Method for estimating sea surface green tide coverage area under MODIS image cloud

Abstract

The invention discloses a method for estimating the sea surface green tide coverage area under MODIS image cloud, and the method comprises the following steps: carrying out the preprocessing of remotesensing image data, obtaining a water body remote sensing reflectivity image and a DVI image map of a research sea area, extracting green tide information and surrounding cloud information covered bygreen tide, determining a cloud pixel with green tide distribution around by utilizing the rectangular frame, assuming that the cloud pixel is a central pixel and the same rectangular frame with green tide at the periphery is an adjacent pixel, calculating a cloud coverage area in the central pixel and a green tide coverage area in each adjacent pixel, calculating the mean value of the green tidecoverage ratios in the adjacent pixels, taking the mean value as a central pixel value, and taking the product of the cloud coverage area in the central pixel and the central pixel value as the coverage area of the green tide on the sea surface under the cloud. According to the method disclosed by the invention, the green tide coverage area of the sea surface under the MODIS image cloud can be better estimated, the influence of the cloud on the optical image on green tide area estimation is reduced, and technical support can be provided for quantitative analysis and research of green tide.

Description

technical field [0001] The invention relates to the technical field of marine monitoring, in particular to a method for estimating the coverage area of ​​green tides on the sea surface under clouds of MODIS images. Background technique [0002] In recent years, the green tide and gold tide disasters caused by the rapid reproduction and accumulation of floating macroalgae have increased significantly in the global ocean and become a global marine ecological problem. Since 2007, the Yellow Sea has experienced the world's largest cross-regional green tide disaster every summer, which has caused serious ecological environment and socio-economic impacts, and has attracted widespread attention from scholars and the public. In many studies, satellite data has played an important role due to its multi-view, multi-scale, and large-scale advantages. Through remote sensing data, the origin and early development process of the green tide are gradually clear: The green tide in the South...

AI Technical Summary

Problems solved by technology

However, the noise signal in microwave remote sensing data has a significant impact on the interpretation of Enteromorpha, and the method of using microwave remote sensing to monitor green tide is still in its infancy

[0004] Therefore, most of the current studies on the area and biomass of green tides first pick up the clouds and then analyze them, without considering whether there is floating macroalgae under the clouds, which will increase the gap between the estimated green tide biomass and the actual biomass. difference

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