Date of Images:

9/2/2020

Date of Next Image:

Unknown

Summary:

The Advanced Rapid Imaging and Analysis (ARIA) team at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, created this Damage Proxy Map (DPM) depicting areas of Northern California that are likely damaged (shown by red and yellow pixels) as a result of the recent wildfires. The map is derived from a stack of synthetic aperture radar (SAR) amplitude images (in HV polarization) acquired by JPL's UAVSAR sensor. The pre-event images were taken up to October 3, 2018 and the post-event image was acquired during the fire (September 3, 2020). Since the time span of the before and after images is long, this map can contain other changes occurred between the two dates, potentially due to previous fires or post-fire vegetation growth if any (e.g. areas affected by the 2017 Atlas Fire).

The color variation from yellow to red indicates increasingly more significant ground surface change. Preliminary validation was done by comparing to the Approximate fire location by the Copernicus Sentinel-2 optical imagery.

Suggested Use:

The color variation from yellow to red indicates increasingly more significant ground surface change. This damage proxy map should be used as guidance to identify damaged areas, and 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.

Note: These DPMs should be combined with known fire perimeters to ensure areas of change are due to the 2020 fires.

Satellite/Sensor:

UAVSAR airborne L-band synthetic aperture radar (SAR) aboard a NASA Gulfstream C-20A jet.

Resolution:

30 meters

Credits:

Analyzed by the NASA-JPL/Caltech ARIA team. This research was carried out at JPL funded by NASA Earth Applied Sciences Disasters Program.