Integration of SAR and optical images to measure the 3D coseismic deformation in hanging wall of Chelungpu Fault during 1999 Chi-Chi earthquake
Abstract
The InSAR technique has became one of the most powerful geodetic tools to measure the surface deformation in many geoscience fields, such as earthquake, volcano, and glacier. Due to the conventional InSAR supports the 1D displacement information in line-of-sight ( LOS) direction, many scientists used different methods of image analysis, such as pixel offset and MAI, to detect more spatial information for measuring the 3D surface deformation.
However, the low coherence between two SAR images and huge virtual displacement limited the conventional InSAR and MAI. Moreover, the temporal decorrelation influenced the accuracy of pixel offset result. These factors caused difficulty to measure the coseismic deformation of Chi-Chi earthquake in the hanging wall of Chelungpu Fault. For overcoming these limitations, we use the SAR and optical images to estimate the 3D displacement. The optical image constrained the horizontal movement and reduced the temporal decorrelation. The SAR image contributed the component of vertical movement. Our results indicate that the RMS of vertical displacement between the GPS data and integration results ( 0.35 m) is lower than the RMS ( 0.48 m) between GPS data and the inversion results from azimuth and range offset of SAR image. Moreover, the integration results present similar pattern with the displacement of field measuring data along the fault and match with the activity behavior of geological structure.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.G13C0552L
- Keywords:
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- 1240 Satellite geodesy: results;
- GEODESY AND GRAVITY;
- 1241 Satellite geodesy: technical issues;
- GEODESY AND GRAVITY;
- 1294 Instruments and techniques;
- GEODESY AND GRAVITY;
- 1295 Integrations of techniques;
- GEODESY AND GRAVITY