r) calculated by applying , b

Attenuation-corrected radar reflectivity with

Calculate and correct the X-band radar reflectivity. The step of correcting the reflectivity of the X-band radar (S3) includes the step of determining the cost function (S3-1), the radar reflectivity

Compensating the X-band radar reflectivity by calculating (S3-2).

In the step of determining the cost function (S3-1), the cost function is calculated based on the observation data collected in the step of collecting observation data (S1), and it is determined whether the calculated cost function is minimum. To this end, the step of determining the cost function (S3-1) includes the step of calculating the attenuation size for each X-band radar gate (S3-1-1) and calculating the microwave attenuation caused by the rain using the link characteristics. Step (S3-1-2), calculating microwave attenuation (S3-1-3), calculating X-band radar average attenuation (S3-1-4), and calculating a cost function ( S3-1-5).

)를 연산한다. 여기서, 엑스밴드 레이더 게이트(r) 별 감쇠 크기(

)는 전술된 수학식 7과 같다.In the step of calculating the attenuation size for each X-band radar gate (S3-1-1), the attenuation size calculation module for each X-band radar gate determines the attenuation size for each X-band radar gate r (

) is computed. Here, the attenuation size for each X-band radar gate (r) (

) is the same as Equation 7 described above.

)를 산출한다.In step S3-1-2 of calculating the microwave attenuation caused by rainfall using the link characteristics, the microwave attenuation calculation module uses the difference between the transmission power and the reception power of the microwave link to calculate the microwave attenuation (rainfall-caused attenuation,

) is calculated.

)를 산출한다. 이는 전술된 수학식 9와 같이 구할 수 있다.In the step of calculating the microwave attenuation size (S3-1-3), the microwave attenuation size calculation module converts the microwave attenuation size to the radar frequency (

) is calculated. This can be obtained as in Equation 9 above.

)를 계산한다.In the step of calculating the X-band radar average attenuation size (S3-1-4), the X-band radar average attenuation size calculation module corresponds to the microwave link path length as shown in Equation 8 above (

) is calculated.

)와 변환된 마이크로파 감쇠 크기(

)간의 차이를 계산하여 전술된 수학식 10과 같이 비용함수(

)를 추정한다.In the step of calculating the cost function (S3-1-4), the average attenuation size of the X-band radar (

) and the converted microwave attenuation magnitude (

) by calculating the difference between the cost function (as shown in Equation 10 above)

) is estimated.

를 산출하여 엑스밴드 레이더 반사도를 보정하는 단계(S3-2)는 레이더 반사도

를 산출하여 엑스밴드 레이더 반사도를 보정한다. 이를 위해서, 레이더 반사도

를 산출하여 엑스밴드 레이더 반사도를 보정하는 단계(S3-2)는 감쇠 보정 계수를 연산하는 단계(S3-2-1)와, 감쇠 보정 계수를 선택하는 단계(S3-2-2), 및 반사도를 보정하는 단계(S3-2-3)를 포함한다.radar reflectivity

The step of correcting the X-band radar reflectivity by calculating (S3-2) is the radar reflectivity

Calculate and correct the X-band radar reflectivity. For this purpose, the radar reflectivity

Compensating the X-band radar reflectivity by calculating (S3-2) includes calculating an attenuation correction coefficient (S3-2-1), selecting an attenuation correction coefficient (S3-2-2), and reflectivity. and a step of correcting (S3-2-3).

The step of calculating the attenuation correction coefficient (S3-2-1) is the microwave link attenuation obtained by converting the average attenuation of seven X-band radars by rainfall corresponding to the microwave link path length into seven X-band radar frequencies and each Calculate the damping correction coefficient when the cost function becomes the minimum. Of course, in this embodiment, since the characteristics of seven microwave links are input to the observation data collection module, the average attenuation of seven X-band radars is exemplified, and this will vary depending on the number of characteristics of microwave links input to the observation data collection module. can

In the step of selecting the attenuation correction coefficient (S3-2-2), among the attenuation correction coefficients calculated in the step of calculating the attenuation correction coefficient (S3-2-1), in the case of stratiform rainfall with little temporal and spatial variability, seven attenuations are selected. The average value of the correction coefficients is selected, and in the case of convective clouds, the maximum value of the seven attenuation correction coefficients is selected as the optimal attenuation correction coefficient.

와 감쇠 보정 계수

, b를 적용하여 계산한 게이트(r)별 엑스밴드 레이더 감쇠 크기

를 이용하여, 전술된 수학식 11과 같이 감쇠 보정한 레이더 반사도

를 산출하여 엑스밴드 레이더 반사도를 보정한다.In the step of correcting the reflectivity (S3-2-3), the X-band radar reflectivity correction module adjusts the radar reflectivity

and the attenuation correction factor

X-band radar attenuation for each gate (r) calculated by applying , b

Using Equation 11, the attenuation-corrected radar reflectivity

Calculate and correct the X-band radar reflectivity.

As described above, the present invention has been described with reference to the drawings illustrated, but the present invention is not limited by the embodiments and drawings disclosed in this specification, and various modifications are made by those skilled in the art within the scope of the technical idea of the present invention. It is obvious that variations can be made. In addition, although the operational effects according to the configuration of the present invention have not been explicitly described and described while describing the embodiments of the present invention, it is natural that the effects predictable by the corresponding configuration should also be recognized. That is, the present invention may be applied to various situations other than the medical request situation described above, for example, area search, map service, base data construction of a specific area, and the like. In addition, the above-described control method may be implemented as a program and stored in a storage medium.

100: observation data collection module
200: microwave attenuation calculation module
300: rain presence detection module
310: window size calculation module
320 Average microwave attenuation calculation module
330: test statistic calculation module of microwave attenuation
340: threshold value calculation module
350: primary rain presence detection module
360: microwave reference attenuation calculation module
370: secondary rain presence detection module
400: reflectivity correction module
410: microwave attenuation determination module
420: attenuation size calculation module for each X-band radar gate
430: X-band radar average attenuation magnitude calculation module
440: microwave attenuation size calculation module
450: cost function calculation module
460: X-band radar reflectivity correction module

Claims (4)

The transmission power and reception power of the microwave link are collected, and recorded at regular intervals in the rain detector and rain gauge of at least one Automatic Weather System (AWS) installed around the microwave link. An observation data collection module for collecting cumulative rainfall data and rainfall time data;
A microwave attenuation calculation module for calculating microwave attenuation using a difference between transmit power and received power of the microwave link;
A rain presence detection module for detecting whether or not there is rain based on the autocorrelation coefficient of the microwave attenuation, and
Attenuation size for each X-band radar gate (r) when rain is detected by the rain presence detection module (

) and the radar reflectivity of the X-band radar (

) attenuation-corrected radar reflectivity calculated using

) X-band dual polarization radar reflectivity correction device using multi-terrestrial communication base station microwaves including a reflectivity correction module having an X-band radar reflectivity correction module for correcting X-band radar reflectivity with ).

According to claim 1,
The attenuation corrected radar reflectivity (

)Is,

is,
remind

is the magnitude of the X-band radar attenuation,

ego,

,

,
remind

X-band dual polarization radar reflectivity correction device using multi-terrestrial communication base station microwaves, where b is the attenuation correction coefficient of X-band radar.
An observation data collection module collects transmission power and reception power of a microwave link, and transmits power to a rain detector and a rain gauge of at least one Automatic Weather System (AWS) installed around the microwave link. Collecting accumulated rainfall data and rainfall time data recorded at regular intervals;
Calculating, by a microwave attenuation calculation module, microwave attenuation using a difference between transmit power and received power of the microwave link;
Detecting presence or absence of rain by a rain presence detection module based on the autocorrelation coefficient of the microwave attenuation; and
The reflectivity correction module determines the cost function to calculate the attenuation correction coefficient, and the radar reflectivity

and the attenuation correction factor

X-band radar attenuation for each gate (r) calculated by applying , b

Attenuation-corrected radar reflectivity with

A method for correcting X-band dual polarization radar reflectivity using multi-terrestrial communication base station microwaves, comprising calculating and correcting X-band radar reflectivity.
According to claim 3,
The attenuation corrected radar reflectivity (

)Is,

is,
remind

is the magnitude of the X-band radar attenuation,

ego,

,

,
remind

X-band dual polarization radar reflectivity correction method using multi-terrestrial communication base station microwaves, where b is the attenuation correction coefficient of X-band radar.

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