07이재희(3p)(123~131)ok

Size: px

Start display at page:

Download "07이재희(3p)(123~131)ok"

일섭 길
5 years ago
Views:

1 Korean Journal of Remote Sensing, Vol.26, No.2, 2010, pp.123~131 Detection of Artificial Displacement of a Reflector by using GB-SAR Interferometry and Atmospheric Humidity Correction Jae-Hee Lee*, **, Hoonyol Lee*, Seong-Jun Cho**, Nak-Hoon Sung**, and Jung-Ho Kim** *Department of Geophysics, Kangwon National University **Mineral Resources Research Division, Korea Institute of Geoscience and Mineral Resources Abstract : In this paper we applied Ground-Based Synthetic Aperture Radar(GB-SAR) interferometry to detect artificial displacement of a reflector and performed an atmospheric humidity correction to improve the accuracy. A series of GB-SAR images were obtained using a center frequency of 5.3 GHz with a range resolution of 25 cm and a azimuth resolution of 0.324, all in fullpolarization (HH, VV, VH, HV) modes. A triangular trihedral corner reflector was located 160 m away from the system, and the artificial displacements of 0-40 mm was implemented during the GB-SAR image acquisition. The result showed that the RMS error between the actual and measured displacements, averaged in all polarization data, was 1.22 mm, while the maximum error in case of the 40 mm displacement was 2.72 mm at HH-polarization. After the atmospheric correction with respect to the humidity, the RMS error was reduced to 0.52 mm. We conclude that a GB-SAR system can be used to monitor the possible displacement of artificial/natural scatterers and the stability assessment with sub-millimeter accuracy. Key Words : GB-SAR, interferometry, displacement, atmospheric humidity correction. hoonyol@kangwon.ac.kr 123

2 Korean Journal of Remote Sensing, Vol.26, No.2, 2010 Table 1. Parameters for the GB-SAR experiment. Measurement parameters Center frequency 5.3 GHz Range bandwidth 600 MHz IF Bandwidth 1 khz Number of sampling 1601 Power 33 dbm Azimuth Step 0.05 m Azimuth length 5 m 124

Photos of the experimental setup. (a) GB-SAR system.

The 4 check symbols are the stable targets while the triangle represent the

(c) Side view of the reflector on top of a acrylic plate.

3 Detection of Artificial Displacement of a Reflector by using GB-SAR Interferometry and Atmospheric Humidity Correction (a) (b) (c) Fig. 1. Photos of the experimental setup. (a) GB-SAR system. (b) Aerial view of experiment location. The 4 check symbols are the stable targets while the triangle represent the location of the triangular trihedral corner reflector. (c) Side view of the reflector on top of a acrylic plate. (d) Top view of the reflector with the scale-bar on the plate. (d) (a) HH (b) VV (c) VH (d) HV Fig. 2. GB-SAR amplitude images of (a) HH, (b) VV, (c) VH, and (d) HV polarization. The reflector signal is much stronger in copolarization than cross-polarization images due to the nature of a triangular trihedral corner reflector used in this experiment. 125

4 Korean Journal of Remote Sensing, Vol.26, No.2, 2010 Table 2. Coefficients of atmospheric correction function. Df = 4pR(ah b), [47% h 58%] a b HH VV VH HV l j = 4p R (1) l j n j 0 = 4p (R n R 0 ) = 4p r n (2) l l d j = 4p (3) dr l Table 3. RMS errors between the measured and actual displacements before and after atmospheric humidity corrections RMS error Before Atmospheric After Atmospheric humidity Polarization Correction(mm) Correction(mm) HH VV VH HV Average

5 Detection of Artificial Displacement of a Reflector by using GB-SAR Interferometry and Atmospheric Humidity Correction (a) (b) (c) Fig. 3. Comparisons between the actual and measured displacements in (a) HH, (b) VV, (c) VH, and (d) HV polarization. (d) Fig. 4. Atmospheric relative humidity during the two days including the measurement time. 127

6 Korean Journal of Remote Sensing, Vol.26, No.2, 2010 (a) (b) (c) Fig. 5. Relationship between relative humidity and phase/range values extracted from the stable targets (4 targets 6 measurement = 24 data points) at each polarization. (d) Dj = 4p(ah b) (4) R a b 128

7 Detection of Artificial Displacement of a Reflector by using GB-SAR Interferometry and Atmospheric Humidity Correction (a) (b) (c) Fig. 6. Comparisons between the actual and the atmospherically corrected displacement in (a) HH, (b) VV, (c) VH, and (d) HV polarization. (d) 129

8 Korean Journal of Remote Sensing, Vol.26, No.2, 2010 Abellan, A., Vilaplana, J.M., Martinez, J., Application of a long-range Terrestrial Laser Scanner to a detailed rockfall study at Vall de Nuria(Eastern Pyrenees, Spain). Engineering geology, Vol.88(3-4), Casagli, N., P. Farina, D. Leva, G. Nico, and D. Tarchi, Ground-Based SAR interferometry as a tool for landslide monitoring during emergencies IGARSS, Toulouse, France, July, Vol.4, Lee, J. J and M. Shinozuka, A vision-based system for remote sensing of bridge displacement, NDT&E International, 39(5): LI, H. N., D. S. Li, and G. B. Song, Recent application of fiber optic sensors to health monitoring in civil engineering, Engineering Structures, 26(11): Leva, D., G. Nico, D. Tarchi, J. F. Guasch, and J. Sieber, Temporal analysis of a Ground- Based SAR interferometry, IEEE Transactions on Geoscience and Remote Sensing, 41(4): Luzi, G., M. Pieraccini, D. Mecatti, L. Noferini, G. Guidi, F. Moia, and C. Atzeni, Ground- Based Radar interferometry for landslides monitoring: Atmospheric and instrumental decorrelation sources on experimental data, IEEE Transactions on Geoscience and Remote Sensing, 42(11): Luzi, G., M. Pieraccini, D. Mecatti, L. Noferini, G. Macaluso, A. Tamburini and C. Atzeni Monitoring of an Alpine glacier by means of Ground-Based SAR interferometry, IEEE Transactions on Geoscience and Remote Sensing, 4(3): Monserrat, O. and Crosetto, M., Deformation measurement using terrestrial laser scanning data and least squares 3D surface matching. ISPRS Journal of Photogrammetry and Remote Sensing, 63(1), Nickitopoulou, A., K. Protopsalti, and S. Stiros, Monitoring dynamic and quasi-static deformations of large flexble engineering structures with GPS: Accuracy, limitations and promises, Engineering Structure, 28(10): Noferini, L., M. Pieraccini, D. Mecatti, G. Luzi, C. Atzeni, A. Tamburini, and M. Broccolato, Permanent Scatterers analysis for atmospheric correction in Ground-Based SAR 130

9 Detection of Artificial Displacement of a Reflector by using GB-SAR Interferometry and Atmospheric Humidity Correction interferometry, IEEE Transactions on Geoscience and Remote Sensing, 43(7): Noferini, L., M. Pieraccini, D. Mecatti, G. Macaluso, C. Atzeni, M. Mantovani, G. Marcato, A. Pasuto, S. Silvano and F. Tagliavini, Using GB-SAR technique to monitor show moving landslide, Engineering Geology, 95(3-4): Pieraccini, M., D. Mecatti, L. Noferini, G. Luzi, G. Franchioni, and C. Atzeni, SAR interferometry for detecting the effects of earthquakes on buildings, NDT&E International, 35(2002): Pipia, L., X. Fabregas, A. Aguasca, and C. L. Martinez, Atmospheric artifact compensation in Ground-Based DInSAR application, IEEE Transactions on Geoscience and Remote Sensing, 5(1): Tamura, Y., M. Matsui, L. C. Pagnini, R. Ishibashi, and A. Yoshida, Measurement of windinduced response of buildings using RTK- GPS, Journal of Wind Engineering and Industrial Aerodynamics, 90(12-15): Tarchi, D., H. Rudolf, G. Luzi, L. Chiarantini, P. Coppo, and A.J. Sieber, SAR interferometry for structural changes detection: A demonstration test on a dam, 1999 IGARSS, Hamburg, Germany, 28 June-2 July, Vol.4, Tarchi, D., N. Casagli, R. Fanti, D. D. Leva, G. Luzi, A. Pasuto, M. Pieraccini, and S. Silvano, Landslide monitoring by using Ground-Based SAR interferometry: an example of application to the Tessina landslide in Italy, Engineering Geology, 68(1-2):

09이훈열ok(163-

09이훈열ok(163- Korean Journal of Remote Sensing, Vol.27, No.2, 2011, pp.163~170 Change of Refractive Index of Air in X-band due to Atmospheric Humidity, Temperature and Pressure measured by GB-SAR Interferometry Jae-Hee