时间序列MODIS数据赤潮信息提取研究

MODIS数据在赤潮遥感监测中发挥着重要作用,其较高的光谱分辨率和时间分辨率在赤潮监测中有较大优势。本文利用2008年5月份多个时相MODIS数据对东海赤潮进行了研究,分别采用叶绿素浓度固定阈值法、月平均值差值法和海温及多光谱综合法对水体异常信息进行提取分析。通过对提取图像及其统计数据比较分析发现,固定阈值法所提取的信息会随阈值设置不同而变化,海温及多光谱综合法在有赤潮发生时提取信息与其他方法较一致,在未发生赤潮时则会发生多提误判。叶绿素浓度月平均值差值法所提取的时间序列赤潮信息则最客观地反映了赤潮变化趋势,能够很好地用于东海赤潮遥感监测。

Remote Sensing Detection of Red Tide by Time-series MODIS Data

MODIS data with high spectral and time resolution plays a significant role in the red tide monitoring.In this paper,MODIS images in time series in May,2008 were acquired to extract potential red tides over the East China Sea,using Chlorophyll Concentration Fixed Threshold Method(CCFTM),Monthly Mean Difference Method(MMDM),and Sea Surface Temperature Integrated Method(SSTIM) with multi-spectral data respectively.Extracted area of CCFTM varied with the threshold and SSTIM was consistent with other methods,but brought the misjudgments when there was no red tide.The extraction results show that CCFTM method achieved the most objective result in time-series images which well exhibited the red tide trend and can be effectively applied in red tide monitoring of the East China Sea.