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Annual Results Report
Terrain Measurement (id. 10569) 22-26 June, 2015
DerenLi, Mingsheng Liao, Lu Zhang, Timo Balz LIESMARS, Wuhan University
Outline • Overview
• Research Activities and Results
Part 1. Monitoring ground subsidence in Shanghai
Part 2. Monitoring landslide stability in Three Gorges and NE China
• Conclusion & Discussion
Overview
Chinese Partners • Prof. Deren LI (PI) Prof. Mingsheng LIAO (Co-PI), LIESMARS, Wuhan University • Mrs. Hanmei WANG, Shanghai Institute of Geological Survey • Young scientists in Wuhan and Shanghai: Dr. Lu Zhang, Prof. , LIESMARS, Wuhan University Dr. Timo Balz, Prof. , LIESMARS, Wuhan University Mr. Michael Jendryke, Ph.D student, LIESMARS, Wuhan University Ms. Mengshi Yang, Ph.D student, LIESMARS, Wuhan University Mr. Xuguo Shi, Ph.D student, LIESMARS, Wuhan University Ms. Yanan Jiang , Ph.D student, LIESMARS, Wuhan University
European Partners
• Prof. Fabio Rocca (PI) • Dr. Stefano Tebaldini (Co-PI)
Dipartimento di Elettronica ed Informazione Politecnico di Milano (POLIMI), Italy
• Young scientists in Milan: Mr. Simone Mancon, Ph.D student, POLIMI
Project Objectives
Based on the fruitful results of Dragon-1&2, the scientific investigations still focus on: – Topographic mapping – Deformation monitoring (subsidence, landslide) – SAR tomography in presence of vegetation
• Prof. Fabio Rocca gave the course on SAR remote sensing and open lecture for postgraduate students during the Spring semester 2015 at LIESMARS, Wuhan University.
Academic Exchange
Young Scientists’ Activities (1) • Mr. Simone Mancon visited LIESMARS, WHU from May to June in 2015.
Meeting at Prof.Liao’s office
Giving lecture for students
Young Scientists’ Activities (2)
•Lai Xudong, a young scientist of WHU worked at ESRIN for one year under Dragon training and research program.
• Shi Xuguo, a PhD student made an oral presentation at Fringe workshop@Frascati in March 2015.
Journal Papers (1)
• Landslide deformation monitoring using point-like target offset tracking with multi-mode high-resolution TerraSAR-X data, Xuguo Shi, Lu Zhang, Timo Balz, Mingsheng Liao, ISPRS Journal of Photogrammetry and Remote Sensing, Vol. 105, 2015, pp.128-140.
• Potentials and limitations of SAR image simulators – A comparative study of three simulation approaches , Timo Balz, Horst Hammer, Stefan Auer, ISPRS Journal of Photogrammetry and Remote Sensing, Vol. 101, 2015, pp.102-109.
• A Novel Fast Approach for SAR Tomography: Two-Step Iterative Shrinkage /Thresholding, Lianhuan Wei, Timo Balz, Lu Zhang, Mingsheng Liao, IEEE Geoscience and Remote Sensing Letters, Vol. 12, Issue 6, 2015, pp.1377-1381.
• Compressive Sensing in High-resolution 3D SAR Tomography of Urban Scenarios, Mingsheng Liao, Lianhuan Wei, Ziyun Wang, Timo Balz, Lu Zhang, Journal of Radars (in Chinese), Vol. 4, Issue 2, 2015, pp.123–129.
Recent Publications
Journal Papers (2)
• Fusion of high-resolution DEMs derived from COSMO-SkyMed and TerraSAR-X InSAR datasets, Houjun Jiang, Lu Zhang, Yong Wang, Mingsheng Liao, Journal of Geodesy, Vol. 88, Issue 6, 2014, pp.587-599.
• Deformation monitoring of slow-moving landslide with L- and C-band SAR interferometry, Xuguo Shi, Lu Zhang, Mingsheng Liao, Timo Balz, Remote Sensing Letters, Vol. 5, Issue 11, 2014, pp.951-960.
• Expressway Deformation Mapping Using High Resolution TerraSAR-X Images, Xuguo Shi, Mingsheng Liao, Teng Wang, Lu Zhang, Wei Shan, Chunjiao Wang, Remote Sensing Letters, Vol. 5, Issue 2, 2014, pp.194-203.
• TerraSAR-X StripMap Data Interpretation of Complex Urban Scenarios with 3D SAR Tomography, Lianhuan Wei, Timo Balz, Mingsheng Liao, Lu Zhang, Journal of Sensors, Vol. 2014, Article ID 386753, 2014.
Recent Publications
Book Chapter: Monitoring Landslide Activities in the Three Gorges Area with Multi-frequency Satellite SAR Data Sets, Lu Zhang, Mingsheng Liao, Timo Balz, Xuguo Shi and Yanan Jiang, in Modern Technologies for Landslide Monitoring and Prediction, Edited by Marco Scaioni, Springer-Verlag Berlin Heidelberg 2015.
Recent Publications
This book chapter summarized our researches in the Three Gorges area during Dragon 2&3
Research Activities and Results
(May 2014 – May 2015)
Monitoring ground subsidence in Shanghai
PART I
Presented by Mingsheng Liao
M
S1
S2
S3
S4
S5
S6
S7
Multi-temporal imaging
Image stack
Subsidence Vel.
From conventional D-InSAR to PS-InSAR
Coverage of TSX data stacks in Shanghai
Downtown
Pudong New District
2009.10-2010.10 TSX result compared with levelling data (18 TSX images)
2010 subsidence map from leveling data
2010 subsidence result from TerraSAR-X
Highly consistent between two results
Hongkou
Become stable
Meilong
2012 subsidence map from leveling data
2012 subsidence result from TerraSAR-X
Highly consistent between two results
20011.10-2012.10 TSX result compared with levelling data (15 TSX images)
subsidence zones
Pudong Airport
Situan area
ZhangJiang
20013.9-2014.10 TSX result (26 images)
2014 subsidence data from TerraSAR-X
• Average error:1.79 mm
• STD: 1.59mm
Highly consistent between two results
20013.9-2014.12 TSX result compared with levelling data (26 TSX images)
Road network
ZhangJiang
Situan Town
2014 subsidence data from TerraSAR-X
Elevated road network
Elevated roads are more stable except a few sections within ZhangJiang settlement area
ZhangJiang
2014 subsidence data from TerraSAR-X
Driving force analysis of seriously subsiding roads
Metro Line 2
Metro Line 7
Inner Ring Elevated Road
Pujiang OCT Community
Export processing zone
Driving force analysis of seriously subsiding roads
Puxing Road
Subway network
ZhangJiang
Earlier sections are more stable than later sections
Subway network
Monitoring landslide stability in Three Gorges and NE China
PART II
Presented by Lu Zhang
Test sites in Three Gorges
Steep terrain Dense vegetation cover Complicated atmospheric
condition
Characteristics of Three Gorges area
HS: High-resolution Spotlight SM: StripMap
TerraSAR-X datasets over Three Gorges
SM data HS data
Orbit direction Descending Descending
Heading 190.7 189.6
Look angle(°) 24 39
Polarization VV HH
Azimuth spacing(m) 1.96 0.87 Range spacing(m) 0.91 0.45
Temporal coverage Jul 2008-May 2010 Jan 2009-Apr 2010
Basic parameters
The upper part of Fanjiaping landslide is very active. Deformation rate can reach 5cm/y. Time series deformation indicated Fanjiaping was moving during the
whole period.
Fanjiaping landslide motion detected by SBAS
Deformation rate estimated by PS-InSAR was unreasonably less than 1 cm/year compared with GPS.
Underestimation happened with sparse PS points identified. Shuping landslide is a south-north oriented slope.
Shuping landslide motion observed by PS-InSAR
– Based on SAR image matching at subpixel-level accuracy – Make use of pixels with high amplitude values, e.g. CRs – Avoid noisy measurements in vegetated areas – Without phase unwrapping – Can measure displacements at centimeter-level accuracy in
both line-of-sight direction (LOS) and azimuth directions * LOS ≈ vertical and east-west directions * Azimuth ≈ north-south direction
Suitable for measuring large displacements.
Point-like targets offset tracking (PTOT)
Corner Reflectors (CRs)
14 CRs erected on the Shuping landslide, the other 4 CRs in the surrounding
Displacements measured in azimuth and range directions can be as high as 1 meter and 0.8 meters respectively.
Observations coincide with the conclusions in Wang et al. 2008 that the eastern part of Shuping landslide is more active. Moving towards north direction into the Yangtze River.
Azimuth (m)
Range (m)
Displacements at Shuping measured by SM data (20080721-20100501)
CR6-Azimuth CR6-Range
CR15-Azimuth CR15-Range
Comparison between HS and SM measurements
HS
SM
Making full use of different look angles adopted by HS and SM acquisitions.
From 2D offset measurements to 3D displacement vector
HSazHSrg
SMazSMrg
d
d
d
d
N
E
V
DDD
V
N
E
azimuth
Estimation of 3D displacements
Horizontal
Vertical
Inverted 3D displacements at CRs (200902-201004)
Expressway stability analysis in permafrost area
Southern Border of permafrost
Lesser Khingan Mountain
Expressway
Study area
Workflow for linear infrastructure monitoring
High Resolution SAR Images
Interfrogram FormationDEM Subset Deformation
Subset
PT Detection
Phase Unwrapping
Unwrapped DEM Subset
Unwrapped Deformation
Subset
PT extraction
DEM Error and Linear Deformation RateInitial Estimation
Linear Deformation Rate Estimation
DEM Error Estimation
APS Estimation and RemovalNonlinear Deformation Estimation
Linear Deformation Rate and DEM Error
-Iterative
Operation
Time Series Deformation
-
- -
+
PT extraction
1. Only the most stable PT in each transection line along the linear infrastructure were analysed to convert into a one-dimensional problem.
2. One-dimensional phase unwrapping was carried out upon the PTs selected.
3. Interferograms were grouped into a DEM subset and a deformation subset to accurately separate the topographic phase and deformation signal from each other.
Deformations along Bei’an-Heihe Expressway
Height error Deformation map
Conclusion & Discussion
•Validations using leveling data showed the effectiveness of mapping large-area ground subsidence with TerraSAR-X data stacks covering Shanghai.
•Stability analyses of road networks in Shanghai revealed uneven spatial pattern of deformation with the Zhangjiang and Situan identified as two focus areas of subsidence.
•Driving force analysis suggested two major impact factors for road network subsidence: urbanization construction (e.g. subway tunnel excavation), seasonal temperature variation.
Conclusion & Discussion (1)
•Phase-based analyses of high-resolution SAR data can detect subtle surface deformation of slow-moving landslides in the Three Gorges area. By contrast, point-like target offset tracking is more suitable for mapping large deformation of fast-moving landslides.
•3D displacement vectors can be reconstructed by joint analysis of multi-orbit multi-aspect InSAR/offset tracking measurements.
•Experimental results in NE China suggest that deformation along linear infrastructures (expressway, railway, etc.) can be retrieved from time-series high-resolution SAR data using an improved SBAS method.
Conclusion & Discussion (2)