Abstract
The Sumatra earthquake struck South Asia on 26 December 2004 and triggered monstrous waves that turned into a tsunami hitting the ocean regions and caused the most severe natural disaster of recent decades. The devastating earthquake and tsunami changed the landscape of coastal areas in many countries around the whole Indian Ocean region. To provide real‐time information for rescue and rehabilitation plans, satellite images were applied to monitor and evaluate the damage over several devastated spots. The FORMOSAT‐2 satellite, which was launched on 21 May 2004 and operated by the National Space Organization, Taiwan, is uniquely designed to take timely and low‐cost black and white images daily with a resolution of 2 m and colour images of 8‐m resolution. FORMOSAT‐2 is expected to have many useful applications, such as natural‐disaster evaluation, land‐usage analysis, environmental monitoring, and coastal search and rescue. FORMOSAT‐2 successfully acquired several post‐tsunami images of the hazardous areas, both Puhket, Thailand and Banda Aceh, Indonesia on 28 December. A series of FORMOSAT‐2 satellite images were processed by geometric and radiometric correction, haze reduction, image enhancement, feature extraction, image classification, and image fusion to assess the damage over those devastated areas. FORMOSAT‐2 satellite images with a high‐temporal resolution and high‐spatial resolution were proved to be an efficient and useful information source for decision‐makers to make rescue and recovery plans, especially for some isolated islands hard to reach in time.
Acknowledgements
The authors thank the NSPO, Taiwan for kindly providing the FORMOSAT‐2 images. Sincere thanks also go to Mr Yen at NSPO and Mr Chen at NTNU for their help in the FORMOSAT‐2 image acquisition. Also, the constructive suggestions of the reviewers are appreciated.