中红外双通道夜间数据地表温度反演方法

Retrieval of night-time land surface temperature from two mid-infrared channels data

地表温度反演是红外定量遥感的核心内容之一.与热红外（8～14μm）数据相比，中红外（3～5μm）波谱区大气透过率更高、对发射率的敏感性更低，在温度反演方面具有独特的优势.引入热红外地表温度反演思路，发展了仅利用夜间中红外双通道数据的地表温度反演算法，分析了宽通道组合（3～4 μm和4～5 μm）和窄通道组合（3929～3.989 μm和4.020～4.080μm）模式下的温度反演精度以及模型对噪声和发射率的敏感性.结果表明，宽、窄两种通道组合模型的温度反演精度分别为～0.5 K和～0.3 K；噪声等效温差和地表发射率误差对窄通道组合模型的影响更大.

Retrieval of land surface temperature （LST） is one of the key issues in mid- and thermal-infrared quantitative remote sensing. Compared with thermal-infrared （8～14μm） channel, mid-infrared （3～5μm） channel with the advantages, such as more transparent of atmospheric window and less sensitive to the surface emissivity, might be used to retrieve the LST. A two-channel LST retrieval algorithm, which only uses the night-time data of two mid-infrared channels and introduces the experience of thermal infrared LST retrieval method, has been proposed in this paper. The retrieval accuracies of two channel-combination models, i.e., narrow-channel model （3.929～3.989 μm and 4.020～4.080 μm） and wide-channel model （3～4μm and 4～5μm）, were analyzed in detail. The results show that the LST retrieval accuracies of wide-channel and narrow-channel models are approximate ～ 0.5K and ～ 0.3K, respectively. However, compared with the wide-channel model, the noise equivalent temperature difference （NEΔT） and the error of land surface emissivity （LSE） can produce a greater influence on the narrow-channel model.