小行星表面温度是研究行星热物理特性的关键参数。 太阳系中小天体的轨道动力学研究具有多种实际应用, 包括预测行星体轨道和撞击产生的陨石坑率、 选择航天器合适的探测采样目标。 对于近地天体, 分析它们的轨道结构、 星体的轨道演化和未来的偏移轨迹等近地天体动力学特性具有重要意义。 中国即将发射“天问二号”, 对近地小行星2016HO3进行热辐射探测和风化层采样。 “天问二号”预计在不远的将来到达环绕2016HO3的轨道。 研究了一种温度-比辐射率分离算法, 用于从“欧西里斯-雷克斯”热辐射光谱仪(OTES)辐亮度数据中, 计算与小行星2016HO3热物理性质相近的行星“贝努”(Bennu)的表面温度。 温度-比辐射率分离算法融合了发射率归一化法(NEM)、 比值法(RAT)、 发射率最大最小值差法(MMD), 是目前精度较高的一种表面温度反演算法。 为了验证算法的准确性, 使用了CRISM光谱库的光谱数据, 通过改变目标的温度和算法使用波段, 来研究算法对二者的敏感性。 其中, 因为仪器波段限制等原因, 尚无使用波段对算法的误差推导。 研究结果表明: (1)设置温度范围为115~415 K, 步长5 K, 随着温度的增加, 反演温度的均方根误差增加, 而发射率的误差大致不变。 (2)样本温度为295 K, 算法使用的波段起点为7.5 μm, 采样间隔0.04 μm, 终点为10~13.8 μm, 步长0.2 μm。 发现波长范围在7.5~13.8 μm, 算法的MMD模块的精度最高。 使用算法求解行星“贝努”的表面温度, 结果表明: 在剔除了大太阳高度角和高纬像素的情况下, 算法计算的温度的误差平均值为-0.366 0 K, 误差的标准差为1.0393 K。

The surface temperature of asteroids is a key parameter in studying the thermophysical properties of planets. The study of orbital dynamics of small and medium-sized celestial bodies in the solar system has a variety of practical applications, including predicting the orbit of planetary bodies and the cratering rate caused by impact and selecting appropriate detection and sampling targets for spacecraft. For NEAs, it is significant to analyze their orbital structure, orbital evolution, and future offset trajectory of Neos［1］. China is about to launch “tian wen-2” to detect the thermal radiation and sample the weathering layer of the near-Earth Asteroid 2016HO3. “Tianwen-2” is expected to reach orbit around 2016HO3 shortly. this paper studies a temperature-specific emissivity separation algorithm, which is used to extract the radiance data from the “Osiris Rex” thermal radiation spectrometer (OTES), Calculate the surface temperature of the planet "Bennu" with similar thermophysical properties to the asteroid 2016HO3［2］. The temperature emissivity separation algorithm combines the emissivity normalization method (NEM), ratio method (rat), and emissivity maximum-minimum difference method (MMD). It is a surface temperature inversion algorithm with high accuracy at present. To verify the algorithm’s accuracy, this paper uses the spectral data of the CRISM spectral library to study algorithm’s sensitivity to the target temperature and the band. Among them, due to the limitation of the instrument and other reasons, there is no error derivation of the length of the wave band. The results show that: (1) set the temperature range to 115~ 415 K and the step size to 5 K. With the increase in temperature, the root means square inversion error temperature increases and the error of emissivity is roughly unchanged. (2) The sample temperature is 295 K, and the starting point of the band used by the algorithm is 7.5 μ m. Sampling interval 0.04 μm. The endpoint is 10~13.8 μm. Step 0.2 μm. It is found that the wavelength range is 7.5~13.8 μm. The MMD module of the algorithm has the highest accuracy. The algorithm is used to solve the surface temperature of the planet “Bennu”. The results show that the average error of the temperature calculated by the algorithm is -0.366 0 K, and the standard deviation is 1.039 3 K except for pixels with large solar altitude angles and in high latitudes.