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ISSN : 1225-6692(Print)
ISSN : 2287-4518(Online)
Journal of the Korean earth science society Vol.34 No.1 pp.1-12
DOI : https://doi.org/10.5467/JKESS.2013.34.1.1

X-밴드 이중편파레이더에서 관측된 채프에코의 특성

서은경1,*·박소라1·남경엽2·허솔잎2
1공주대학교 지구과학교육과, 314-701, 충청남도 공주시 공주대학로 56
2국립기상연구소 응용기상연구과, 156-720, 서울특별시 동작구 여의대방로 16길 61
채프에코는 기상레이더 영상에서 강수에코로 자주 오인된다. 본 연구에서는 채프에코를 효과적으로 제거하기 위하여 국립기상연구소 X밴드 이중편파레이더에서 관측한 자료를 활용하여 채프에코의 반사도와 각각의 이중편파변수의 관계성을 분석하였다. 특히 본 연구는 채프에코 사례의 입체관측자료 영상에서 채프에코가 발생한 영역만을 선별하여 이중편파변수 자료들을 수집하였다. 전반적으로 이중편파변수(반사도, 차등반사도, 교차상관계수, 차등반사도 표준편차와 비차등위상차)에 대해 채프에코의 변수 값이 강수에코보다 넓은 범위를 차지하며, 채프 섬유의 공간적 배치는 레이더빔에 대해 수평적으로 놓여있는 경향이 나타났다. 일부 강수에코의 교차상관계수는 0.8 이하의 값을 갖고 있기 때문에 채프에코 값과 상당한 중첩이 나타났다. 일반적으로 교차상관계수는 강수에코와 채프에코를 효과적으로 분리하는데 좋은 변수로 고려되고 있지만, 이 연구는 교차상관계수만을 이용하여 채프에코를 제거할 경우에 일부 강수에코가 제거될 가능성이 있음을 시사한다.

Characteristics of Chaff Echoes Observed by X-band Dual Polarization Radar

*Corresponding author: ekseo@kongju.ac.kr

Tel: +82 41 850 8293

Fax: +82 41 850 8299
, Eun-Kyoung Seo1,*, Sora Park1, Kyung-Yeub Nam2, and Sol-Ip Heo2

1Department of Earth Science Education, Kongju National University, Chungnam 314-701, Korea
2Applied Meteorology Research Laboratory, National Institute of Meteorological Research,
Seoul 156-720, Korea

Abstract

To effectively remove chaff echoes, which are often misidentified as precipitation echoes on weather radars, thisstudy examines the relationship between the radar reflectivity and each of dual polarimetric parameters. The dualpolarimetric parameters are collected only for the echo areas identified as chaff echoes on the NIMR X band dualpolarization radar. Overall, the polarimetric parameters (i.e., reflectivity, differential reflectivity, cross correlation coefficient,standard deviation of differential reflectivity and specific differential phase) for chaff echoes have a wider range of valuesthan those for precipitation echoes and the chaff filaments tend to be horizontally oriented to radar beams. There appearsto be a considerable overlap in the cross correlation coefficient range of chaff and precipitation echoes since someprecipitation echoes have cross correlation coefficient lower than 0.8. Therefore, although the cross correlation coefficientis known to be a good variable in identifying and separating chaff echoes from precipitation echoes, it is suggested thatadditional care should be taken when using the cross correlation coefficient solely in removing chaff echoes.

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