scholarly journals Long-Term Land Deformation Monitoring Using Quasi-Persistent Scatterer (Q-PS) Technique Observed by Sentinel-1A: Case Study Kelok Sembilan

2018 ◽  
Vol 07 (04) ◽  
pp. 277-289 ◽  
Author(s):  
Pakhrur Razi ◽  
Josaphat Tetuko Sri Sumantyo ◽  
Daniele Perissin ◽  
Hiroaki Kuze
2019 ◽  
Author(s):  
Pakhrur Razi

Located on the mountainous area, Kelok Sembilan flyover area in West Sumatra, Indonesia has a long history of land deformation, therefore monitoring and analyzing as continuously is a necessity to minimize the impact. Notably, in the rainy season, the land deformation occurs along this area. The zone is crucial as the center of transportation connection in the middle of Sumatra. Quasi-Persistent Scatterer (Q-PS) Interferometry technique was applied for extracting information of land deformation on the field from time to time. Not only does the method have high performance for detecting land deformation but also improve the number of PS point, especially in a non-urban area. This research supported by 90 scenes of Sentinel-1A (C-band) taken from October 2014 to November 2017 for ascending and descending orbit with VV and VH polarization in 5 × 20 m (range × azimuth) resolution. Both satellite orbits detected two critical locations of land deformation namely as zone A and Zone B, which located in positive steep slope where there is more than 500 mm movement in the Line of Sight (LOS) during acquisition time. Deformations in the vertical and horizontal direction for both zone, are 778.9 mm, 795.7 mm and 730.5 mm, 751.7 mm, respectively. Finally, the results were confirmed by ground truth data using Unmanned Aerial Vehicle (UAV) observation.


Author(s):  
M. Crosetto ◽  
O. Monserrat ◽  
A. Barra ◽  
M. Cuevas-González ◽  
V. Krishnakumar ◽  
...  

<p><strong>Abstract.</strong> This paper describes a Persistent Scatterer Interferometry procedure for deformation monitoring. Its more original part concerns an approach to estimate the atmospheric phase component. The procedure can be used to monitor deformation areas that are relatively small and are surrounded by stable areas. The proposed procedure is described step by step. The procedure can be applied using SAR data coming from different sensors. However, in this work we discuss results obtained using Sentinel-1 data. A case study is described, where the deformation is caused by water pumping associated with construction works. In this case study, a stack of 78 Sentinel-1 images were analysed. The main part of the paper concerns the analysis of the atmospheric component. A comprehensive characterization of this component is first described, considering the original non-filtered phases. This is followed by the characterization of the residual filtered phases. This analysis highlights the goodness of the proposed procedure. This is further confirmed by the analysis of two deformation time series. The procedure can work with any type of deformation phenomena, provided that its spatial extension is sufficiently small.</p>


IEEE Access ◽  
2018 ◽  
Vol 6 ◽  
pp. 12395-12404 ◽  
Author(s):  
Pakhrur Razi ◽  
Josaphat Tetuko Sri Sumantyo ◽  
Daniele Perissin ◽  
Hiroaki Kuze ◽  
Ming Yam Chua ◽  
...  

2018 ◽  
Vol 203 ◽  
pp. 04002
Author(s):  
Amir Sharifuddin Ab Latip ◽  
Abd Nasir Matori ◽  
Anuphao Aobpaet

The Interferometric Synthetic Aperture Radar (InSAR) technique is well established technique for onshore applications such as landslide, mining, volcano, urban and dam deformation monitoring. However, the ability of the InSAR technique for the offshore application particularly on the oil platform deformation monitoring is still a pending question. Therefore, a study needs to be conducted in order to assess the feasibility of the InSAR technique for monitoring the deformation of offshore platform. In this study, an advanced InSAR technique called Stanford Method of Persistent Scatterer (StaMPS) was utilized to process a stack of TerraSAR-X data. A mask has been developed as an additional module in the StaMPS to remove the noise on the ocean and relax the assigned condition imposed on the processing parameters. The results show that the number of persistent scatterer (PS) points on the offshore platform increased from 15 to 22 points and a smoother pattern of the velocity estimation could be seen when masking was applied to identify the deformation. Furthermore, some limitations and possible solutions of the PSI technique on the offshore platform application are summarized in this paper to guide future users on this application.


2018 ◽  
Author(s):  
Ketut Wikantika

Since the introduction of the persistent scatterer technique (PS-InSAR) in the early 1999, the applicability of radar interferometry has increased considerably.In this research, PS-InSAR technique is proposed to retrieve the volume change of long-term continuously land deformation. This technique is used to analyze subsidence in Bandung City, West Java-Indonesia by assessing 19 ALOS PALSAR images (Japanese L band spaceborne) during the periods of July 2007-February 2011. In this research, data are optimized by reducing set data images with iterative PS-InSAR processing. This PS-InSAR processing chain based on a rigid quality assessment of the estimated parameter like minimum coherence (0.9) and PS density point (200), in order to get an optimum quality of light PS-InSAR (LPS-InSAR) concept technique. Moreover, a strict quality validation of PS-InSAR with other geodetic techniques such as DInSAR and GPS methods. The result of validation has resulted such as 1,4 ± 1,4 cm/year (PS InSAR-DInSAR) and 1,6 ± 0,7 cm/year (PS-InSAR-GPS). For land subsidence velocity in Bandung City has results between 0,6 ± 0,4 cm/year and 2,1 ± 1,2 cm/year. This research shows a capability of data optimalization in PS-InSAR technique as basic concept of LPS-InSAR processing.


2020 ◽  
Vol 29 (4) ◽  
pp. 2049-2067
Author(s):  
Karmen L. Porter ◽  
Janna B. Oetting ◽  
Loretta Pecchioni

Purpose This study examined caregiver perceptions of their child's language and literacy disorder as influenced by communications with their speech-language pathologist. Method The participants were 12 caregivers of 10 school-aged children with language and literacy disorders. Employing qualitative methods, a collective case study approach was utilized in which the caregiver(s) of each child represented one case. The data came from semistructured interviews, codes emerged directly from the caregivers' responses during the interviews, and multiple coding passes using ATLAS.ti software were made until themes were evident. These themes were then further validated by conducting clinical file reviews and follow-up interviews with the caregivers. Results Caregivers' comments focused on the types of information received or not received, as well as the clarity of the information. This included information regarding their child's diagnosis, the long-term consequences of their child's disorder, and the connection between language and reading. Although caregivers were adept at describing their child's difficulties and therapy goals/objectives, their comments indicated that they struggled to understand their child's disorder in a way that was meaningful to them and their child. Conclusions The findings showed the value caregivers place on receiving clear and timely diagnostic information, as well as the complexity associated with caregivers' understanding of language and literacy disorders. The findings are discussed in terms of changes that could be made in clinical practice to better support children with language and literacy disorders and their families.


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