Paper Info
Title
Monitoring Coastal Reclamation Subsidence in Hong Kong with Distributed Scatterer Interferometry.
Abstract
Land subsidence has been a significant problem in land reclaimed from the sea, and it is usually characterized by a differential settlement pattern due to locally unconsolidated marine sediments and fill materials. Time series Synthetic Aperture Radar Interferometry (InSAR) techniques based on distributed scatterers (DS), which can identify sufficient measurement points (MPs) when point-wise radar targets are lacking, have great potential to measure such differential reclamation settlement. However, the computational time cost has been the main drawback of current distributed scatterer interferometry (DSI) for its applications compared to the standard PSI analysis. In this paper, we adopted an improved DSI processing strategy for a fast and robust analysis of land subsidence in reclaimed regions, which is characterized by an integration of fast statistically homogeneous pixel selection based (FaSHPS-based) DS detection and eigendecomposition phase optimization. We demonstrate the advantages of the proposed DSI strategy in computational efficiency and deformation estimation reliability by applying it to two TerraSAR-X image data stacks from 2008 to 2009 to retrieve land subsidence over two typical reclaimed regions of Hong Kong International Airport (HKIA) and Hong Kong Science Park (HKSP). Compared with the state-of-the-art DSI methods, the proposed strategy significantly improves the computational efficiency, which is enhanced approximately 30 times in DS identification and 20 times in phase optimization. On average, the DSI strategy results in 7.8 and 3.7 times the detected number of MPs for HKIA and HKSP with respect to persistent scatter interferometry (PSI), which enables a very detailed characterization of locally differential settlement patterns. Moreover, the DSI-derived results agree well with the levelling survey measurements at HKIA, with a mean difference of 1.87 mm/yr and a standard deviation of 2.08 mm/yr. The results demonstrate that the proposed DSI strategy is effective at improving target density, accuracy and efficiency in monitoring ground deformation, particularly over reclaimed coastal areas.
Year
DOI
Venue
2018
10.3390/rs10111738
REMOTE SENSING
Keywords
Field
DocType
Synthetic Aperture Radar Interferometry (InSAR),persistent scatterers,distributed scatterers,efficiency,reclamation subsidence,Hong Kong
Remote sensing,Interferometry,Subsidence,Land reclamation,Geology
Journal
Volume
Issue
Citations 
10
11
0
PageRank 
References 
Authors
0.34
0
6
Name
Order
Citations
PageRank
Qishi Sun112.10
Liming Jiang254.69
Mi Jiang300.34
Hui Lin445964.06
Peifeng Ma5122.36
Hansheng Wang6187.27