Terra/ASTER urgent observation of earthquake and tsunami damaged area in north Sumatra, Indonesia and data analysis by using NDXI

摘要

ERSDAC has been responsible for the operation of ASTER (Advanced Spaceborne Thermal Emission & Reflection Radiometer) sensor loaded on Terra satellite ever since its launch in December 1999. One of the important functions of ASTER is "pointing" of up to 24 degrees. Pointing function is critical in carrying out an urgent observation, which enables data acquisition within three days, on the day of scheduling at the earliest. This function enabled ASTER to respond to various disasters since its launch. Acquired data has been utilized widely by various organizations and contributed to understand the damaged area and its condition. In the wake of Sumatra earthquake and tsunami, which triggered unprecedented destructions to coastal areas of Indian Ocean, ERSDAC has focused one month since 28th December 2004 for urgent observations of stricken areas, coordinating with other relevant agencies and organizations. Further, ERSDAC regularly monitors progress of rehabilitation at North Sumatra, which is close to the epicenter and thus suffered the severest damages. As a result of Terra/ASTER urgent observations, data of north Sumatra in Indonesia, Khaolak in Thailand, Sri Lanka, east India and other places were acquired successfully. Also, as a result of analysis with normalized vegetation, soil and water indices (NDXI) and other data, influence of tsunami in Banda Aceh was recognized to be conspicuous in northern area, while in southern area damages were restricted due to its narrow coastline. Damages of tsunami were identifiable by NDXI analysis of Banda Aceh. The observation attested to the efficacy of ASTER urgent observation, as well as NDXI analysis in case of understanding the overall damages incurred by water related disasters like tsunami.