Spectral characteristics of infrared radiation from forest fires

Field experiments with man-made fires in a forest were conducted to verify fire warning products from satellite remote sensing techniques and to select more effective channels for producing these products. Pine branches and trunks as well as other woods were burned at a designated place in a pine-dominated forest to simulate wild forest fires when a satellite was passing over the sky. Infrared spectral irradiances, visible spectrum, brightness, and temperature were measured concurrently with satellite data at the ground using a medium and near-infrared MOMEM MR154 FT-Spectroradiometer, an infrared thermal imager, and a visible and near-infrared spectroradiometer (ASD FR). The measurements showed two emission peaks in middle infrared band that corresponded exceptionally to the combustion strength. One of the spikes at 4.17μm reflected the CO emission peak. The other peak spanned through the wavelengths of 4.34-4.76μm, which exhibited a much stronger response to the fire than the commonly used channel 3.5-4.0μm for fire monitoring in remote sensing. The results suggest that the wave band 4.34-4.76μm is probably more sensitive and more effective than the common-used channel for wild fire monitoring using satellite remote sensing techniques. However, the peak of this wavelength band drifted during the burning process, which should be taken into account in channel selection. This band is suitable to determine forest fires. Further studies are needed to use it for retrieving fire strength quantitatively.