1/11/2017 - Robust Change Detection for Rapid Disaster Response using Synthetic Aperture Radar


12:00 PM - 12:50 PM
Geology 1707

Presented By:
Sang-Ho Yun - JPL


With increasing number of spaceborne Synthetic Aperture Radar (SAR) missions, satellite SAR data are becoming useful for humanitarian applications. We used SAR data from the Italian Space Agency’s COSMO-SkyMed satellites and the Japan Aerospace Exploration Agency’s ALOS-1/2 satellites to produce damage proxy maps (maps showing areas of potential damage) of various disaster events, including February 2011 M6.4 Christchurch earthquake in New Zealand, the 2011 Kirishima volcano eruption in Kyushu, Japan, the 2013 Super Typhoon Haiyan, and the 2013 Moore Tornado in Oklahoma, United States. More recently, we responded to the April 25, 2015 M7.8 Gorkha earthquake in Nepal and January 2016 Midwest Floods along the Mississippi river in the U.S. The Gorkha earthquake caused more than 9,000 fatalities and widespread building damage in central Nepal. Four days after the earthquake, one of the COSMO-SkyMed satellites acquired SAR data over Kathmandu area. Nine days after the earthquake, the ALOS-2 SAR satellite covered larger area. Using these radar observations, we rapidly produced damage proxy maps derived from temporal changes in Interferometric SAR (InSAR) coherence. These maps were qualitatively validated through comparison with independent damage analyses by National Geospatial-Intelligence Agency (NGA) and the UNITAR’s (United Nations Institute for Training and Research’s) Operational Satellite Applications Programme (UNOSAT), and based on our own visual inspection of DigitalGlobe’s WorldView optical pre- vs. post-event imagery. Our maps were quickly released to responding agencies and the public, and used for damage assessment, determining inspection/imaging priorities, and reconnaissance fieldwork. Future response will become more rapid and reliable thanks to more SAR missions with open data policy, including the European Space Agency’s Sentinel-1A mission currently in operation and NASA’s NISAR mission planned to be launched in 2020.

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