摘要
遥感技术已经成为赤潮监测的重要手段之一,目前,国内外已有多项应用遥感技术对赤潮成功监测的实例。现有的监测方法主要依据海水水色图、叶绿素浓度图和海洋表面温度图,但这些专题图在反应赤潮发生情况时都不可避免地存在一些局限性。而基于光谱曲线特性和波谱角分类的赤潮监测方法不但可以对各种不同赤潮监测均有很好的可靠性,同时还具有可以识别赤潮优势种等诸多优点。该文章对这种监测方法的原理和过程进行了详细的阐述,并使用实际数据进行了实验分析。
Remote sensing technique has become one of the most important means of red tide detection. Now, there have been a number of successful applications of red tide detections using remote sensing technology in the world. The present detecting technology basically based on the true color images of the ocean, chlorophyll a （CHL-a） maps and sea surface temperature （SST） maps, however, these methods all have some limitations. In this paper, the author suggested a process based on the spectral signature and spectral angle mapping （SAM） method to detect red tides. As preprocess, minimum noise transform （MNF） and pixel purity index （PPD should be done to collect the end-members. Then, we can select the end-members in the n-dimensional visualization of ENVI software. By examining the end-members＇ spectral signature, people can tell whether it： is the red tide pixel or not, even which dominant species are as well with a complete spectral libraries. Finally, with the SAM method, red tide class can be highlighted. It is also very convenient to do the area calculation and change detection after this kind of classification, and with the high temporal resolution of MODIS, it is possible for us to analyze the relationship of the probable influencing factors of red tides and the change of red tide area based on the change detection. That will he helpful to realize the red tide prediction which could minimize the losses caused by red tides.
出处
《遥感信息》
CSCD
2009年第4期50-54,61,共6页
Remote Sensing Information
基金
2008国家大学生创新实验项目(081048636)
