粗糙度与观测角度对岩石热红外光谱解混影响规律的实验研究

The spectral unmixing is a key technology in the quantitative remote sensing inversion of rock, which plays an important role in the mine detection and geology mapping. However, most of rock spectral unmixing researches using thermal infrared spectrum focus on the particle sample, and the thermal infrared spectral library was established based on the particle mineral as well, which would influence the accuracy of spectral unmixing of natural massive rock. In this study with combination of experiment and theory analysis, the surface morphology of natural massive rock is completely considered, and the roughness and observation angle are selected as the factors to affect spectral emissivity and unmixing efficiency of massive rock. The roughness and spectrum of rock are respectively acquired from a high precision 3D measuring instrument and the thermal infrared spectrometer, then the effect characteristic of roughness and observation angle on thermal infrared spectrum and spectral unmixing is studied. Furthermore, the influencing effect and its mechanism are analyzed in terms of the radiation transfer theory. This study is expected to promote the development of quantitative remote sensing of rock and mineral with improving the spectral unmixing accuracy. This study not only has importance in scientific significance, but also has importance in practical significance.

目前光谱解混已经成为岩矿定量遥感中的一种重要技术，在地质找矿和地质填图方面发挥了重要作用。然而，现有的岩石热红外光谱解混研究与应用，大多针对颗粒岩石，所利用的光谱库也多为颗粒光谱库，无法满足自然界块状岩石的高精度光谱解混要求。本项目以实验手段为主并结合理论分析，充分考虑自然界块状岩石表面实际形态，将粗糙度和观测角度作为影响光谱发射率与解混精度的影响因素，以现代高精度的三维形态测量仪器和热红外光谱辐射计作为岩石粗糙度和热红外光谱的测试手段，来研究自然界块状岩石的表面粗糙度和观测角度对岩石光谱特征及线性解混的影响规律。然后，依据红外辐射传输理论对其机理进行分析，揭示岩石的粗糙度和观测角度对光谱发射率和解混效果的影响机理。研究结果可望推动我国在岩矿定量遥感领域的研究进展，提高岩石光谱解混的精度。其研究不仅具有重要的科学意义，同时具有重要的实际意义。

目前光谱解混已经成为岩矿定量遥感中的一种重要技术，在地质找矿和地质填图方面发挥了重要作用。然而，现有的岩石热红外光谱解混研究与应用，大多针对颗粒岩石，所利用的光谱端元库也多为颗粒端元，无法满足自然界块状岩石的高精度光谱解混要求。本项目以实验手段为主并结合理论分析，充分考虑自然界块状岩石表面实际形态，将粗糙度和观测角度作为影响光谱发射率与解混精度的影响因素，以现代高精度的三维形态测量仪器和热红外光谱辐射计作为岩石粗糙度和热红外光谱的测试手段，来研究自然界块状岩石的表面粗糙度和观测角度对岩石光谱特征及线性解混的影响规律。然后，依据红外辐射传输理论对其机理进行分析，揭示岩石的粗糙度和观测角度对光谱发射率和解混效果的影响机理。.研究结果表明，粗糙度和观测角度对岩石光谱解混有重大影响。当岩石和矿物端元具有相同的粗糙度时，光谱解混误差小；当岩石和矿物端元具有不同粗糙度时，解混误差大为增加。同时，当岩石和矿物端元的观测角度相差在0°～20°范围内，解混误差小于５％，当观测角度相差大于20°时，观测角度对光谱解混有显著影响。机理分析结果表明，岩石的热红外光谱特征的影响因素主要有表散射、体散射和空腔效应等，它们的共同作用结果是导致岩石热红外光谱随粗糙度、观测角度而发生变化的主要原因。