Satellite-Aided Identification Of False Fire Spots Created By Cloud Reflection During Forest Fires

Forest fires are a severe threat to ecosystems,and effective ways to prevent and extinguish forest fires are constant concerns of forest managers.It has been found that remote sensing by satellites will greatly assist detection of forest fire across a wide region and at low costs.Although it earns growing attention,this technology will also create a number of false fire spots due to interferences with reflective clouds,clutters,and other heat sources on the surface.It is therefore necessary to detect and eliminate all false fire spots in a quick manner.Among the false spots,those created by clouds are the most difficult to identify because of wide distribution and volatility of clouds.This study targets at identification of false fire spots with the aid of satellite.It is based on the fact that most false spots result from cloud reflection,relies on MODIS(moderate-resolution imaging spectroradiometer),FY3(Feng-Yun Satellite No.3)and NOAA(National Oceanic and Atmospheric Administration)to collect data,and then obtains maps of fire spots and cloud distribution to identify false fire spots.The study results are also compared with fire records of Hunan Province of China.Mains steps of the study are:Satellite-aided mapping of fire spots:Based on the fact that every subject on the Earth will display a distinctive combination of reflectance,brightness and temperature,three maps of fire spots can be obtained with the aid of satellite and by means of MODIS(moderate-resolution imaging spectroradiometer),AVHRR(Advanced Very High Resolution Radiometer)and FY3(Feng-Yun Satellite No.3).Satellite-aided mapping of clouds:Based on the fact that clouds display higher reflectance and lower brightness and temperature than the underlying surface,three types of cloud map can be obtained with the aid of satellites and by means of MODIS(moderate-resolution imaging spectroradiometer),AVHRR(Advanced Very High Resolution Radiometer)and FY3(Feng-Yun Satellite No.3).Mapping of False Fire Spots:None-forest fire spots can be eliminated from the map of fire spots by overlaying the map with the map of forest distribution,and a map of suspected false fire spots can be obtained by further overlaying the resulted map with cloud maps.Meanwhile,the most probable false fire spots can be determined by collecting historical data about false fire spots created from cloud reflection and by setting up a regression function.Finally,a map of false fire spots can be obtained by comparing the set of suspected false fire spots and that of most probable false fire spots.Application:this research has collected LIB data offered by meteorological satellites for Hunan Province of China between 2015-2016,studied forest distribution and forest fire history of that province,and then created maps of false fire spots.A comparison of the maps with the forest fire history of that province showed that the maps had a high predictability.Research on the prediction of false fire spots with the aid of satellites is at its initial stage.This study managed to eliminate false fire spots by means of map overlays analysis andangle method.Comparison of study results with records showed that the method proposed in this study was able to predict false fire spots with high accuracy.