Development and Evaluation of detection algorithm for FY-4 Geostationary Lightning Imager (GLI) measurement

The Feng-Yun-4 satellite (FY-4) is the second generation of China's geostationary meteorological satellite, it is scheduled launch in 2016. The FY-4 will carry the instrument of Geostationary Lightning Imager (GLI) which is the first lightning detection sensor on China's satellite. The GLI will be used to observe regional lightning activity in China. The GLI products will be used in forecasting and warning of convection precipitation, and studying of earth electric field. The GLI products generation algorithm has been developed based on filtering and clustering algorithm. It considered the Optical Transient Detector (OTD) and Lightning Image Sensor (LIS) clustering algorithm and could generate Level 2 lightning products (flashes, groups, events) from Level 1c GLI geo-located, time tagged lightning event data. During development of the GLI products generation algorithm, the data of ground-based lightning location network in China and LIS were combined and used to generate the simulated Level 1c proxy data. The details of simulated Level 1c proxy data will be provided in this paper. The proxy data was also used as input to the algorithm, and the output was evaluated using the measured data according to the fact that group is in correspondence with individual return strokes in a cloud-to-ground flash or individual high current discharges (K-changes) in a cloud flash. The speed and accuracy of algorithm will be further tested. It is believed that the GLI will make better analysis of characteristics of lightning distribution in China.