Abstract
Interferometric Synthetic Aperture Radar (InSAR) is a radar technique to generate map of surface deformation using phase differences acquired at different times. The InSAR technique measures these phase differences in its line of sight (LOS). Regarding LOS projection to a ground coordinate system, the combination of SAR data from ascending and descending can estimate at least two dimensional fields which are vertical and east-west components and three dimensional fields with either an additional motion model or vector displacements from along-track direction. The purpose of this work is to generate 2D and 3D vector displacements from two different InSAR tracks (e.g. ascending and descending) with a calculation programme both for the mean velocity and time series data named as PS DISP. 2D mode is calculated in which the north-south component is neglected due to insensitive along the flight direction, thus, assuming to be zero (0). On the other hand, 3D mode is calculated with an assumption that the northsouth component moves along the elevation downward. The experimental results were conducted for the Puncak Pass and Puncak Highway landslides and the Lombok earthquake in Indonesia. For the landslide study, the computation generated the movement towards the slope surface in the 3D Cartesian coordinate (dU,dE, and dN (psuedo)) and found both the crown body and cumulative zone of the landslide. For the earthquake study, PS DISP decomposed 2D vectors (dU and dE). The area of earthquake rupture was lifted by 42 cm and other northern Lombok areas by 10 - 25 cm. Regarding the west-eastern motion, it shows that the west of northern Lombok was displaced ±5 cm toward the west direction, while the other side to the east direction.
Keywords: InSAR, 2D and 3D displacements, slope aspect, ground motion, landslide, earthquake
References
Bechor, Noa B. D. and Howard A. Zebker, 2006. “Measuring two-dimensional movements using a single InSAR pair”. In: Geophysical Research Letters 33.16. L16311.
Ferretti, Allesandro, 2014. Satellite InSAR Data. Reservoir Monitoring from Space. European Association of Geoscientist and Engineers.
Floriane Provost, Alexander L Handwerger, 2018. “Combining Sentinel-1 and Ground-based SAR to retrieve landslide 3D displacement: application to Pas de l’Ours landslide, France”. In: URL: https : / / agu . confex . com / agu / fm18 /meetingapp.cgi/Paper/448147.
Grandin, R. et al., 2016. “Three-dimensional displacement field of the 2015 Mw8.3 Illapel earthquake (Chile) from across- and along-track Sentinel-1 TOPS interferometry”. In: Geophysical Research Letters 43.6, pp. 2552–2561. doi: 10 . 1002 / 2016GL067954.
Hanssen, R.F., 2001. Radar Interferometry: Data Interpretation and Error Analysis. Remote Sensing and Digital Image Processing. Springer Netherlands.
Hooper A., Bekaert D., Spaans K., Arikan M., 2012. Recent advances in SAR interferometry time series analysis for measuring crustal deformation, Tectonophysics, 514-517, pp.1-13. doi: 10.1016/j.tecto.2011.10.013.
Hu, J. et al., 2014. “Resolving three-dimensional surface displacements from InSAR measurements: A review”. In: Earth-Science Reviews 133, pp. 1 –17.
Isya, N. H., Niemeier, W., and Gerke, M.: 3D Estimation of Slow Ground Motion Using InSAR and The Slope Aspect Assumption, A Case Study: The Puncak Pass Landslide, Indonesia, ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., IV-2/W5, 623-630, https://doi.org/10.5194/isprs-annals-IV-2-W5-623-2019, 2019.
Mohr, J. J, 1997. “Repeat Track SAR Interferometry. An investigation of its Utility for Studies of Glacier Dynamics”.PhD thesis. Technical University of Denmark, Copenhagen.
Notti, Davide et al., 2015. “A User-Oriented Methodology for DInSAR Time Series Analysis and Interpretation: Landslides and Subsidence Case Studies”. In: Pure and Applied Geophysics 172.11, pp. 3081–3105. ISSN: 1420-9136. DOI:10.1007/s00024-015-1071-4.
Ramdani, F., Setiani, P. and Setiawati, D., 2019. Analysis of sequence earthquake of Lombok Island, Indonesia. Progress in Disaster Science, 4, p.100046.
Sadarviana, Vera, 2006. “Pemanfaatan Metode Geodetik untuk Mengestimasi Karakteristik Tipe dan Bidang Gelincir pada Zona Longsor, Wilayah Studi: Zona Longsor Ciloto-Puncak, Jawa Barat”. PhD thesis. Institut Teknologi Bandung.
Sandwell, D.; Rob.; Xiaopeng.; Xu, X.; Wei, M.; Wessel, P., 2016. GMTSAR: An InSAR Processing System Based on Generic Mapping Tools (Second Edition); Scripps Institution of Oceanography, University of California, San Diego.
Smith, W. H. F. and P. Wessel, 1990. “Gridding with continuous curvature splines in tension”. In: Geophysics 55.3, pp. 293–305. ISSN: 0016-8033. DOI: 10.1190/1.1442837.
Vollrath, Andreas et al., 2017. “Decomposing DInSAR Time Series into 3-D in Combination with GPS in the Case of Low Strain Rates: An Application to the Hyblean Plateau, Sicily, Italy”. In: Remote Sensing 9.1. DOI: 10.3390/rs9010033.
Wright, Tim J., Barry E Parsons, and Zhong Lu, 2004. “Toward mapping surface deformation in three dimensions using InSAR”. In: Geophysical Research Letters 31.1. DOI: 10 . 1029 / 2003GL018827.