Images from various satellites

Satellite is the only means to ascertaining the comprehensive overview of the damages caused. Some satellites are suited to securing the overall situation, some for picking up the details, and the radar satellite allows for observation even through overcast. These diverse satellite technology all come together to provide an extensive data for a wide area.

Inundation assessment of the Tohoku coastal region from the wide-area satellite image

Some satellites, though with limited resolution performance, frequently record images across Japan. This wide-area image was taken around 10:30 on March 14th by the Terra satellite (U.S.). The flooded area is shown in light blue. You can see an enlarged version by clicking on each of the area.

Estimating the extent of inundation in the Tohoku Region using area-wide satellite image

Inundation assessment with the radar satellite image

The flooded area from the tsunami appears dark as radar wave bounces off the surface and does not send data back to the satellite. By extracting the dark area through an image processing technique, we were able to make an assessment of the extent of the inundation at the time. This radar image was taken with the RADARSAT at 05:38 on March 13. The red mark along the coastal line is considered to be the flooded area.

Estimation of the extent of inundation using radar satellite image

**Radar satellite images showing the detailed assessment of the affected area **

By studying the pre-quake visual data and the post-quake high resolution radar satellite images, we can identify the infrastructural damages in the area to a great detail. This photo was taken at 18:34 on March 12th, one day after the quake with the COSMO-Skymed satellite (Italy). As radars have the ability to detect images through the clouds, despite the poor weather which continued after the quake, they were able to quickly pick up on the extent of the damages in the area.

☆Damages in the city of Rikuzen-takata via radar satellite image (March 12)

OSMO-SkyMed Product cASI-Agenzia Spaziale Italiana 2011.

Pre-quake optical satellite image (2010)

☆Damages in the Ofunato city via radar satellite image (March 12)

COSMO-SkyMed Product cASI-Agenzia Spaziale Italiana 2011.

Pre-quake optical satellite image (2010)

Damages in Soma city via high resolution satellite images

The super high resolution satellite images can greatly reveal the details of the post-quake damages which cannot be identified on aerial photos. This image was taken at 10:34 on March 12th, just under 20 hours after the quake, from a 1km resolution over Soma city(Fukuoka. The images show the extent of the destruction and flood damages to houses as well as the spread of debris across the area. The pre-quake tide level is estimated at 0.2m below sea level.

☆Damages in Soma city via high resolution satellite images (false color)

Devastation in Soma City by satellite imagery (false color)

☆Damages in Soma city via high resolution satellite images (true color)

Satellite imagery (true color) of devastation in Soma City

**Damages to cities, Rikuzen-takata and Ofunato, via super high resolution satellite images **

This was taken just under two days after the quake at 10:15 on March 13 at a ground resolution of about 50cm by GeoEye satellite. It shows the level of devastation to a great detail such as the flood damages, washed away houses, and the vast amount of debris spread across a wide area. Based on the pre-quake tide level chart, the tide level at this time was about sea level.

1. Takekoma, Rikuzen-takaka 2. Rikuzen-takata city center 3. Otomo, Rikuzen-takaka 4. Hirota area, Rikuzen-takata 5. Ofunato city center 6. Ofunato port breakwater, Ofunato

Toward Sound Recovery: Monitoring of Debris Distribution using High-resolution Satellite Imagery

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