UAVSAR Imagery Classification after Hurricane Milton, October 2024

Dates of Images: 10/11/2024, 10/12/2024, 10/13/2024, 10/14/2024 Date of Next Image: None Expected Summary: These UAVSAR false color RGB images provide a unique look at the Earth's surface that can be used for identifying flooding and inundation under tree canopy. The overlay of the intensities of these three polarization channels allows user to visually classify a scene by its backscattering mechanism, such as surface scattering (strong HH and VV return), volume scattering (strong HV return) and double-bounce scattering (strong HH return). Areas dominated by green (HV) intensity are typically vegetated areas. Areas dominated by shades of pink (HH+HV) intensity are typically inundated forests or vegetated fields. Black and dark grey areas are usually smooth surface (roads, open water, smooth bare ground) where there is very little radar backscatter. Suggested Use: The polarimetric color composite is well suited for identifying inundation under tree canopies. This product is especially useful in mapping inundation extent in regions covered with vegetation where the ground is not visible in optical imagery. RGB Images: Open water can be seen as dark blue/black, areas with inundation under tree canopy can be seen in pink-like colors. Satellite/Sensor: UAVSAR airborne L-band synthetic aperture radar (SAR) aboard a NASA Gulfstream C-20A jet. Resolution: 10 meters Credits: UAVSAR data courtesy of NASA/JPL-Caltech Service URL: https://gis.earthdata.nasa.gov/portal/home/item.html?id=912fb5f69b694d1a89914551a09bb27b WMS: https://gis.earthdata.nasa.gov/portal/services/DISASTERS_202410_HURRICANE_MILTON/2428_uavsar_rgb/ImageServer/WMSServer

Dates of Images: 10/11/2024, 10/12/2024, 10/13/2024, 10/14/2024 Date of Next Image: None Expected Summary: These UAVSAR false color RGB images provide a unique look at the Earth's surface that can be used for identifying flooding and inundation under tree canopy. The overlay of the intensities of these three polarization channels allows user to visually classify a scene by its backscattering mechanism, such as surface scattering (strong HH and VV return), volume scattering (strong HV return) and double-bounce scattering (strong HH return). Areas dominated by green (HV) intensity are typically vegetated areas. Areas dominated by shades of pink (HH+HV) intensity are typically inundated forests or vegetated fields. Black and dark grey areas are usually smooth surface (roads, open water, smooth bare ground) where there is very little radar backscatter. Suggested Use: The polarimetric color composite is well suited for identifying inundation under tree canopies. This product is especially useful in mapping inundation extent in regions covered with vegetation where the ground is not visible in optical imagery. RGB Images: Open water can be seen as dark blue/black, areas with inundation under tree canopy can be seen in pink-like colors. Classified Images: Blue areas are open water (some roads may also be misclassified as blue) Light Blue/Cyan areas with flooding beneath vegetation and the tree canopy Pink areas are potentially flooded areas with low confidence due to being more developed locations Satellite/Sensor: UAVSAR airborne L-band synthetic aperture radar (SAR) aboard a NASA Gulfstream C-20A jet. Resolution: 10 meters Credits: UAVSAR data courtesy of NASA/JPL-Caltech Esri REST Endpoint: https://gis.earthdata.nasa.gov/portal/rest/services/DISASTERS_202410_HURRICANE_MILTON/UAVSAR/ImageServer

Dates of Images: 10/11/2024, 10/12/2024, 10/13/2024, 10/14/2024 Date of Next Image: None Expected Summary: These UAVSAR false color RGB images provide a unique look at the Earth's surface that can be used for identifying flooding and inundation under tree canopy. The overlay of the intensities of these three polarization channels allows user to visually classify a scene by its backscattering mechanism, such as surface scattering (strong HH and VV return), volume scattering (strong HV return) and double-bounce scattering (strong HH return). Areas dominated by green (HV) intensity are typically vegetated areas. Areas dominated by shades of pink (HH+HV) intensity are typically inundated forests or vegetated fields. Black and dark grey areas are usually smooth surface (roads, open water, smooth bare ground) where there is very little radar backscatter. Suggested Use: The polarimetric color composite is well suited for identifying inundation under tree canopies. This product is especially useful in mapping inundation extent in regions covered with vegetation where the ground is not visible in optical imagery. RGB Images: Open water can be seen as dark blue/black, areas with inundation under tree canopy can be seen in pink-like colors. Satellite/Sensor: UAVSAR airborne L-band synthetic aperture radar (SAR) aboard a NASA Gulfstream C-20A jet. Resolution: 10 meters Credits: UAVSAR data courtesy of NASA/JPL-Caltech Esri REST Endpoint:

Dates of Images: July 9, 2025 Date of Next Image: None Expected Summary: These maps show the results of a machine learning classification applied to UAVSAR data to identify open water flooding and inundation under tree canopy.  Colored areas in the image show detected flooding, where the color shows the type of landcover which was flooded (see legend below).  Non-flooded areas are transparent.  The classification uses a U-Net machine learning algorithm which was trained using UAVSAR data from previous flood events.  UAVSAR provides polarimetric synthetic aperture radar data from which different types of scattering mechanisms can be observed, which provides information on the type of flooding.  For example, flooding underneath vegetation produces strong double-bounce scattering from the water surface and tree trunks.  However, strong double-bounce scattering from urban areas aligned with the radar viewing direction, such as in Austin, TX, can produce erroneous classifications.  Non-flooded vegetation is generally dominated by volume scattering from the forest canopy.  In comparison, open water flooding exhibits weak radar returns in all polarizations. Suggested Use: Classified Images: Blue   = Open Water Red    = Flooded Developed Green  = Flooded Vegetation Orange = Flooded Crop Satellite/Sensor: UAVSAR airborne L-band synthetic aperture radar (SAR) aboard a NASA Gulfstream C-20A jet. Resolution: 10 meters Credits: UAVSAR data courtesy of NASA/JPL-Caltech Esri REST Endpoint: See URL section on right side of the page WMS Endpoint: https://maps.disasters.nasa.gov/ags03/services/texas_flood_202507/uavsar/MapServer/WMSServer Data Download: https://uavsar.jpl.nasa.gov/cgi-bin/download-files.pl

Dates of Images: July 9, 2025 Date of Next Image: None Expected Summary: These maps show the results of a machine learning classification applied to UAVSAR data to identify open water flooding and inundation under tree canopy.  Colored areas in the image show detected flooding, where the color shows the type of landcover which was flooded (see legend below).  Non-flooded areas are transparent.  The classification uses a U-Net machine learning algorithm which was trained using UAVSAR data from previous flood events.  UAVSAR provides polarimetric synthetic aperture radar data from which different types of scattering mechanisms can be observed, which provides information on the type of flooding.  For example, flooding underneath vegetation produces strong double-bounce scattering from the water surface and tree trunks.  However, strong double-bounce scattering from urban areas aligned with the radar viewing direction, such as in Austin, TX, can produce erroneous classifications.  Non-flooded vegetation is generally dominated by volume scattering from the forest canopy.  In comparison, open water flooding exhibits weak radar returns in all polarizations. Suggested Use: Classified Images: Blue   = Open Water Yellow = Flooded Developed Green  = Flooded Vegetation Orange = Flooded Crop Satellite/Sensor: UAVSAR airborne L-band synthetic aperture radar (SAR) aboard a NASA Gulfstream C-20A jet. Resolution: 10 meters Credits: UAVSAR data courtesy of NASA/JPL-Caltech Esri REST Endpoint: See URL section on right side of the page WMS Endpoint: https://gis.earthdata.nasa.gov/portal/services/DISASTERS_202507_FLOOD_TX/202507_UAVSAR/MapServer/WMSServer Data Download: https://uavsar.jpl.nasa.gov/cgi-bin/download-files.pl

Dates of Images: Pre-Event: 10/3/2024, 10/8/2024 Post-Event: 10/11/2024, 10/20/2024 Date of Next Image: Varies by region, typically 12 days since previous pass. Set time slider to most recent interval and click on area of interest to identify date of last pass. Summary: The Alaska Satellite Facility has developed false color Red, Green, Blue (RGB) and Radiometrically Terrain-Correct (RTC) composites and surface water extent products of the Sentinel-1A/B Synthetic Aperture Radar (SAR) instrument which assigns the co- and cross-polarization information to a channel in the composite. When used to support a flooding event, areas in blue denotes water present at the time of the satellite overpass before or after the start of the flooding event. Sentinel-1 RGB Decomposition of RTC VV and VH imagery over United States coastlines. Blue areas have low returns in VV and VH (smooth surfaces such as calm water, but also frozen/crusted soil or dry sand), Green areas have high returns in VH (volume scatterers such as vegetation or some types of snow/ice), and Red areas have relatively high VV returns and relatively low VH returns (such as urban or sparsely vegetated areas). Suggested Use: In this image, water appears in blue, vegetated areas in shades of green and urban areas in bright orange. It is recommended to use this product with ancillary information to derive flooded areas. Post-event data is classified from the above imagery shows water that is detected by the sensor with different colors indicating different land cover/land use classifications from CDL that appear to have water and are potentially flooded. Blue (1): Known Water Red (2): Flooded Developed Green (3): Flooded Vegetation Orange (4): Flooded Cropland/Grassland Satellite/Sensor: Synthetic Aperture Radar on European Space Agency's (ESA) Copernicus Sentinel-1A satellite Resolution: 20 meters Service URL: https://gis.earthdata.nasa.gov/portal/home/item.html?id=d5280404a6c948d7a5ad0bfdcba4883e WMS: https://gis.earthdata.nasa.gov/portal/services/DISASTERS_202410_HURRICANE_MILTON/2428_sentinel1/ImageServer/WMSServer