Abstract
Owing to the development of spaceborne synthetic aperture radar (SAR) platforms, and in particular the increase in the availability of multi-source (multi-band and multi-resolution) data, it is now feasible to design a surface displacement monitoring application using multi-temporal SAR interferometry (MT-InSAR). Landslides have high socio-economic impacts in many countries because of potential geo-hazards and heavy casualties. In this study, taking into account the merits of ALOS PALSAR (L-band, good coherence preservation) and TerraSAR (X-band, high resolution and short revisit times) data, we applied an improved small baseline InSAR (SB-InSAR) with 3-D phase unwrapping approach, to monitor slope superficial displacement in Hong Kong, China, a mountainous subtropical zone city influenced by over-urbanization and heavy monsoonal rains. Results revealed that the synergistic use of PALSAR and TerraSAR data produces different outcomes in relation to data reliability and spatial-temporal resolution, and hence could be of significant value for a comprehensive understanding and monitoring of unstable slopes.
Highlights
A landslide is the movement of a mass of rock, debris, or earth down a slope under the influence of gravity [1], threatening infrastructures, residential zones, and cultural heritage sites
A majority of landslides in Hong Kong occurred on slopes with gradients less than 60°, and have been covered by the range of current
PALSAR data were used for large-scale natural scenarios monitoring owing to its width swath and high coherence preservation in vegetated areas
Summary
A landslide (resulting from slope instability) is the movement of a mass of rock, debris, or earth down a slope under the influence of gravity [1], threatening infrastructures, residential zones, and cultural heritage sites. MT-InSAR measures the phase difference of two or multi-temporal SAR acquisitions and can be divided into two categories: persistent scatterer (PS) SAR interferometry (PS-InSAR) [13,14,15] and small baseline SAR interferometry (SB-InSAR) [16,17,18,19]. The former identifies pixels primarily on phase variation in time or phase correlation in space, corresponding to point-like targets or so-called PS points (e.g., man-made structures, boulders and outcrops), and the full resolution can be preserved. Merits of the two different SAR systems, large spatial coverage of ALOS PALSAR and detailed information extraction of TerraSAR-X, are integrated enabling a comprehensive understanding and monitoring of unstable slopes
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
