Use of InSAR Satelite for the Disaster mitigation
Presented by Yo Fukushima, Tohoku University, Japan
Email; [email protected]
Disaster mitigation is one of the important tactics to reduce disaster damage and loss. We can use a satellite to mitigate disaster risk. Here is an example from the Nankai trough Synthetic aperture radar interferometry.
InSar Principle: How does it work?
InSAR satellite is located 700km of altitude from the earth surface and the radio frequency is transmitted at the right angle from the flying direction of the InSAR satellite. The beam of the satellite can cover 70km of land area to take the picture. The microwave from the InSAR satellite is transferred to the surface to get the image then it receives the reflected wave with a difference of the wave phase. Because the depends on the deformation the transmitted wave phase would be different then based on the two different wave phase a sharp distinct image can be prepared. The InSAR satellite is used to measure the surface deformation as a map of the digital elevation.
The InSAR satellite continuously travels until cover all the desired area. Every Path direction then combines to make a complete image of the area.
How to identify the rapture or Fault?
InSAR satellite sends the photos before the earthquake and after the earthquake then compare those data to decide the rapture and the fault of the earth surface.
Vertical and horizontal displacement can be identified by InSAR image
InSAR time series analysis:
Analysis of the captured photo before and after the earthquake we can see the clear change of the difference which indicates an earthquake event.
Another use of InSAR satellite;
- Tunnel monitoring
- Landslide monitoring
- Infrastructure or building monitoring
- Ice flow monitoring
- Volcanic activity monitoring
- And other naturals hazards which are generally not movable