Change Detection Based on Persistent Scatterer Interferometry

Transcription

1 1 Institut für Photogrammetrie ifp Change Detection Based on Persistent Scatterer Interferometry Chia-Hsiang Yang, Uwe Soergel

2 2 ifp Contents Persistent Scatterer Interferometry Motivation and objectives Methodology Real data test Conclusions and future works

3 3 ifp Persistent Scatterer Interferometry (PSI) PS properties: 1. motion velocity (mm/year level) 2. height information 3. geographic position 4. temporal coherence 5. etc. Bing Maps image General point PS point (Hooper, 2006) TerraSAR-X image PS distribution

4 4 ifp Contents Persistent Scatterer Interferometry Motivation and objectives Methodology Real data test Conclusions and future works

5 ifp Motivation and Objectives Google 2010 Google 2014 Ratio image PSI result Our method PS points PS points Big change (BC) points 5

6 6 ifp Detection of Vanishing Substructures Break Period Front Image Set Complete Image Set PS points Vanishing BC (VBC) points

7 7 ifp Detection of Emerging Substructures Break Period Complete Image Set PS points Emerging BC (EBC) points Back Image Set

8 8 ifp Contents Persistent Scatterer Interferometry Motivation and objectives Methodology Real data test Conclusions and future works

9 9 ifp How to detect BC points automatically? Big Changes Vanishment and Emergence of PS points Temporal Coherence argmax Δh x & v x TC x 0, 1 R = 1 N 1 N 1 exp jj φ int O x φm int x int=1 Periodogram Search

10 10 ifp Change Index (CI) of Vanishment Break Period VBC points Front Image Set CI V x 1, +1 R Complete Image Set = TC F x TC C x CI of VBC point approaches 1 CI of PS point is close to 0

11 11 ifp Change Index (CI) of Emergence Break Period EBC points Back Image Set CI E x 1, +1 R Complete Image Set = TC B x TC C x CI of EBC point approaches 1 CI of PS point is close to 0

12 12 ifp Automatic Detection of BC Points Gaussian distribution + Large right tail (PS points) (BC points)

13 13 ifp Automatic Detection of BC Points Gaussian distribution + Large right tail (PS points) (BC points) Fitted Gaussian curve Change index threshold (3 sigma of fitted curve)

14 14 ifp Outlier Filtering Operator of sliding window Isolated PS, VBC, and EBC points Inconsistent points Single building (Google Earth image) Change detection image before filtering Change detection image after filtering

15 15 ifp Contents Persistent Scatterer Interferometry Motivation and objectives Methodology Real data test Conclusions and future works

16 - Study area (5km*5km) - Mean image (1m*1m) 16

17 ifp TerraSAR-X Images Break Period Front Image Set (16) Back Image Set (24) Complete Image Set (40) Acquisition Date 2010/10/ /08/ /08/ /02/ /11/ /10/ /09/ /03/ /01/ /12/ /09/ /03/ /02/ /01/ /10/ /05/ /03/ /02/ /10/ /05/ /03/ /02/ /11/ /06/ /06/ /06/ /12/ /07/ /06/ /07/ /12/ /08/ /07/ /07/ /01/ /08/ /08/ /08/ /01/ /09/04 Vanishment & Emergence ( ) 17

18 18 - PS points (steady buildings) - VBC points (vanishing buildings) - EBC points (emerging buildings)

19 19 North of Berlin Main Station Google Earth image (2010/09/12)

20 20 North of Berlin Main Station Google Earth image (2014/09/05)

21 21 - PS points (Steady buildings) - VBC points (Vanished buildings) - EBC points (Emerged buildings)

22 22 Monitoring Traffic Infrastructures Google Earth view (2010/09/12)

23 23 Monitoring Traffic Infrastructures Google Earth view (2014/09/05)

24 24 - PS points (Steady buildings) - VBC points (Vanished buildings) - EBC points (Emerged buildings)

25 25 Monitoring Business District Google Earth view (2010/09/12)

26 26 Monitoring Business District Google Earth view (2014/09/05)

27 27 - PS points (Steady buildings) - VBC points (Vanished buildings) - EBC points (Emerged buildings)

28 28 Monitoring Sports Playground Google Earth view (2010/09/12)

29 29 Monitoring Sports Playground Google Earth view (2014/09/05)

30 30 ifp Contents Persistent Scatterer Interferometry Motivation and objectives Methodology Real data test Conclusions and future works

31 ifp Conclusions Change Detection Based on PSI (CDPSI) PS points (steady objects) VBC points (vanishing objects) EBC points (emerging objects) Change index of pixel Indicator of big change Automatic thresholding Break period Time of big change Manual setting for specific interests Real data test Steady, vanishing, and emerging buildings in Berlin Monitoring of construction progress 31