annual results report terrain measurement (id....

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)