USGS - California Fire Response -Hyperspectral Remote Sensing
• Collection of airborne hyperspectral data (HyMap sensor)
• Conversion to reflectance using Radiative Transfer Ground Calibration (RTGC) method
• Spectral analysis to characterize and map ash and ash chemistry
Spectral Characteristics of HyMap
Spectral Range: ~ 400-2500 nmSpectral Sampling: ~ 15 nm (126 channels)Spectral Bandpass: ~ 15 nm
Spatial Swath: ~ 2 kmPixel Size: ~ 4 m
HyMap Data Coverage
• Harris Fire 11/15/2007
• Witch/ Poomacha
Fires 11/19/2007
During Hymap collection, field calibration sites were measured with a field spectrometer.
Orange pins = Ash sampling sites.
Content of Hyperspectral Data
• The shapes of spectral reflectance curves can be related to specific materials and chemical concentrations in materials
Example HyMap strip – Witch Fire
Results: AVIRIS Maps
GreenGreenVegetationVegetation
Mineral/AshMineral/Ash
Mineral-1Mineral-1mm
Mineral-2Mineral-2mm
Dry ConiferDry Conifer
Dry & GreenDry & GreenConiferConifer
Straw mattingStraw matting
Ash/CharcoalAsh/Charcoal
Straw mattingStraw matting & Green grass& Green grass
GreenGreenVegetationVegetation
Mineral/AshMineral/Ash
Mineral-1Mineral-1mm
Mineral-2Mineral-2mm
Dry ConiferDry Conifer
Dry & GreenDry & GreenConiferConifer
Straw mattingStraw matting
Ash/CharcoalAsh/Charcoal
Straw mattingStraw matting & Green grass& Green grass
