Ground Subsidence Estimation in a Coastal Reclaimed Land Using JERS-1 L-band SAR Interferometry

JERS-1 L-band SAR Interferometry 를 이용한 연안매립지 지반침하 관측

  • 김상완 (연세대학교 지구시스템과학과) ;
  • 이창욱 (연세대학교 지구시스템과학과) ;
  • 원중선 (연세대학교 지구시스템과학과)
  • Published : 2002.10.01

Abstract

We measured subsidences occurred in a coastal reclaimed land, Noksan industrial complex, from May 2, 1996 to February 21, 1998, using 5 interferograms of JERS-1 L-band SAR. SAR with a spatial resolution of about 16 m can detect the two-dimensional distribution of subsidence that is difficult to be estimated from in situ measurements. Accuracy of the subsidences estimated by 2-pass DInSAR was evaluated using the measurements of Magnetic Probe Extensometer (accuracy of :${\pm}$1 mm) installed at 42 stations. DInSAR measurements were well correlated with the field measurements showing an average correlation coefficient of 0.77. The correlation coefficient was further improved to be 0.87 (with RMSE of 1.44 cm) when only highly coherenced (>0.5) pixels were used. The slope of regression line was 1.04, very close to the unit value. In short, DInSAR measurements have a good linear relation with field measurements so that we can effectively detect a subsidence in the coastal reclaimed area especially using pixels of high coherence (>0.5). The maximum accumulated subsidence was about 60 cm in the study area, while the subsidence in the northern and south western areas were less than 20 cm. The resuts show that DInSAR is extremely useful for geotechnical applications as well as observation of natural deformation.

JERS-1 L-밴드 SAR 위성에서 얻어진 5개의 interferogram을 이용하여 1996년 5월 2일부터 1998년 2월 21일 사이 연안매립지인 녹산 국가산업단지의 공단조성과정에서 발생한 지반침하량을 계산하였다. 약 16 m의 공간해상도를 갖는 레이더 관측결과는 현장측정 자료로부터 관측되기 어려운 세밀한 침하 양상을 잘 반영하였다. 정확도 검증을 위해 2-pass DInSAR로 구한 침하량을 Magnetic Probe Extensometer(측정정밀도:${\pm}$1 mm)를 사용하여 총 42개소에 서 측정된 현장자료와 비교하였다. 5개의 쌍으로부터 추정된 DInSAR침하량과 실측침하량의 평균 상관계수는 0.77 이다. 추정된 DInSAR 침하량 중 0.5 이상의 긴밀도를 갖는 점들만을 이용하여 계산한 경우 상관계수는 0.87이며, RMSE는 1.44 cm로 더욱 좋은 결과를 나타낸다. 또한 추정된 회귀선의 기울기는 1.04로 실측값과 DInSAR 추정값이 기울기 1에 가까운 선형관계를 잘 만족하고 있음을 보여준다. 즉 DInSAR 결과 긴밀도 0.5 이상의 지점을 이용하면 효과적으로 연안매립지의 침하량을 관측할 수 있다. DInSAR를 이용하여 계산된 녹산 국가산업단지에서 발생한 최대 누적침하량은 약 60 cm 정도이며, 연구지역의 북쪽과 남서쪽에서는 약 20 cm 이하의 침하가 관측되었다. 이러한 결과는 자연적인 지표변위 관측뿐만 아니라 지반공학적 응용분야에서도 DInSAR 기술이 매우 중요한 역할을 맡을 수 있음을 보여준다.

Keywords

References

  1. 국립지리원 내규 제 71호 수지지도작성 작업내규 국립지리원
  2. 녹산국가공단 개발사업 부지조성공사 연약지반 침하안정관리용역 종합보고서 한국토지공사
  3. 연약지반의 처리공법과 침하계측에 관한 연구 한국토지공사
  4. 연세대학교 석사학위논문 L-밴드 JERS-1 SAR를 이용한 매립지 지반침하 관측-녹산·신호공단을 중심으로 이창욱
  5. Nature v.407 Widespread uplift and trapdoor faulting on Galapagoes observed with radar interferometry Amelung F.;Jonnson S.;Zebker H.A.;Segall, P. https://doi.org/10.1038/35039604
  6. Proc. IGARSS 2002 Ground Deformation Monitoring Exploiting SAR Permanent Scatterers Colesanti C.;Locatelli R.;Novali F.
  7. Proc. FRINGE 96 Workshop The Developing of a Wide Area Interferometric Processor. Carrasco D.;Sanz S.;Sousa R.;Broquetas A.
  8. IEEE Trans. Geosci. Remote Sensing v.38 no.5 Nonlinear Subsidence Rate Estimation Using Permanent Scatteres in Differential SAR Interferometry. Ferretti A;Prati C.;Rocca F. https://doi.org/10.1109/36.868878
  9. IEEE Trans. Geosci. Remote Sensing v.39 no.1 Permanent Scatterers in SAR Interferometry. Ferrettti A;Prati C.;Rocca F. https://doi.org/10.1109/36.898661
  10. Geophys. Res. Lett. v.27 no.24 Detection of ground subsidence in the city of Paris using radar interferometry: isolation of deformation from atmospheric artifacts using correlation Fruneau B.;Sarti F. https://doi.org/10.1029/2000GL008489
  11. J. Opt. Soc. Am. A v.14 no.10 Two-dimensional phase unwrapping with minimum weighted discontinuity. Flynn T.J. https://doi.org/10.1364/JOSAA.14.002692
  12. J. Geophys. Res. v.94 Mapping small elevation changes over large areas: Differential radar interferometry. Gabriel A.K.;Goldstein R.M.;Zebker H.A. https://doi.org/10.1029/JB094iB07p09183
  13. Radio Sci. v.23 Satellite radar interferometry: two-dimensional phase unwrapping Goldstein R.M.;Zebker H.A.;Werner C.L. https://doi.org/10.1029/RS023i004p00713
  14. Science v.283 High-resolution water vapor mapping from interferometric radar measurements. Hanssen, R.F.;Weckwerth H.A.;Zebker H.A.;Klees R. https://doi.org/10.1126/science.283.5406.1297
  15. Science v.274 A mini-surge on the Ryder Glacier, Greenland, observed via satellite radar interferometry Joughin I.;Tulaczyk S.;Fahnestock M.;Kwok R. https://doi.org/10.1126/science.274.5285.228
  16. IEEE Trans. Geosci. Remote Sensing v.31 Radar interferometry: Limits and potential. Massonnet D.;Rabaute T. https://doi.org/10.1109/36.214922
  17. Nature v.364 The displacement field of the Landers earthquake mapped by radar interferometry. Massonnet D.;Rossi M.;Carmona C.;Adragna, F.;Peltzer G.;Fiegl K.;Rabaute T. https://doi.org/10.1038/364138a0
  18. Nature v.375 Deflation of Mount Etna monitored by spaceborne radar interferometry. Massonnet D.;Briole P.;Arnaud A. https://doi.org/10.1038/375567a0
  19. Rev. Geophys. v.36 Radar interferometry and its application to changes in the earth's surface. Massonnet D.;Feigl K.L. https://doi.org/10.1029/97RG03139
  20. Proc. FRINGE 96 Workshop Impact of Precise orbits on SAR interferometry Reigber C.;Xia Y.;Kaufmann H.;Timmen T.;Bodechtel J.;Frei M.
  21. J. Geophys. Res. v.103 Precise orbir determination and gravity field improvement for the ERS satellites. Scharroo, R.;Visser P.N.A.M. https://doi.org/10.1029/97JC03179
  22. Photogrammetric Engineering & Remote Sensing v.67 no.11 Land subsidence Monitoring with Differential SAR Interferometry. Strozzi T.;Wegm, IIer U.;Gitelli G;Spreckels V.
  23. Geophys. Res. Lett. v.23 Atmospheric propagation heterogeneities revealed by ERS-1 interferometry. Tarayre H.;D. Massonnet https://doi.org/10.1029/96GL00622
  24. IEEE trans. Geosci. Remote Sensing v.30 Decorrelation in interferometric radar echoes. Zebker H.A.;Villasenor J. https://doi.org/10.1109/36.175330
  25. IEEE Trans. Geosci. Remote Sensing v.32 Accuracy of topographic maps derived from ERS-1 interferometric radar. Zebker H.A.;Werner C.L.;Rosen P.A.;Hensley S. https://doi.org/10.1109/36.298010
  26. J. Geophys. Res. v.99 no.B10 On the derivation of coseismic displacement fields using differential radar interferometry: The Landers earthquake. Zebker H.A.;Rosen P.A.;Goldstein R.M.;Gabriel A.;Werner C.L. https://doi.org/10.1029/94JB01179