ARIA Damage Proxy Map: Japan, Typhoon Hagibis, Tokyo, 12 Oct 2019, v0.4

The Advanced Rapid Imaging and Analysis (ARIA) team at NASA's Jet Propulsion Laboratory and California Institute of Technology in Pasadena, California, in collaboration with the Earth Observatory of Singapore (EOS), created this Damage Proxy Map (DPM) depicting areas in Japan that are likely damaged (shown by red and yellow pixels) as a result of Typhoon Hagibis that made landfall as a Category 3 storm Saturday night (October 12) local time. The map was derived from Synthetic Aperture Radar (SAR) data acquired around 6am (local time) on October 13, 2019 by the Copernicus Sentinel-1 satellites operated by the European Space Agency (ESA). The pre-event images were taken before (October 7, 2019) and the post-event image was acquired within 12 hours after the hurricane's landfall. The map covers an area of 250 by 350 kilometers, indicated with the big red polygon. Each pixel measures about 30 meters across. The color variation from yellow to red indicates increasingly more significant ground surface change. Media reports provided anecdotal preliminary validation. This damage proxy map should be used as guidance to identify damaged areas, and may be less reliable over vegetated areas and flooded areas. For example, the scattered single colored pixels over vegetated areas may be false positives, and the lack of colored pixels over vegetated areas does not necessarily mean no damage. Copyright: Contains modified Copernicus Sentinel data (2019) processed by ESA, the ARIA team at NASA-JPL and Caltech, and EOS. This task was funded by NASA Disasters Program.

美国国家航空航天局（NASA）喷气推进实验室与加州帕萨迪纳加州理工学院的高级快速成像与分析（Advanced Rapid Imaging and Analysis, ARIA）团队，联合新加坡地球观测站（Earth Observatory of Singapore, EOS），制作了本损伤代理地图（Damage Proxy Map, DPM），用以呈现日本因海贝思台风（Typhoon Hagibis）登陆后可能存在的受损区域——图中以红色、黄色像素标记。该台风于当地时间10月12日周六晚间以3级风暴强度登陆。本地图基于欧洲空间局（European Space Agency, ESA）运营的哥白尼哨兵-1（Copernicus Sentinel-1）卫星于2019年10月13日当地时间清晨6时左右获取的合成孔径雷达（Synthetic Aperture Radar, SAR）数据生成。事件前影像采集于2019年10月7日，灾后影像则在台风登陆后12小时内完成获取。该地图覆盖范围为250千米×350千米，以大型红色多边形标注。每个像素的空间分辨率约为30米。色彩从黄色过渡至红色，对应地表变化程度的逐步加剧。媒体报道提供了初步的定性验证参考。本损伤代理地图仅可作为受损区域识别的辅助指引，在植被覆盖区域与洪涝区域的可靠性相对较低。例如，植被区域内零散的单色像素可能为误报结果，而植被区域未出现彩色像素也不代表完全无受损情况。本数据集包含由欧洲空间局处理的2019年哥白尼哨兵卫星修改数据，以及NASA喷气推进实验室、加州理工学院ARIA团队与新加坡地球观测站的相关成果。本项目由NASA灾害计划资助。