Monitoring of fog in Indo- Gangetic plain with INSAT- 3DR data & Channel differentiating method performance for Night time Fog

Abstract

Fog during winter season over Indo-Gangetic plains is very common and sometimes it creates hazardous situation and disrupts the life. Fog intensity and its spread forecast is challenging task. Most of the techniques available are mainly based on the remote sensing observation which is available on continuous bases and fills data gaps. To forecast precisely we need to validate the fog intensity or spatial extent during day and night. This work is mainly focuses on the night time fog monitoring with the help of satellite derived fog products. This product during night time is obtained through channel differencing (MIR-TIR1) of INSAT-3D /3R channels. Normal threshold was -2.5 degree C or K for fog pixels, but this work shows that this threshold does not hold good for entire IGP or Indian region, in the case of radiation fog. The different cases of the season 2020-21 (December-January) have been analyzed with different thresholds and found that other threshold ranges also significant for fog occurrences over the area.