The Advanced Rapid Imaging and Analysis (ARIA) team at NASA's Jet Propulsion Laboratory in Pasadena, California, created these Damage Proxy Maps (DPMs) depicting areas in California likely damaged by the Woolsey and Camp Fires. They are derived from synthetic aperture radar (SAR) images from the Copernicus Sentinel-1 satellites, operated by the European Space Agency (ESA).
The pre-event images for the Woolsey Fire in Southern California (main image) were taken before the fire on Oct. 30, 2018 and the post-event image was acquired during the fire on Nov. 11, 2018. The map covers an area of 50 miles x 25 miles (80 km x 40 km), indicated with the big red polygon. Each pixel measures about 33 yards x 33 yards (30 m x 30 m). The color variation from yellow to red indicates increasingly more significant ground surface change.
The pre-event images for the Camp Fire in Northern California (Figure 1) were taken on Nov. 4, 2018 and the post-event images were acquired during the fire on Nov. 10, 2018. The map covers an area of 55 miles x 48 miles (88 km x 77 km). As in the previous image, each pixel measures about 33 yards x 33 yards (30 m x 30 m). The color variation from yellow to red indicates increasingly more significant ground surface change.
Preliminary validation for both maps was done by comparing approximate location data to Google's Crisismap. These damage proxy maps can be used as guidance to identify damaged areas with the understanding that they may be less reliable over vegetated areas including farmlands. 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.
Sentinel-1 data were accessed through the Copernicus Open Access Hub. The image contains modified Copernicus Sentinel data (2018), processed by ESA and analyzed by the NASA-JPL/Caltech ARIA team. This research was carried out at JPL funded by NASA.
For more information about ARIA, visit http://aria.jpl.nasa.gov.