非同温对平面混合像元温度发射率分离的影响分析

Analysis of the Non-isothermal Effects on the Temperature/Emissvity Separation of Flat Mixed Pixel

在热红外光谱区域,假设非同温平面混合像元的发射率为r-emissivity,那么它的辐射温度是随波长变化的。以典型的由土壤和植被组成的非同温平面混合像元为例,分析了非同温对其辐射温度的影响,并给出体现辐射温度变化的可能的方法。利用模拟的热红外高光谱数据对该方法进行了验证,验证结果表明,该方法能够较好地刻画非同温平面混合像元辐射温度随波长的变化,提高了非同温平面混合像元r-emissivity的反演精度。

In the thermal infrared spectral region, the radiometric temperature of flat non-isothermal mixed pixel varies with the wavelength if we assumed that its emissivity can be represented by r-emissivity. The typical flat non-isothermal mixed pixel composed of soil and vegetation is taken as an example, analyzing the non-isothermal effects on the radiometric temperature of the pixel, and giving a possible method to present the variation of radiometric temperature change. In order to validate the method, simulated hyper spectral thermal infrared dataset is generated. The validation results show that the method can characterize the change of flat non-isothermal mixed pixel with wavelength well and improve the inversion precision of r-emissivity of flat non-isothermal mixed pixel.