Distinguishing between coniferous and deciduous forests using hyperspectral imagery

We test how well coniferous and deciduous forests can be distinguished using hyperspectral reflectance images. We find that within a given land cover, the average spectral angle and distance calculated from the mean spectrum ranges between 1-3 degrees and 0.2-0.4 du, respectively. These values are the lower limit on the ability of these metrics to separate land cover types. Our observations indicate that the major spectral difference between deciduous and coniferous forests is in the NIR plateau (750-1300 nm), a spectral region with high reflectance for green vegetation. Coniferous forests have NIR reflectances of approximately 0.2, while the reflectance for deciduous forests is 0.3 or greater. The shapes of the spectra, as measured by the spectral angle, are very similar. Individual pixel spectra, on the other hand, exhibit high variability, especially in the NIR plateau.