In order to produce a calibrated hyperspectral image, each individual image
must be scaled by a calibration factor. The calibration factors were determined
by comparing the image data at a reference location to direct radiometric
measurements (PhotoResearch PR-650) of the light coming from this location.
For the BearFruit1B and BearFruit1Y images, the reference location is labeled
"R" in the image at right. When we acquired the BearFruit1Y image,
we also measured spectra from three additional image regions, labeled "P"
(pink), "T" (table), and "B" (box). The three plots
on this page compare these additional spectra to the spectra derived from
the BearFruit1Y image at the same locations. The agreement is generally
good, although there are small deviations at 440 nm and 490 nm.