Monitoring of Green Tide Under Cloud Based on GOCI-II Data

The outbreak of green tides has caused various degrees of damage to coastal areas, and the extraction of green tides based on optical data is vulnerable to cloud. Based on GOCI
$-\Vert$
(Geostationary Ocean Color Imager -
$\Vert)$
data, this paper proposes a multi-band threshold combination method for the extraction of green tide under clouds by analyzing the green tide sensitive wavebands. The monitoring results of this algorithm are compared with the monitoring results two existing algorithms (NDVI (normalized difference vegetation index) threshold method and IGAG algorithm), and it is found that the multi-band threshold combination method has better results in extracting green tide under clouds, and can obtain more detailed and comprehensive green tide information. Compared with visual interpretation results, the extraction accuracy of thin cloud and thick cloud is 80% and 50%, respectively. The extraction accuracy is both due to NDVI and IGAG methods, indicating that the multi-band threshold combination method has higher accuracy.