20251022 10321700 1.0 TRUE 150000000 5000 ItemDescription Sentinel-2 Normalized Burn Ratio Difference (dNBR) for the Southern California Wildfires January 2025. <div style='text-align:Left;'><div><div>Date of Image(s):12/18/2024; UTC: 1837091/12/25; UTC: 183731Summary:These pre-fire and post-fire images pair were analyzed for normalized burn ratio (NBR). The input imagers were generated from the ESA’s Sentinel-2’s Multi-Spectral imager. They were created from the Level 2A products which have been atmospherically corrected and orthorectified.NBR is defined mathematically as (NIR – SWIR)/(NIR + SWIR) where NIR is near-infrared and SWIR is short-wave infrared. For Sentinel 2, NIR = Band 8 and SWIR = Band 12. Using these definitions, the 20-meter resolution Band 8 and Band 12 images were used to generate these products. Sentinel-2 NBR methods: https://custom-scripts.sentinel-hub.com/custom-scripts/sentinel-2/nbr/Finally dNBR is simply the difference between the pre-fire NBR and the post-fire NBR. Thus, we calculated dNBR as dNBR = NBR(12/18/2024) - NBR(01/12/2025).Suggested Use:NBR is commonly used as a proxy to indicate areas which have charred vegetation. Darker areas (more negative values) in the NBR image more strongly represent the presence of burned vegetation. Since the dNBR considers the condition of the scene before the fire occurred, the resulting value has been used as a proxy for burn severity. More positive values in the dNBR analysis represent a proxy for greater burn severity. Negative values in dNBR represent a re-greening of or growth of vegetation in between pre and post imagery.The use of this dNBR product as a quantitative metric of burn severity of the Los Angeles Fires at the time of posting this dataset should be strongly caveated. This is due to several dNBR Limitations:The spectral band selections used in the NBR and dNBR calculations, and the implication of changes observed following fire in those wavelengths, primarily pertain to how vegetation spectral signatures change in NIR and SWIR wavelengths following charring. Because of this, dNBR may not accurately describe burned surfaces that are not vegetation (e.g. human built infrastructure).This dataset has not been validated by independent burn severity assessments.The degree to which dNBR is accurately determined depends on careful selection of pre and post event imagery. An effort was made to use the highest quality imagery (i.e. cloud free) with the shortest time difference possible in the image pair; however, it is unknown at the time of this posting how selection of different pre/post image pairs could affect the derived dNBR values.Satellite/Sensor:ESA Copernicus Sentinel-2Resolution:20 m in infrared bandsCredits:Copernicus Sentinel-2 data was downloaded from the Sentinel-2 data explorer (https://dataspace.copernicus.eu/explore-data/data-collections/sentinel-data/sentinel-2)Data processed by Kyle Kabasares (ARC; kyle.k.kabasares@nasa.gov)References:Normalize Burn Ratio theory: <a href='https://un-spider.org/advisory-support/recommended-practices/recommended-practice-burn-severity/in-detail/normalized-burn-ratio' style='text-decoration:underline;' target='_blank'>https://un-spider.org/advisory-support/recommended-practices/recommended-practice-burn-severity/in-detail/normalized-burn-ratio</a>Service URL:<a href='https://gis.earthdata.nasa.gov/portal/home/item.html?id=3bc872886af24b799acd2ef881691a6a' target='_blank'>https://gis.earthdata.nasa.gov/portal/home/item.html?id=3bc872886af24b799acd2ef881691a6a</a> WMS Endpoint:<a href='https://gis.earthdata.nasa.gov/gis05/services/DISASTERS_202501_FIRE_CA/SENTINEL2_DNBR/ImageServer/WMSServer' target='_blank'>https://gis.earthdata.nasa.gov/gis05/services/DISASTERS_202501_FIRE_CA/SENTINEL2_DNBR/ImageServer/WMSServer</a></div></div></div> Copernicus Sentinel-2, Kyle Kabasares (ARC; kyle.k.kabasares@nasa.gov) Sentinel-2 Normalized Burn Ratio Difference (dNBR) for the Southern California Wildfires, January 2025 NBR dNBR Normalized Burn Ratio California Los Angeles Wildfires <div style='text-align:Left;'><div>The use of this dNBR product as a quantitative metric of burn severity of the Los Angeles Fires at the time of posting this dataset should be strongly caveated. This is due to several dNBR Limitations:The spectral band selections used in the NBR and dNBR calculations, and the implication of changes observed following fire in those wavelengths, primarily pertain to how vegetation spectral signatures change in NIR and SWIR wavelengths following charring. Because of this, dNBR may not accurately describe burned surfaces that are not vegetation (e.g. human built infrastructure).This dataset has not been validated by independent burn severity assessments.The degree to which dNBR is accurately determined depends on careful selection of pre and post event imagery. An effort was made to use the highest quality imagery (i.e. cloud free) with the shortest time difference possible in the image pair; however, it is unknown at the time of this posting how selection of different pre/post image pairs could affect the derived dNBR values.NASA data and products are freely available to federal, state, public, non-profit and commercial users. This information can be experimental- or research-grade data products and may not be appropriate for operational use. These NASA data products, services, and the Disasters Mapping Portal are intended to aid decision makers and enhance situational awareness, but these data are not guaranteed to be consistently available or routinely updated.</div></div> 20251023