基于环境减灾小卫星(HJ-1B)的地表温度单窗反演研究

Research on Using a Mono-Window Algorithm for Land Surface Temperature Retrieval from Chinese Satellite for Environment and Natural Disaster Monitoring(HJ-1B) Data

地表温度是地球环境中的一个关键参数,可探测地表温度的热红外波段在光谱谱段中占有重要位置。针对近年来发射的HJ-1B星波段特点,本研究在基于影像的COST模型大气校正基础上,以宁夏为研究区,采用无需大气水汽含量参数的单窗算法反演地表温度,并采用同步的MODIS温度产品对比验证,结果表明该法具有<1 K的较高精度。同时,对该法的关键参数地表比辐射率进行了敏感性分析,发现该法对比辐射率不大敏感,其在中等程度的变化时,其误差<0.5 K。从而说明该法反演地表温度的可靠性,也表明了环境减灾星具有较高精度的地表温度探测能力。

Land surface temperature（LST） is a key parameter in earth environment,the thermal infrared band that can detect LST plays an important role in spectroscopy.Aiming to the latest optical and thermal bands of HJ-1B satellite,the LST retrieval over Ningxia plain was implemented using a mono-window algorithm without atmospheric water vapor content input,based on the COST model for atmospheric correction.Considering the difficulty of obtaining simultaneous ground measured data,the MODIS LST product was adopted as a standard to test the approach. The comparison and validation indicate that this method has good reliability with accuracy of less than 1 K.In addition,the sensitivity analysis is performed for land surface emissivity,and the result shows that this variable was not sensitive to LST,because the LST error is less than 0.5 K when it varies at medium level.This study proves that the satellite data has higher availability for detecting LST.