NOAA卫星沙尘暴光谱特征分析及信息提取研究

通过对2000—2002年多次沙尘暴过程NOAA卫星AVHRR资料的分析,研究了沙尘、云、沙漠、戈壁、积雪、裸地、植被等不同目标物的光谱特性,发现沙尘暴在AVHRR-2中各通道均有不同程度的反映。1,2通道中沙尘的反射率较高(介于云和沙漠之间);4,5通道的亮温低于晴空地表高于云;在3通道中沙尘表现的很独特,其亮度温度为所有研究目标物中最高的,表明通道3包含较多的沙尘信息,AVHRR-3取代AVHRR-2后对监测沙尘有不利影响。在此基础上提出定量提取沙尘信息的两种沙尘判识指数,并利用沙尘判识指数成功地提取多次沙尘暴过程的沙尘信息。结果表明：利用多通道组合沙尘判识指数能够对沙尘信息进行有效提取。

Spectrum Characteristic Analysis of Dust Storm and Dust Identified Using NOAA Satellites Data

Spectrum characteristics of several regions such as dust storm, cloud, desert, Gebi desert, snow, soil and vegetation were analyzed using NOAA/AVHRR data during the years from 2000 to 2002. The characteristics of dust storm in NOAA/AVHRR-2 are that: The reflectances of channel 1 and 2 are higher than the desert and lower than the clouds; the brightness temperature of channel 4 and 5 are lower than the regions in where are clear, and higher than clouds. The brightness temperature of dust storm in channel 3 is unusual, the temperature is the highest in all of the regions. It is show that there is more trace of dust in channel 3. It is disadvantage to monitor dust storm when AVHRR-2 have been replaced by AVHRR-3. Two dust identified indexes, which identify dust quantificational from AVHRR, were put forward. The dust had been identified successfully in many dust storm cases using the dust identified indexes. The results show that dust storm could be identified effectively by the dust identified indexes which are composed of multi-channel value.