2.4 Recording the movement of glaciers 
InSAR has been used to record the movement of glaciers and 
ice fields and has significantly advanced the study of glacier 
and ice flows and ice-sheet mass balance. By regularly imaging 
ice sheets over the Arctic, Antarctic, and Greenland, InSAR has 
contributed to building an unprecedented series of snapshots 
that document the short-term evolution of ice sheets, aiding in 
the understanding of their impact on sea-level change and 
global warming (Rignot and Thomas, 2002). 
2.5 Mapping water-level changes over wetlands 
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Figure 4. (a) C-band (wavelength of 5.7 cm) interferogram showing water-level changes over swamp forests over coastal 
Louisiana between May 22 and June 15, 2003 (Lu and Kwoun, 2007). The interferogram was produced from Radarsat-1 
images. The interferometric phase image is draped over the radar intensity image. Each fringe (full-color cycle) represents a 
2.8-cm change in range distance or a 3.1-cm change in water level, (b) A three-dimensional view of water-level changes 
derived from the InSAR image. 
Figure 5. Thickness of lava flows for the April 1997 eruption at Okmok Volcano, Alaska. The thickness is derived from the 
height difference between the pre-eruption and post-eruption DEMs that were constructed from repeat-pass InSAR images, (b) 
Lava thickness along a profile S-S, showing the thickest portion of the erupted lava flow reached nearly 50 m. 
Figure 6. (a) Rac 
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2.6 Constructing I 
InSAR can be use 
photogrammetric j