KR20130027104A - Method for elimination of chaff echoes in reflectivity composite from an operational weather radar network using infrared satellite data - Google Patents

Abstract

PURPOSE: A chaff echo removal method of operational meteorological radar reflectivity composite using satellite infrared image data is provided to manage radar observation data and to offer a very accurate short term meteorological forecast. CONSTITUTION: Brightness temperature color index data of a satellite infrared image is collected in real time in a plurality of radar observation networks and a meteorological satellite(S201,S202). A radar reflectivity composite image is generated from the collected radar observation data(S203) and resolution of the radar reflectivity composite image is converted to the same as the satellite infrared image(S204). To coincide the satellite infrared image with the central coordinate of the radar reflectivity composite image, the central point is converted(S205). Only the satellite infrared image in the observation range of the radar is stored, the satellite infrared image out of the observation range of the radar is processed as a null, and the satellite infrared image is converted to coincide with the radar observation radius(S206). The value of the radar reflectivity composite image corresponding to the grid point having a smaller color index than the brightness temperature color index threshold of the satellite infrared image is removed from the radar reflectivity composite image(S209). The radar reflectivity composite image, from which a chaff echo is removed, is generated(S210). [Reference numerals] (AA) Start; (BB) End; (S201) Collecting radar observation data in real time; (S202) Collecting brightness temperature(T_B) color index data of a satellite infrared image in real time; (S203) Generating a radar reflectivity composite image; (S204) Converting the resolution of the radar reflectivity composite image; (S205) Coinciding the central lattice point of the satellite infrared image with the radar reflectivity composite image; (S206) Coinciding the satellite infrared image with the observation range of the radar reflectivity composite image; (S207) Comparing brightness temperature color index data of a satellite infrared image in the most adjacent time zone to the converted radar reflectivity composite image; (S208) T_B color index of a predetermined lattice point in the satellite infrared image < T_B color index ?; (S209) Removing a lattice point with a color index value smaller than a critical brightness temperature(T_B) color index value from the radar reflectivity composite image; (S210) Generating a radar reflectivity composite image from which a chaff echo is removed

Description

Method for elimination of chaff echoes in reflectivity composite from an operational weather radar network using infrared satellite data}

The present invention relates to a chap echo removal method, and more particularly, chap echo is automatically determined by comparing and analyzing radar observation data and satellite observation data using the fact that chap is observed as an echo on the radar but not on the satellite. The present invention relates to a method for chaff echo removal of commercial weather radar reflectance composite data using satellite infrared image data that can be identified and removed.

Weather radars, which provide data of high temporal and spatial resolution in large areas, are essential for live surveillance and forecasting of local dangerous weather that develop rapidly in a short time. However, radar data includes topographical echoes, topographical echoes, anomalous propagation echoes, and chaff echoes, and so on. Therefore, it is difficult to use raw radar data directly for forecasting.

Among the non-echo-echo echoes, Chap Eco is an echo of radar waves scattered in small metal chaffs that military aircraft sprayed into the atmosphere to avoid detection from enemy radars. In radar reflectivity images, chaff echoes are similar to precipitation echoes and move along the wind, making it difficult for experienced forecasters to distinguish them from rainfall echoes. In particular, chaff echoes with strong reflectivity are identified as convective cells in the convective cell discrimination algorithm. Therefore, in order to quantitatively use the weather radar data and to improve the usability in the forecasting service, chaff echo should be removed.

Accordingly, an object of the present invention is to provide a method for analyzing chaff echo generation characteristics and automatically identifying and removing chaff echo from commercial weather radar reflectivity composite data.

Through this, the present invention can contribute to providing more accurate ultra-short weather forecast as well as quality control of radar observation data.

An embodiment of the present invention for achieving the above object, the threshold value for the luminance temperature color index of the satellite infrared image by comparing the radar reflectivity composite data measured at predetermined time intervals and the satellite infrared image measured at a similar time zone Calculating; Converting the radar reflectance composite image and the satellite infrared image collected in real time into the same data format; Comparing the luminance temperature color index of the converted satellite infrared image with a threshold of the calculated luminance temperature color index of the satellite infrared image; And removing a radar reflectance composite image value corresponding to a grid point having a color index value smaller than a threshold value of the luminance temperature color index of the calculated satellite infrared image from the converted radar reflectivity composite image. The method includes chaff echo removal method of commercial weather radar reflectivity composite data using satellite infrared images.

At this time, the step of calculating the threshold value for the luminance temperature color index of the satellite infrared image, comparing the radar reflectance composite image and the satellite infrared image, the luminance temperature value of the grid point determined to be a clear area in the satellite infrared image luminance temperature Determining the color index threshold of the; may be made.

The converting radar reflectivity composite image may include: synthesizing data collected from 11 weather radar to generate a radar reflectivity composite image; And converting the generated radar reflectivity of the synthesized image to match the resolution of the satellite infrared image.

The converting of the satellite infrared image may include: reading a satellite infrared image having a predetermined resolution from observation data collected from a meteorological satellite; Converting a center coordinate point of the read satellite infrared image to coincide with a radar coordinate transformation center point; And rearranging the converted satellite infrared image with respect to the radar observation area.

According to the present invention, the chapel echo can be automatically identified and removed from the commercial weather radar reflectivity composite image using the satellite infrared image, thereby contributing to providing more accurate short-term weather forecast as well as quality control of radar observation data.

In addition, according to the present invention, the real-time weather radar reflection can also be automatically identified and removed from the composite image using satellite infrared images, and accurate radar precipitation estimation can be performed without the error that the chaff is mistaken for precipitation.

1 is a block diagram showing the overall configuration of a radar quality control system including a chap echo removal apparatus using a satellite infrared image according to an embodiment of the present invention.
FIG. 2 is a flowchart illustrating a method of identifying and removing chaff echo in the chaff echo removing apparatus using the satellite infrared image shown in FIG. 1.
3 is an exemplary view showing a radar observation network and an observation radius used in the present invention.
4 is an exemplary view showing a radar reflectivity composite image for explaining the characteristics of the chaff echo in general.
FIG. 5 is an exemplary view showing a vertical cross-sectional image of the chap echo region shown by a red straight line in FIG. 4.
FIG. 6 is an exemplary view showing a resultant image of a first example of actually applying a chap echo removal method using a satellite infrared image according to an embodiment of the present invention.
FIG. 7 is an exemplary view illustrating a resultant image of a second example in which a chap echo removal method using satellite infrared images according to an embodiment of the present invention is actually applied.
FIG. 8 is an exemplary view illustrating a resultant image of a third example of actually applying a chap echo removal method using a satellite infrared image according to an embodiment of the present invention.
FIG. 9 is an exemplary view illustrating a resultant image of a fourth case of actually applying a chap echo removal method using a satellite infrared image according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Further, in order to clearly illustrate the present invention in the drawings, portions not related to the description are omitted. In addition, the same code | symbol is attached | subjected about the similar part throughout the specification. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

1 is a block diagram showing the overall configuration of a radar quality control system including a chap echo removal apparatus using a satellite infrared image according to an embodiment of the present invention.

As shown in FIG. 1, the chaff echo removing apparatus 10 collects and stores the weather radar observation data 20 and the satellite infrared image observation data 30 in real time. That is, the chaff echo removing apparatus 10 collects weather radar observation data generated by performing a three-dimensional observation of the atmosphere every 10 minutes in the weather radar observation network, and also generates a satellite radar observation every 30 minutes. Collects infrared image observation data in real time.

The chaff echo removing apparatus 10 generates a radar reflectance composite image from the collected weather radar observation data, and then converts the resolution of the generated radar reflectivity composite image to be the same as that of the satellite infrared image. In addition, the chaff echo removal apparatus 10 generates three-dimensional radar data so that the user can perform a vertical cross-sectional function for a desired point by using the generated radar reflectivity composite image.

In addition, the chaff echo removal apparatus 10 converts the center point according to the center coordinate point of the radar reflectance composite image, and stores only the satellite infrared image within the radar observation radius, and the data outside the radar observation radius is null. Treat it as a (null) value. As a result, the satellite IR image and the radar reflection field have the same format.

In addition, the chaff echo removing apparatus 10 sets a threshold value of the luminance temperature color index so as to distinguish between a clear region and a cloud region using a satellite infrared image. Specifically, the chaff echo removing apparatus 10 compares the radar reflectivity composite image with the satellite infrared image data so that the cloud is removed from the luminance temperature distribution of the satellite infrared image so that only the chap echo can be removed without removing the precipitation echo from the radar image. The luminance temperature value of the lattice point determined to be an unclear region is determined as a threshold of the luminance temperature color index. At this time, the threshold of the luminance temperature color index may be empirically determined by the administrator.

In addition, the chafe echo removal apparatus 10 compares the radar reflectance composite image and the satellite infrared image generated from the collected observation data in real time, and the luminance temperature color of the satellite infrared image whose luminance temperature value is calculated in advance in the radar reflectance composite image. The radar reflectivity corresponding to the lattice point below the exponential threshold is removed.

As such, the chaff echo removing apparatus 10 removes the chaff echo displayed on the radar reflectivity composite image by comparing the radar reflectivity composite image and the satellite infrared image.

Meanwhile, in the present embodiment, the chaff echo removing apparatus 10 is illustrated and described as being included in the radar quality management system 1, but may be configured as a separate system or a server.

FIG. 2 is a flowchart illustrating a method of identifying and removing chaff echo in the chaff echo removing apparatus using the satellite infrared image shown in FIG. 1.

As shown in FIG. 2, first, the radar observation data generated by observation in a plurality of radar observation networks and the luminance temperature color index data of satellite infrared images generated by observation of atmospheric phenomenon in a meteorological satellite are respectively collected in real time. (S201, S202).

Then, in order to compare the radar observation data collected in real time and satellite infrared image data, a radar reflectance composite image is generated from the collected radar observation data (S203), and the resolution of the radar reflectance composite image is the same as that of the satellite infrared image. It converts (S204).

Subsequently, after converting the center point to match the collected satellite infrared image according to the center coordinate point of the radar reflectance composite image (S205), only the satellite infrared image within the radar observation radius is stored, and the satellite infrared image outside the radar observation radius is By processing as a null value, the satellite infrared image is converted to match the radar observation radius of the radar reflectivity composite image (S206).

Next, the luminance temperature color index data of the satellite infrared image observed in the closest time zone are compared with the observed time of the converted radar reflectivity composite image (S207). In other words, observation data are collected every 10 minutes for radar reflectivity composite images, and observation data are collected every 30 minutes for satellite infrared images.

As a result of the comparison, if a lattice point having a color index value smaller than the luminance temperature color index threshold of the satellite infrared image is present in the satellite infrared image (S208), the grid has a color index value smaller than the luminance temperature color index threshold of the satellite infrared image. The value of the radar reflectance composite image corresponding to the point is removed from the radar reflectivity composite image (S209).

Thereafter, the radar reflectance from which the chap echo is removed is generated (S210).

3 is an exemplary view showing a radar observation network and an observation radius used in the present invention.

As shown in FIG. 3, there are 11 radar observation networks (red circle) currently operated by the Korea Meteorological Agency, Baeknyeongdo, Myeonbongsan, and Incheon Yeongjongdo are C-bands, and the remaining eight radars are S-bands. The light gray area corresponds to the area observed on the radar, and this radar network generates observation data every 10 minutes in real time.

4 is an exemplary view showing a radar reflectance composite image for explaining the characteristics of the chaff echo in general, a representative example of the chaep echo on May 13, 2010, (a) is a radar reflectivity composite image around 9:40, (b) a radar reflectance composite image around 10 o'clock, (c) a radar reflectivity composite image around 10:30, (d) a radar reflectivity composite image around 11 o'clock, (e) a radar reflectance composite image around 12 o'clock, (f) shows a radar reflectivity synthesized image at about 13 o'clock, (g) shows a radar reflectivity synthesized image at around 14 o'clock, and (h) shows a radar reflectivity synthesized image around 15 o'clock.

As shown in (a) to (h) of FIG. 4, when the chaff is sown at about 9:40, it looks like a convection cell, and gradually, as time passes, the chaff echo narrows horizontally along the wind direction. As it spreads for a long time, the echo intensity gradually decreases. The horizontal distance of Chap Eco was about 65km around 10:30, about 75km around 11, about 115km around about 12, about 140km around about 13, and about 215km around about 14, and the maximum duration was over 5 hours. After the occurrence, it can be seen that the point of strong echo flows along the wind direction with time.

FIG. 5 is an exemplary view showing a vertical cross-sectional image of a chap echo region shown by a red straight line in FIG. 4, (a) is a vertical cross-sectional image of a chap echo region at about 9:40, and (b) is a chaff echo at about 10 hours. Vertical cross-section image of the area, (c) Vertical cross-section image of the chaff echo area around 10:30, (d) Vertical cross-section image of the chaff echo area around 11 o'clock, (e) Vertical cross-section image of the chaff echo area around 12 o'clock The cross-sectional image (f) shows a vertical cross-sectional image of the chaff echo region around 13 o'clock, (g) shows a vertical cross-sectional image of the chaff echo region around 14 o'clock, and (h) shows a vertical cross-sectional image of the chaff echo region around 15 o'clock.

As shown in Fig. 5 (a) to (h), the echo appears in the air between about 3 ~ 8km, the wind direction is from left to right direction, the echo with strong intensity of 40dBZ or more reflectivity over time is the wind direction The altitude was lowered and the strength gradually weakened. As such, Chap Eco moves in the wind direction and has a velocity value according to the movement. In the vertical section image, Chap Eco is similar to Precipitation Eco, so it is difficult to distinguish it from Precipitation Eco.

Hereinafter, a case in which the chap echo removal method according to the present embodiment is applied to an actual case will be described with reference to FIGS. 6 to 9. Here, the case period of applying and verifying the Chap Eco removal method is from May 1, 2010 to June 15, 2010.

In addition, in the chaff echo removal method according to the present invention, the map projection method of the radar composite file of 2 km lattice spacing is Lambert Conic Conformal map projection, above the reference point, the hardness is 38 ° N, 126 ° E, x of the reference point , y coordinate is (230, 462). Satellite infrared images use observation data generated every 30 minutes except 00, 06, 12, and 18 UTC. In addition, it uses the luminance temperature of 1 infrared channel (IR1, 10.3 ~ 11.3㎛), resolution is 2km, consists of 711 × 711 grid, and coordinates of satellite infrared image coinciding with the center point of radar coordinate transformation (230, 462). The point is (110, 520). Here, the luminance temperature of infrared IR1 is composed of color index (0 ~ 255), color index 0 corresponds to absolute temperature 330.1 K, Celsius temperature 56.9 ℃, and color index 255 is absolute temperature 142.6K, -130.6 Celsius temperature. The higher the color index value in ℃, the lower the temperature.

FIG. 6 is an exemplary view showing a resultant image of a first example of actually applying a chap echo removal method using a satellite infrared image according to an embodiment of the present invention. Here, the first case is a case where Chap Eco occurred on a clear day at 16:00 on May 12, 2010.

6 (a) shows a 1.5km-high radar reflectance composite image, (b) shows a radar reflectance composite image after applying the Chap echo removal method, (c) shows a satellite infrared image, and (d) shows a satellite infrared ray Each luminance temperature distribution of the image is shown.

The radar echoes shown in the radar reflectance composite image of FIG. 6 (a) are all chap echoes, and in the satellite composite image at the same time (c), the area corresponding to the chap echo region shown in the radar reflectivity composite image of (a) is cloud It was clear without.

Therefore, as a result of applying the chaff echo removal algorithm using the preset luminance temperature color index threshold, it can be seen that chaff echo near the south coast of Jeollanam-do is removed as shown in FIG.

As described above, the chaff echo removal algorithm developed according to the present embodiment appropriately removes chaff echo in the case where chaff echo appeared on a clear day.

FIG. 7 is an exemplary view illustrating a resultant image of a second example in which a chap echo removal method using satellite infrared images according to an embodiment of the present invention is actually applied. In the second case, at 17 o'clock on June 3, 2010, Chap Eco and Convective Precipitation Eco were simultaneously observed. In the vicinity of Jeollanam-do (area A in FIG. 7A), convective cells developed, and the rainfall of 3.0 mm was recorded for 1 hour on the ground automatic meteorological observation equipment (the rocky point).

Figure 7 (a) is a 1.5km high radar reflectance composite image, (b) is a radar reflectivity composite image after applying the Chap echo removal method, (c) is a satellite infrared image, (d) a satellite infrared Each luminance temperature distribution of the image is shown.

As shown in (a) of FIG. 7, convective precipitation echo appears near Jeollanam-do (area A), and some echoes appearing along the boundary area between Jeolla-do and Gyeongsang-do are shown in FIGS. 7 (c) and (d). According to the satellite image and luminance temperature data, it is judged as weather echo, and the echoes in area B are judged as precipitation echo by convective cells grown to high altitude.

As shown in (b) of FIG. 7, as a result of applying the chaff echo removing algorithm according to the present embodiment, the chaff of the remaining region is not removed while the precipitation echoes of regions A and B of FIG. 7 (a) are not removed. It can be seen that the echoes have been properly removed.

As described above, the chaff echo removal algorithm developed in accordance with the present embodiment appropriately removes the chaff echo even in the case where the chaff echo and the precipitation echo appear simultaneously.

FIG. 8 is an exemplary view showing a resultant image of a third case in which the chaff echo removal method using the satellite infrared image is actually applied. Here, the third case is a case in which convective precipitation echo and chaff echo occurred with a lightning attack on June 15, 2010 at 16:00.

(A) is a composite image of radar reflectivity of 1.5km height, (b) is a composite image of radar reflectivity after applying the present Chap echo removal method, (c) is a satellite infrared image, (d) is a satellite infrared The luminance temperature distributions of the images are respectively shown. Referring to FIG. 8 (a), chaotic echoes appear in the West Sea image (area 2), with an ectopic precipitation phenomenon accompanied by a thunderstorm in various parts of the central region including Gangwon-do (region 1). . In the boundary area between Jeolla-do and Gyeongsang-do (area 3), the developed convective cell echo was observed, and precipitation echoes appeared near Seohan Bay (area 4), and echo-trip echoes were generated near Pyongyang. .

Referring to (c) of FIG. 8, the cloud zones developed in the satellite composite image appear in the interior of Gangwon inland, part of Gyeongsangbuk-do, Gyeonggi-do, and Chungcheong-do, and the cloud zones are highly developed around Jirisan in the border region of Gyeongsang-do and Jeolla-do. There was a developed cloud.

Referring to FIG. 8 (b), the convectiveness of the Naksu Precipitation Eco and Jirisan (Zone 3) accompanied by the epilepsy of Gangwon-do and the central region (Zone 1) as a result of applying the chaff removal algorithm developed in accordance with the present invention. Precipitation Eco, Precipitation Eco near Seohan Bay (area 4) was not removed, and Chape Eco on the West Sea (area 2) was removed.

Even in the case where convective echo and chaff echo appear simultaneously, the chaff echo removal algorithm developed according to the present embodiment appropriately removes chaff echo.

FIG. 9 is an exemplary view showing a resultant image of a fourth case in which the chaff echo removal method using the satellite infrared image is actually applied. In this case, the fourth case is a case in which Chaco echoes and precipitation echoes caused by lower clouds are simultaneously observed at 16:00 on May 26, 2010.

(A) is a composite image of radar reflectivity of 1.5km height, (b) is a composite image of radar reflectivity after applying the present Chap echo removal method, (c) is a satellite infrared image, (d) is a satellite infrared Each luminance temperature distribution of the image is shown.

Referring to FIG. 9 (a), the echoes appearing near Deogyusan (area A) and the south coast area (area B) are Chap Eco which are gradually spreading from 10 o'clock, and the echoes appearing on the east coast (area C) are Precipitation is caused by lower clouds.

Referring to (c) of FIG. 9, although the middle and lower clouds exist in the region A, the radar reflection of FIG. 9 (a) was not shown in the synthesis data, and only Chap Eco was observed.

Referring to FIG. 9B, as a result of applying the chaff echo removal algorithm, the chaff echoes of the lattice points having the middle and lower clouds in the A region are not removed, and the chaff echoes of the clear B region are removed.

So far I looked at the center of the preferred embodiment for the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Accordingly, the disclosed embodiments are to be considered in an illustrative rather than a restrictive sense, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

Further, the apparatus and method according to the present invention can be embodied as computer readable codes on a computer-readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and also include a carrier wave (for example, transmission through the Internet). The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

1. Chap echo removal unit 2. Radar quality management system
10. Radar observation data 20. Satellite infrared image observation data

Claims (5)

Calculating a threshold value for the luminance temperature color index of the satellite infrared image by comparing the radar reflectivity synthesis data measured at predetermined time intervals and the satellite infrared image measured at a similar time zone;
Converting the radar reflectance composite image and the satellite infrared image collected in real time into the same data format;
Comparing the luminance temperature color index of the converted satellite infrared image with a threshold of the calculated luminance temperature color index of the satellite infrared image; And
And removing a radar reflectance composite image value corresponding to a grid point having a color index value smaller than a threshold value of the luminance temperature color index of the calculated satellite infrared image from the converted radar reflectivity composite image. Chap echo removal method of commercial weather radar reflectivity composite data using satellite infrared image.
The method of claim 1,
The calculating of the threshold value of the luminance temperature color index of the satellite infrared image may include comparing the radar reflectance composite image and the satellite infrared image to determine the luminance temperature value of the grid point determined as a clear area in the satellite infrared image. Determining the exponential threshold; chaff echo removal method of the commercial weather radar reflectivity composite data using satellite infrared images, characterized in that consisting of.
The method of claim 1,
The converting the radar reflectivity composite image may include: synthesizing data collected from 11 weather radars to generate a radar reflectivity composite image; And
And converting the resolution of the generated radar reflectivity composite image to match the resolution of the satellite infrared image. Chap echo removal method of the commercial weather radar reflectivity composite data using satellite infrared image, characterized in that the conversion.
The method of claim 1,
The converting of the satellite infrared image may include: reading a satellite infrared image having a predetermined resolution from observation data collected from a meteorological satellite;
Converting a center coordinate point of the read satellite infrared image to coincide with a radar coordinate transformation center point; And
And repositioning the converted satellite infrared image with respect to the radar observation area. The chaff echo removal method of the commercial weather radar reflectivity composite data using the satellite infrared image, comprising:
A recording medium having recorded thereon a program which can be read and executed by a digital signal processing apparatus as a program for performing the method of any one of claims 1 to 4.

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