基于MODIS数据的陕西省地表温度的空间分布研究  

Spatial Distribution of Land Surface Temperature Retrieved from MODIS data in Shaanxi Province

作　　者：秦晓敏[1] 覃志豪[1] 毛克彪[1] 

机构地区：[1]南京大学国际地球系统科学研究所,江苏南京210093

出　　处：《干旱区地理》2005年第4期548-553,共6页Arid Land Geography

基　　金：自然科学基金"用MODIS数据反演地表温度的算法及其参数"项目(40471096)国家重点基础研究发展规划(973)项目

摘　　要：由热红外波段秋得的影像是地物发射的热辐射量的直接记录,可用于地面温度和热量空间分布的动态监测。本文利用MODIS数据可见光波段b1、近红外波段b2和中红外波段b19,获得所需要的两个基本参数:地表比辐射率与大气透过率;然后对于热红外波段b31、b32,运用劈窗算法反演出陕西省地表温度:并与陆面实际状况进行了对照分析。结果表明,这一方法能获得较合理的地表温度,符合陕西省实际地表状况;另外也为应用MODIS热红外波段数据进行大范围实时监测地表温度提供了新的途径。A thermal-infrared remote sensing image can directly record the radiation of surface features, and therefore can be used for measuring land surface temperature （LST） and monitoring the caloric spatial distribution. At present, there are several kinds of methods for retrieving LST. Of all the methods on land surface temperature retrieval, split-window algorithm is the uppermost one to retrieve the LST by using thermal-infrared data. In this paper, the values of land surface temperature in Shaanxi Province are calculated by means of a split-window method based on MODIS data. The algorithm needs two import parameters. As MODIS image has the lower resolution of one kilometer, and vegetation, soil and water can be regarded as the three main ingredients for one pixel of MODIS image. In succession, the ratio of three ingredients can be obtained by NDVI According to the ratio, the emissivity of land surface can be estimated. On the other hand, the atmospheric transmittance can be estimated on the basis of the relationship between atmospheric transmittance and water content. When the values of LST in Shaanxi Province are worked out, the frondose process is as follows： First of all, the surface emissivity is computed from the band 1 and band 2, and the atmospheric transmittance is computed from the band 2 and band 19. Then in conjunction with the brightness temperature of band 31 and band 32, the values of land surface temperature are derived. In this method, the most important strongpoint is that the used parameters can be estimated from the same image, which is suitable for the MODIS image with many bands. Finally an analysis is carried out according to the practical ground conditions, and the graph of LST indicates the spatial difference, urban heat-island effect and different surface features with the different temperatures. The results reveal that the method can be used to acquire the reasonable values of land surface temperature. Thus this paper shows a good manner for monitoring large-scale and real-time land

关 键 词：地表温度 MODIS 劈窗算法 大气透过率 地表比辐射率 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置]