马尾藻遥感信息提取

Sargassum Extraction Using Remote Sensing Technology

以Landsat数据为基础,分析马尾藻的图像和波谱特征,对比分析单波段提取法、双波段比值法、双波段差值法和归一化植被指数法对马尾藻信息的提取结果,并利用IKONOS数据来验证4种方法的提取精度。结果表明:马尾藻在Landsat真彩色(TM3、TM2、TM1)和假彩色(TM4、TM3、TM1)合成图上均呈黄色,其生长边界在假彩色合成图上更为清晰。马尾藻水体与非藻类水体在TM4的差异最大,在TM3也存在细小差异,单波段提取法(TM4)、双波段比值法(TM4/TM3)、双波段差值法(TM4-TM3)和归一化植被指数法((TM4-TM3)/(TM4+TM3))都可以从自然水体中提取出马尾藻信息,与IKONOS的提取结果相比,归一化植被指数法的提取精度最高。

Abundant Sargassum in the coastline of northern South China Sea present great ecological role and are worthy of exploration. Study on the method of extracting Sargassurn using remote sensing technology is a fundamental work to investigate resource and constitute the protection and exploitation rule. In this paper,spectrum and image characters of Sargassum are studied. Four methods,single band,dual bands ratio,dual band difference and normalized differential vegetation index are used to extract Sar-gassum. The precision of extraction result is verified by IKONOS data. The results show that both in true color （TC） and false color （FC） synthesis image,it is yellow in color in Sargassum water. The bound line of Sargassum water in FC is more clearly than that in TC. TM4 presents largest difference between Sargassm and no Sargassum water,TM3 also shows small difference between Sargassm and no Sargassum water. All four methods can extract Sargassum from nature water. Among the four meth-ods,normalized differential vegetation index presents highest precision compared to the results obtained from IKONOS data.