以碱性长石花岗岩为例,采用Turbo FT便携式红外光谱辐射计对其4种组成矿物(钾长石、斜长石、白云母、石英)分别进行0.71—1mm颗粒室外常温、0.71—1mm颗粒室内80℃、块体室外常温的热红外(7—14μm)光谱特征测试,以测试结果作为端元光谱对室外常温下测得的块状碱性长石花岗岩光谱进行解混,并与将ASU光谱作为端元光谱的解混效果进行比较。结果表明,当岩石与矿物端元的光谱测试条件相同时,解混效果最好;使用块状端元光谱能有效解混块状岩石光谱;ASU颗粒光谱不能解混块体岩石的矿物成分及含量。试验结果对遥感地质及矿物填图的研究具有指导意义。

Distinguishing and converting mineral ingredient and content based on the spectrum unmixing of rock are an important direction of high-spectral remote sensing. The thermal infrared spectrum of a block of alkali feldspar granite is measured by using Turbo FT portable infrared spectral radiometer in outdoor site and normal temperature, and the thermal infrared spectrums (7—14μm) of four mineral ingredients of the rock, that is, potash feldspar, plagioclase, white mica, and quartz are also measured under three different conditions, i.e. grain sample of 0.71—1mm in outdoor site and normal temperature, grain sample of 0.71—1mm in indoor site and 80℃, and block sample at outdoor site and normal temperature. Then the spectrum of the rock is linearly decomposed by using the spectrums of the four minerals as the end members, and the results are compared with the results that the ASU spectrum is used as the end member. The result shows that the unmixing effect is best when the spectrums of rock and the end member mineral are measured in the same condition; and that the spectrum of block rock could be decomposed by the spectrums of block minerals, however it could not be decomposed by ASU spectrum. The experimental result is beneficial to the remote sensing geology and mineral mapping.