Shashi Kumar. Indian Institute of Remote Sensing. (Indian Space Research Organisation)

Transcription

1 Practical-1 SAR Image Interpretation Shashi Kumar Indian Institute of Remote Sensing (Indian Space Research Organisation) Department of Space, Government of India 04 Kalidas Road, Dehradun , U.K.

2 Data: TerraSAR-X High-Resolution SpotLight: India, Port of Visakhapatnam Location: India, Port of Visakhapatnam File format: GeoTiff Projection: UTM, WGS 84 Acquisition mode: SpotLight Polarization mode: Single Polarization channel: VV Angle of incidence: 41.9 Date: 12/10/2008 Look Direction: Right RADARSAT-2 C-band Fine Quad : Flevoland, The Netherlands Location: Flevoland, The Nethrlands File format: GeoTiff Projection: UTM, WGS 84 Acquisition mode: StripMap Polarization mode: Quad-pol Polarization channel: VH,HV,VH,VV Beam Mode: FQ9 Angle of incidence: 28.5 Date: 02/04/2008 Look Direction: Right Page 1 of 15

3 Task 1: RADARSAT-2 image of Flevoland, The Netherlands and the date of data collection was April 02, Figure 1(a): Backscatter Image RADARSAT-2 HH Polarization Figure 1(b): Backscatter Image RADARSAT-2 HV Polarization Page 2 of 15

4 Figure 2: Google Earth View of the imaged area Page 3 of 15

5 Figure 3(b): HV Polarization Figure 3(a): Google Earth View Figure 3(c): HH Polarization Figure 4(a): Google Earth Street View of Area-2 Page 4 of 15

6 Figure 4(c): HH Polarization Figure 4(b): Google Earth View Area 2 Figure 4(d): HV Polarization Question 1: What features can you observed from this SAR image? Question 2: What are the differences in backscatter responses from different features in like polarization (HH) and cross polarization (HV) images? Question 3: Are you able to identify the ships in the sea? Question 4: Locate buildings/urban-area in the SAR image Question 5: Why sea surface is appearing as black in SAR images Question 6: Can you identify the linear feature (feature 2 of Figure 1) in the SAR imagery (pointed with yellow arrow)? Page 5 of 15

7 Question 7: Which scattering will play important role in identification of the linear feature 2? Give logical reason. Effect of Speckle Filtering Figure 5(a): Backscatter Image RADARSAT-2 HV Polarization Page 6 of 15

8 3 4 Figure 5(b): Backscatter Image RADARSAT-2 HV Polarization after Speckle Filtering Question 8: Which image has a more serious problem with speckle noise? Question 9: What is the effect of speckle filtering? Question 10: Why do flat surfaces, such as the sea surface, agricultural fields and road appear very dark in the image? Question 11: Search the Flevoland city of The Netherlands in Google Earth and locate the area imaged in the given SAR image. Question 12: What are the features/objects shown in red circle (no.4) and yellow line (no. 3) in Figure 5(b)) Question 13: Are you able to see the same objects in the google earth optical image of same scale (shown in Figure 5(C))? Page 7 of 15

9 Figure 5(c): Google Earth Image of Flevoland, The Netherlands Page 8 of 15

10 Figure 6(a): Google Earth View of Area 3: Windmills Figure 6(b): HH Polarization Figure 6(c): HV Polarization Page 9 of 15

11 Figure 7(a): Power line suspension towers: Area 4 Red circle in Figure 5(b) Figure 7(b): HH Polarization Figure 7(c): HV Polarization Page 10 of 15

12 iirs Task2: TerraSAR-X image interpretation for Visakhapatnam, India 1 Figure 8(a): TerraSAR-X image of Visakhapatnam, India Page 11 of 15

13 Figure 8(b): Google Earth Image of Visakhapatnam, India Page 12 of 15

14 Figure 8(c): TerraSAR-X image of Visakhapatnam, India Page 13 of 15

15 backscatter responses of different features in TerraSAR image for Vishakhapattanam city, India? Figure 8(d): Google Earth Image of Visakhapatnam India Page 14 of 15

16 Question 14: What are backscatter responses of different features in TerraSAR image for Visakhapatnam city, India? Question 15: Try to identify the object in red circle in Figure 8 (a). Question 16: Can you identify tree shadow, railway station, railway bridges and stadium/playground in the SAR image (Figure 8 (a) and Figure 8 (c))? Question 17: Identify the location of Harbor (Fishing). Question 18: What will be the backscatter response from metallic objects? Question 19: Are you able to make analysis for the object no. 1 (represented by yellow line Figure 8 (a))? Compare the appearance of the same object in optical and SAR images. Page 15 of 15