Journal of the Korean earth science society (한국지구과학회지)

The Korean Earth Science Society (한국지구과학회)
권호 표지
DOI QR코드

DOI QR Code

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

X-밴드 이중편파레이더에서 관측된 채프에코의 특성

  • Seo, Eun-Kyoung (Department of Earth Science Education, Kongju National University) ;
  • Park, Sora (Department of Earth Science Education, Kongju National University) ;
  • Nam, Kyung-Yeub (Applied Meteorology Research Laboratory, National Institute of Meteorological Research) ;
  • Heo, Sol-Ip (Applied Meteorology Research Laboratory, National Institute of Meteorological Research)
  • 서은경 (공주대학교 지구과학교육과) ;
  • 박소라 (공주대학교 지구과학교육과) ;
  • 남경엽 (국립기상연구소 응용기상연구과) ;
  • 허솔잎 (국립기상연구소 응용기상연구과)
  • Received : 2012.10.09
  • Accepted : 2012.12.20
  • Published : 2013.02.28
Download PDF
⟨ Previous Next ⟩

Abstract

To effectively remove chaff echoes, which are often misidentified as precipitation echoes on weather radars, this study examines the relationship between the radar reflectivity and each of dual polarimetric parameters. The dual polarimetric parameters are collected only for the echo areas identified as chaff echoes on the NIMR X-band dual polarization 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 values than those for precipitation echoes and the chaff filaments tend to be horizontally oriented to radar beams. There appears to be a considerable overlap in the cross correlation coefficient range of chaff and precipitation echoes since some precipitation echoes have cross correlation coefficient lower than 0.8. Therefore, although the cross correlation coefficient is known to be a good variable in identifying and separating chaff echoes from precipitation echoes, it is suggested that additional care should be taken when using the cross correlation coefficient solely in removing chaff echoes.

채프에코는 기상레이더 영상에서 강수에코로 자주 오인된다. 본 연구에서는 채프에코를 효과적으로 제거하기 위하여 국립기상연구소 X-밴드 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.

Keywords

References

  1. Anderson, A.D. and Hoehne, W.E., 1956, Experiments using window to measure high altitude winds. Bulletin of American Meteorology Society, 37, 454-457.
  2. Balakrishnan, N. and Zrnic, D.S., 1990, Use of polarization to characterize precipitation and discriminate large hail. Journal of Atmospheric Sciences, 47, 1525-1540. https://doi.org/10.1175/1520-0469(1990)047<1525:UOPTCP>2.0.CO;2
  3. Brandt, M.B. and Atkin, D.V., 1998, Chaff in the vicinity of thunderstorms in Southern California on 6 June 1997. NWS Western Region Technical Attachments, 98, Available online at http://www.wrh.noaa.gov/wrh/98TAs/9804/index.html (November 5th 2012).
  4. Doviak, R.J. and Zrnic, D.S., 1993, Doppler radar and weather observations. Academic Press, New York, USA, 562 p.
  5. Garbacz, R.J., Cable, V., Wickliff, R., Caldecott, R., Buk, J., Lam, D., Demarest, K., and Yee, A., 1975, Advanced radar reflector studies. The Ohio State University Electro Science Laboratory, Department of Electrical Engineering; prepared under Contract F33615-72-C-1435 for Aeronautical Systems Division, Wright-Patterson Air Force Base, Ohio (AFAL-TR-75-219).
  6. Gorgucci, E.D., Scarchilli, G., and Chandrasekar, V., 1999, A procedure to calibrate multiparameter weather radar data using the properties of the rain medium. IEEE Transactions on Geoscience and Remote Sensing, 37, 269-276. https://doi.org/10.1109/36.739161
  7. Han, H.-Y., Heo, B.-H., Kim, W.G., You, C.-H., Gu, J.-Y., and Lee, J.-H., 2010, Chaff echo identification and removal algorithm. Proceeding of the Autumn meeting of KMS 2010, p. 262-263. (in Korean)
  8. Han, H.-Y., Heo, B.-H., Jung, S.-H., Lee, G.W., You, C.-H., and Lee, J.-H., 2011, Elimination of chaff echoes in reflectivity composite from an operational weather radar network using infrared satellite data. Atmosphere, 21, 285-301. (in Korean)
  9. Illingworth, A.J. and Caylor, I.J., 1989, Cross polar observations of the bright band. Preprints, 24th Conference on Radar Meteorology, Tallahassee, American Meteorological Society, 323-327.
  10. Jessup, E.A., 1972, Interpretations of chaff trajectories near a severe thunderstorm. Monthly Weather Review, 100, 653-661. https://doi.org/10.1175/1520-0493(1972)100<0653:IOCTNA>2.3.CO;2
  11. Jung, S.-H., Lee, G.W., Kim, H.-W., and Kuk, B.J., 2011, Development of convective cell identification and tracking algorithm using 3-dimensional radar reflectivity fields. Atmosphere, 21, 243-256. (in Korean)
  12. Kim, D.S., Lee, D.I., Kim, P.K., and Rinehart, R.E., 2006, An experiment of chaff diffusion in clear sky using a WSR-88D radar. Journal of Korean Meteorological Society, 42, 225-236.
  13. Lee, D.I., 2000, A WSR-88D radar observation of chaff transport and diffusion in clear sky. Bulletin of Korean Environmental Sciences Society, 4, 263-271.
  14. Maddox, R.A., Howard, K.W., and Dempsey, C.L., 1997, Intense convective storms with little or no lightning over central Arizona: A case of inadvertent weather modification? Journal of Applied Meteorology, 36, 302-314. https://doi.org/10.1175/1520-0450(1997)036<0302:ICSWLO>2.0.CO;2
  15. Martner, B., Marwitz, J.D., and Kropfli, R.A., 1992, Radar observations of transport and diffusion in clouds and precipitation using TRACIR. Journal of Atmospheric and Oceanic Technology, 9, 226-241. https://doi.org/10.1175/1520-0426(1992)009<0226:ROOTAD>2.0.CO;2
  16. Nam, K.-Y., Jang, K.H., Choi, Y.J., and Ryu, S.B., 2010, Analysis of chaff echoes using dual polarimetric radar. Proceedings of the Autumn meeting of KMS 2010, p. 416-417. (in Korean)
  17. National Institute of Meteorological Research (NIMR), 2010, Research for the meteorological observation technology and its application (II). 308 p. (in Korean)
  18. Rinehart, R.E., 2010, Radar for meteorologists. Rinehart Publications, Nevada Missouri, USA, 482 p.
  19. Vasiloff, S. and Struthwolf, M., 1997, Chaff mixed with radar weather echoes. NWS Western Region Technical Attachment, 97-02, 10 p.
  20. Vasiloff, S., 2002, Chaff and the WSR-88D precipitation processing system. NWS Western Region Technical Attachment, 02-09, Available online at http://www.wrh.noaa.gov/wrh/02TAs/0209/ (November 11th 2012).
  21. Warner, J. and Bowen, E.G., 1953, A new method of studying the fine structure of air movements in the free atmosphere. Tellus, 5, 36-41. https://doi.org/10.1111/j.2153-3490.1953.tb01034.x
  22. Ziegler, C.L., Rasmussen, E.N., Shepherd, T.R., Watson, A.I., and Straka, J.M., 2001, Evolution of low-level rotation in the 29 May 1994 Newcastle-Graham, Texas, storm complex during VORTEX. Monthly Weather Review, 129, 1339-1368. https://doi.org/10.1175/1520-0493(2001)129<1339:TEOLLR>2.0.CO;2
  23. Zrnic, D.S. and Ryzhkov, A.V., 1999, Polarimetry for weather surveillance radar. Bulletin of American Meteorology Society, 80, 389-406. https://doi.org/10.1175/1520-0477(1999)080<0389:PFWSR>2.0.CO;2
  24. Zrnic, D.S. and Ryzhkov, A.V., 2004, Polarimetric properties of chaff. Journal of Atmospheric and Oceanic Technology, 21, 1017-1024. https://doi.org/10.1175/1520-0426(2004)021<1017:PPOC>2.0.CO;2