Infrastructure monitoring using SAR interferometry

Transcription

1 Infrastructure monitoring using SAR interferometry Hossein Nahavandchi Roghayeh Shamshiri Norwegian University of Science and Technology (NTNU), Department of Civil and Environmental Engineering Geodesy and hydrography days, 2016

2 Observing the Earth ESA Copernicus program Copernicus is the most ambitious Earth observation program to date. It will provide accurate, timely and easily accessible information to improve the management of the environment, understand and mitigate the effects of climate change and ensure civil security. This initiative is headed by the European Commission (EC) in partnership with the European Space Agency (ESA). ESA is developing a new family of missions called Sentinels specifically for the operational needs of the Copernicus program. Each Sentinel mission is based on a constellation of two satellites to fulfil revisit and coverage requirements, providing robust datasets for Copernicus Services. These missions carry a range of technologies, such as radar and multi-spectral imaging instruments for land, ocean and atmospheric monitoring: Sentinel-1 is a polar-orbiting, all-weather, day-and-night radar imaging mission for land and ocean services. Sentinel-1A was launched on 3 April 2014 and Sentinel-1B on 25 April Both were taken into orbit on a Soyuz rocket from Europe's Spaceport in French Guiana. Courtesy: ESA 2

3 Observing the Earth ESA Copernicus program Sentinel-2 is a polar-orbiting, multispectral high-resolution imaging mission for land monitoring to provide, for example, imagery of vegetation, soil and water cover, inland waterways and coastal areas. Sentinel-2 can also deliver information for emergency services. Sentinel-2A was launched on 23 June 2015 and Sentinel-2B will follow in the second half of Sentinel-3 is a multi-instrument mission to measure sea-surface topography, sea- and land-surface temperature, ocean color and land color with high-end accuracy and reliability. The mission will support ocean forecasting systems, as well as environmental and climate monitoring. Sentinel-3A was launched on 16 February Sentinel-3B is scheduled for launch in Sentinel-4 is a payload devoted to atmospheric monitoring that will be embarked upon a Meteosat Third Generation-Sounder (MTG-S) satellite in geostationary orbit. Sentinel-5 is a payload that will monitor the atmosphere from polar orbit aboard a MetOp Second Generation satellite. Sentinel-5 Precursor satellite mission is being developed to reduce data gaps between Envisat, in particular the Sciamachy instrument, and the launch of Sentinel-5. This mission will be dedicated to atmospheric monitoring. Sentinel-6 carries a radar altimeter to measure global sea-surface height, primarily for operational oceanography and for climate studies. Courtesy: ESA 3

4 Copernicus: important for Norway and the Arctic

5 SENTINELS Sentinel-1 (radar, 5x20 m, 2014) Monitoring sea ice zones and the arctic environment, Surveillance of marine environment, Glacier drift, Ship detection,. Sentinel-2 (optical, 10 m, 2015) Images over Norway with high frequency, iceberg drift,. Sentinel-3 (Carry Radar altimeter, ocean and land, 2015) Sea level, Wave height, sea-surface temperature, sea ice, water clarity 5

6 Data forever 6

7 Copernicus Copernicus will give : Free of charge Near real time data forever 7

8 SAR Missions 8

9 Chinese SAR Satellite series 9

10 National Geohazards database National-scale imaging Geoscience Database 10

11 GNSS network Atmospheric Modelling 11

12 DTM 10-m resolution 12

13 (24 days) 13

14 Satellite data for everybody InSAR : Multi sensor/multi mission Multitrack Multi temporal Combined with other satellite systems 14

15 Radar Interferometry 15

16 Study areas Rafsanjan plain (southeast Iran) Lake Urmia causeway (northwest Iran) Trondheim (central Norway) 16

17 Methodology Small Baseline Subset (SBAS) Producing single-look differential interferograms Selecting the Slowly Decorrelating Filtered Phase (SDFP) pixels Three-dimensional phase unwrapping, and least-squares inversion 17

18 Land subsidence in agricultural areas near Rafsanjan Rafsanjan Rafsanjan 18

19 Motagh, Shamshiri, et al. 19 (engineering geology, reviewed with corrections)

20 20

21 Infrastructure monitoring 1998 Lake Urmia is one of the world s largest salt lakes, but it is shrinking in recent years

22 West Azerbaijan East Azerbaijan Embankments: Bridge:

23 Envisat ( ) Envisat ( ) ALOS ( ) TerraSAR-X ( ) A B Shamshiri, et al., JG,

24 Trondheim 24

25 TerraSAR-X results ( ) 25

26 Radarsat-2 results ( ) 26

27 Sentinel-1A results ( ) 27

28 Reasons of the difference Different imaging geometries The unit vector of the LOS direction in the coordinate system (east, north, up): (0.43, -0.1, 0.89) for TerraSAR-X (-0.33, -0.1, 0.94) for Radarsat-2 (-0.48, 0.1, 0.87) for Sentinel-1 Atmospheric artifacts Different displacement patterns in different years The LOS velocity maps alone are not useful in interpreting the results. 28

29 Time-series of displacement Converting the LOS of each observation to the vertical direction by ignoring the horizontal components Combining the vertical displacement of the three datasets, by fitting a polynomial to each of the time-series and calculating the shifts between datasets 29

30 Time-series of displacement Shamshiri, Nahavandchi, et al. Procedia Computer Science,

31 Deformation maps over roads and railways-terrasar-x 31

32 Thank you for your attention! 32