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Tsunami At ACRS

In order to generate a viable response to natural disasters, the remote sensing industry needs to develop ways of tasking satellites much faster than it currently does. It also needs to improve revisit times and find ways to see through clouds.

Even more importantly, the industry needs a quicker mechanism for ordering and receiving data in emergency situations.

Of course, none of these is easy. To fix the first problem requires a lot of money; the second is subject to all sorts of international and domestic political issues. Don't expect it to happen soon.

This much seemed clear from a string of presentations to a session of the Asian Conference on Remote Sensing in Ha Noi last month. Speakers noted that during last December's tsunami, it took several days to get imagery of some of the worst affected regions. This made the job of emergency responders more difficult.

Leong Keong Kwoh was one of those most directly affected. As director of CRISP, the satellite downstation in Singapore, he was responsible for selecting which of the many satellites passing near the disaster area should be used.

As it turned out, there was no imagery available over Banda Aceh or the Thai west coast on either the 26th or 27th of December, due to cloud. On the 28th, data was obtained from both Space Imaging's Ikonos satellite and Spot Image's Spot-5.

In theory, it might have been possible to get data faster from MDA's Radarsat-1 spacecraft. This instrument is not affected by cloud or darkness, but with 30 metre resolution, it was of limited use for estimation of damage on the scale of individual buildings.

Presentations by Siti Yuhsniz from the University of Surrey, and Yasushi Arakawa from the Earth Remote Sensing Data Analysis Centre in Tokyo, confirmed that tasking remains a big problem.

ESRDAC will begin operating the PALSAR instrument on JAXA's ALOS when it is launched next year. Arakawa said the organisation is looking at streamlined tasking for disaster management.

Echoing Arakawa's concerns, a recent seminar at the Australian Centre for Remote Sensing heard that even when tasking requests are prioritised under current disaster management protocols, it could still take up to 12 hours to receive requested imagery.

Yuhsniz presented a paper to the conference on the international Disaster Mapping Constellation.

The DMC is a constellation of five identical satellites, built at the University of Surrey and owned by Thailand, the UK, Nigeria, Turkey and China.

Although several of the satellites are already in orbit, exactly how data will be ordered and distributed is still not clear. It is, however, generally acknowledged that to maximise the usefulness of the imagery, speed is of critical importance.

This may also prove difficult; all the satellites are under separate national control.