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Using AVIRIS to assess hemlock abundance and early decline in the Catskills, New York [An article from: Remote Sensing of Environment]
Book Details
Author(s)J. Pontius, R. Hallett, M. Martin
PublisherElsevier
ISBN / ASINB000RR6R94
ISBN-13978B000RR6R97
AvailabilityAvailable for download now
MarketplaceUnited States 🇺🇸
Description
This digital document is a journal article from Remote Sensing of Environment, published by Elsevier in . The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description:
In order to aid land managers in monitoring and controlling the ongoing hemlock woolly adelgid outbreak, more accurate landscape scale tools are required to locate the hemlock resource, identify infestation and spot early decline. To this end, NASA's Airborne Visible Infra-red Imaging Spectrometer was flown over the infestation front in the Catskills region of New York during the summer of 2001. Mixture Tuned Matched Filtering in ENVI was used to ''unmix'' spectra and quantify the hemlock signature contribution to each pixel. The resulting percent hemlock basal area coverage correctly identified hemlock dominated pixels (>40% basal area) with 83% accuracy. Key wavelengths and health indices were examined to determine if a subset of wavelengths could accurately predict an 11-class decline rating system. A linear regression based on reflectance at a chlorophyll sensitive wavelength (R683 nm), coupled with a water band index (R970/R900), was able to predict decline with 85% accuracy. The extreme accuracy at the low (0-3) end of the range indicated that these wavelengths might be used to assess early decline, before visual symptoms are apparent in the field.
Description:
In order to aid land managers in monitoring and controlling the ongoing hemlock woolly adelgid outbreak, more accurate landscape scale tools are required to locate the hemlock resource, identify infestation and spot early decline. To this end, NASA's Airborne Visible Infra-red Imaging Spectrometer was flown over the infestation front in the Catskills region of New York during the summer of 2001. Mixture Tuned Matched Filtering in ENVI was used to ''unmix'' spectra and quantify the hemlock signature contribution to each pixel. The resulting percent hemlock basal area coverage correctly identified hemlock dominated pixels (>40% basal area) with 83% accuracy. Key wavelengths and health indices were examined to determine if a subset of wavelengths could accurately predict an 11-class decline rating system. A linear regression based on reflectance at a chlorophyll sensitive wavelength (R683 nm), coupled with a water band index (R970/R900), was able to predict decline with 85% accuracy. The extreme accuracy at the low (0-3) end of the range indicated that these wavelengths might be used to assess early decline, before visual symptoms are apparent in the field.
