How does MODIS detect fires?
A hotspot/fire is detected by MODIS using data from the middle infrared and thermal infrared bands. These detections are produced using the same algorithm as the standard MODIS MOD14 fire and thermal anomalies product. The algorithm examines each pixel of the MODIS swath, and ultimately assigns to each one of the following classes: missing data, cloud, water, non-fire, fire, or unknown. In most cases, this thermal anomaly is a fire, but sometimes it is a volcanic eruption or the flare from a gas well. We have no way of knowing which it is based on the MODIS data alone.
