基于EOS-Terra/MODIS的沙尘暴遥感监测方法对比研究

通过分析沙尘暴的波谱响应特征及EOS-Terra/MODIS传感器通道的特点,阐述了利用EOS-Terra/MODIS进行沙尘暴监测的机理,提出了利用MODIS进行沙尘暴监测的热红外双通道差值法、三通道彩色合成直方图均衡增强法及基于双通道域值的叠加分析法,并进行了示范比较研究。研究指出基于MODIS采用双通道法进行沙尘暴遥感监测有其局限性,不能快速、有效地提取沙尘暴信息。三通道彩色合成直方图均衡增强法直观判读效果较好,但缺少定量化分析。基于双通道域值的叠加分析法是一种集定量、定性分析于一体的监测方法,有利于对沙尘暴信息的准确提取,为利用MODIS数据进行沙尘暴监测提供了有效手段。

Comparative study on methods of monitoring sandstorms based on EOS-Terra/MODIS

This paper discusses the mechanism of monitoring sandstorms based on EOS-Terra/MODIS by analyzing the spectral response characteristics of sandstorms and the bands from MODIS sensor.Three methods including the difference method of two thermo-bands,histogram equilibrium method of pseudo-color composition of the three bands,and superposition analysis based on the boundary limit values of two bands are put forward.It is pointed out that the first two methods have their limits because they can not be used to fleetly and effectively derive the information about sandstorms.The superposition method based on the thresholds of two bonds is an ideal method to accurately derive the information about sandstorms and qualitatively and quantitatively analyze sandstorms.Examples are also given to process the data on the day with a sandstorm on April 10,2003 and the day without sandstorm on January 16,2004.