Fog Detection Using MODIS Data in the Yangtze River Delta

MODIS data provides good data resources in fog detection for its abundant bands and high resolution. The heavy fogs in the Yangtze River Delta during Dec. 20^th and 22^th in 2007 are detected by multi-spectral threshold method. According to the differences of the radiation features of the cloud, the fog and the land in the visible, middle infrared and far infrared bands, the multi-spectral method is developed to distinguish the fog from the cloud. The classification results, compared with the surface observation, indicate that this method has a good effect on fog detection.