I am frequently astonished at what remote sensing can accurately observe.
This month NASA reported a new technique that uses data from NASA’s Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) to monitor the health of forests.
AVIRIS provides data in optical wavelengths binned into 224 spectral bands, with about 30 m resolution (i.e., each pixel is 30×30 m.. This is high grade spectroscopy. How good is it? For comparison, the satellite borne LANDSAT has 8 bands and the more contemporary MODIS orbiters have 35 bands.
The report explains that analysis of the IR spectrum to detect damage to needles on evergreen trees due to bark beetle infestation. This damage is not apparent at first to the human eye, but makes the tree more susceptible to fire.
The result is a fairly detailed map of areas that have increased fire risk due to the otherwise hard to detect insect damage. (Not that any part of California isn’t prone to fire.)
At this point, there isn’t much that can be done other than document the damage, but accumulating this data over time may contribute to understanding the course of these infestations driven by heat and drought conditions,