Abstract Methods to retrieve urban surface temperature (Ts) from remote sensing observations with sub-building scale resolution are developed using the Discrete Anisotropic Radiative Transfer (DART, Gastellu-Etchegorry et al., 2012) model. Corrections account for the emission and absorption of radiation by air between the surface and instrument (atmospheric correction), and for the reflected longwave infrared (LWIR) radiation from non-black-body surfaces (“emissivity” correction) within a single modelling framework. The atmospheric correction a) can use horizontally and vertically variable distributions of atmosphere properties at high resolution ( The atmospheric correction method evaluation, with simultaneous “near” (~15 m) and “far” (~155 m) observations, has a mean absolute error of 0.39 K. Using broadband approximations, the emissivity correction has clear diurnal variability, particularly when a cool and shaded surface (e.g. north facing) is irradiated by warmer (up to 17.0 K) surfaces (e.g. south facing). Varying the material emissivity with bulk values common for dark building materials (e = 0.89 → 0.97) alters the corrected roof (south facing) surface temperatures by ~3 (1.5) K, and the corrected cooler north facing surfaces by less than 0.1 K. Corrected observations, assuming a homogeneous radiation distribution from surfaces (analogous to a sky view factor correction), differ from a heterogeneous distribution by up to 0.25 K. Our proposed correction provides more accurate Ts observations with improved uncertainty estimates. Potential applications include ground-truthing airborne or space-borne surface temperatures and evaluation of urban energy balance models.

中文翻译：

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使用 3D 辐射传输模型对地基热成像进行大气和发射率校正

摘要 使用离散各向异性辐射传递（DART，Gastellu-Etchegorry 等人，2012 年）模型开发了从具有子建筑尺度分辨率的遥感观测中反演城市表面温度 (Ts) 的方法。校正考虑了表面和仪器之间空气对辐射的发射和吸收（大气校正），以及在单个建模框架内从非黑体表面反射的长波红外 (LWIR) 辐射（“发射率”校正）。大气校正 a) 可以在高分辨率下使用大气属性的水平和垂直变化分布（大气校正方法评估，同时“近”（~15 m）和“远”（~155 m）观测，具有平均绝对值0.39 K 的误差。 使用宽带近似值，发射率校正具有明显的昼夜变化，特别是当凉爽和阴凉的表面（例如朝北）被温暖（高达 17.0 K）的表面（例如朝南）照射时。改变材料发射率与深色建筑材料常见的体积值 (e = 0.89 → 0.97) 会使修正后的屋顶（朝南）表面温度改变 ~3 (1.5) K，修正后较冷的朝北表面改变小于 0.1 K。假设来自表面的均匀辐射分布（类似于天空视角因子校正）的校正观测与不均匀分布的差异高达 0.25 K。我们提出的校正提供了更准确的 Ts 观测和改进的不确定性估计。