地表发射率不同的估算方法对地表温度的影响

随着遥感技术的日益成熟,用热红外波段反演地表温度的方法也日趋完善,其中一个关键参数--地表发射率的估算,直接影响着地表温度的反演结果。基于TM6的热红外波段,分别采用最常用的Van的地表发射率估算方法和综合了覃志豪与Sobrino的估算方法,对北京地区的地表温度进行了反演,并在此基础上对这2种估算方法所得结果进行了比较,从而为找出更为有效的地表发射率估算公式提供依据。结果表明,对于农林地2种估算方法都比较适合,但是对于水体和城市等人口密集地区,则需要和当地的实测数据进行比对,从而确定更为合适有效的估算方法,以得到更为精确的地表温度结果。

Impacts on the Land Surface Temperature for Different Methods of Land Surface Emissivity Estimation

In these methods,land surface emissivity is the key parameter,so land surface emissivity estimation has a direct impact on the land surface temperature results.Now,NDVI is used for land surface emissivity retrieval frequently.In this paper,in order to get the land surface temperature of Beijing,the writer used Van’s land surface emissivity estimation method and a combination of Qin Zhihao’s and Sobrino’s estimation methods,then compared the two results.The results showed that these two estimation methods were both suitable for farmland and forest land,but for water and urban,with the purpose of getting a more accurate land surface temperature results,comparing the local measured data and retrieval results,and then confirming the more appropriate estimation method.