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Delen A, Sanli FB, Abdikan S, Dogan AH, Durdag UM, Ocalan T, Erdogan B, Calò F, Pepe A. A Statistical Approach for the Integration of Multi-Temporal InSAR and GNSS-PPP Ground Deformation Measurements. Sensors (Basel) 2023; 24:43. [PMID: 38202905 PMCID: PMC10780305 DOI: 10.3390/s24010043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/17/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024]
Abstract
Determining and monitoring ground deformations is critical for hazard management studies, especially in megacities, and these studies might help prevent future disaster conditions and save many lives. In recent years, the Golden Horn, located in the southeast of the European part of Istanbul within a UNESCO-protected region, has experienced significant changes and regional deformations linked to rapid population growth, infrastructure work, and tramway construction. In this study, we used Interferometric Synthetic Aperture Radar (InSAR) and Global Navigation Satellite System (GNSS) techniques to investigate the ground deformations along the Golden Horn coastlines. The investigated periods are between 2015 and 2020 and 2017 and 2020 for InSAR and GNSS, respectively. For the InSAR analyses, we used sequences of multi-temporal synthetic aperture radar (SAR) images collected by the Sentinel-1 and ALOS-2 satellites. The ground displacement products (i.e., time series and velocity maps) were then cross-compared with those achievable using the Precise Point Positioning (PPP) technique for the GNSS solutions, which can provide precise positions with a single receiver. In the proposed analysis, we compared the ground displacement velocities obtained by both methods by computing the standard deviations of the difference between the relevant observations considering a weighted least square estimation procedure. Additionally, we identified five circle buffers with different radii ranging between 50 m and 250 m for selecting the most appropriate coherent points to conduct the cross-comparison analysis. Moreover, a vertical displacement rate map was produced. The comparison of the vertical ground velocities derived from PPP and InSAR demonstrates that the PPP technique is valuable. For the coherent stations, the vertical displacement rates vary between -4.86 mm/yr and -23.58 mm/yr and -9.50 and -27.77 mm/yr for InSAR and GNSS, respectively.
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Affiliation(s)
- Ahmet Delen
- Department of Geomatics Engineering, Gaziosmanpasa University, 60150 Tokat, Türkiye; (A.D.); (A.H.D.)
| | - Fusun Balik Sanli
- Department of Geomatic Engineering, Yildiz Technical University, 34220 Esenler, Istanbul, Türkiye; (F.B.S.); (T.O.); (B.E.)
| | - Saygin Abdikan
- Department of Geomatics Engineering, Hacettepe University, 06800 Ankara, Türkiye;
| | - Ali Hasan Dogan
- Department of Geomatics Engineering, Gaziosmanpasa University, 60150 Tokat, Türkiye; (A.D.); (A.H.D.)
| | - Utkan Mustafa Durdag
- Department of Geomatic Engineering, Artvin Coruh University, 08100 Artvin, Türkiye;
| | - Taylan Ocalan
- Department of Geomatic Engineering, Yildiz Technical University, 34220 Esenler, Istanbul, Türkiye; (F.B.S.); (T.O.); (B.E.)
| | - Bahattin Erdogan
- Department of Geomatic Engineering, Yildiz Technical University, 34220 Esenler, Istanbul, Türkiye; (F.B.S.); (T.O.); (B.E.)
| | - Fabiana Calò
- Institute for the Electromagnetic Sensing of the Environment (IREA), National Research Council (CNR) of Italy, Via Diocleziano 328, 80124 Napoli, Italy;
| | - Antonio Pepe
- Institute for the Electromagnetic Sensing of the Environment (IREA), National Research Council (CNR) of Italy, Via Diocleziano 328, 80124 Napoli, Italy;
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