Hobbs Steven, Lambert Andrew, Ryan Michael J, Paull David J, Haythorpe John
School of Engineering and Information Technology (SEIT), University of New South Wales Canberra, Northcott Drive, Canberra, ACT 2600, Australia.
Capability Associates Pty Ltd., Canberra, ACT 2600, Australia.
Sensors (Basel). 2021 Jun 27;21(13):4398. doi: 10.3390/s21134398.
Near infrared (NIR) remote sensing has applications in vegetation analysis as well as geological investigations. For extra-terrestrial applications, this is particularly relevant to Moon, Mars and asteroid exploration, where minerals exhibiting spectral phenomenology between 600 and 800 nm have been identified. Recent progress in the availability of processors and sensors has created the possibility of development of low-cost instruments able to return useful scientific results. In this work, two Raspberry Pi camera types and a panchromatic astronomy camera were trialed within a pushbroom sensor to determine their utility in measuring and processing the spectrum in reflectance. Algorithmic classification of all 15 test materials exhibiting spectral phenomenology between 600 and 800 nm was easily performed. Calibration against a spectrometer considers the effects of the sensor, inherent image processing pipeline and compression. It was found that even the color Raspberry Pi cameras that are popular with STEM applications were able to record and distinguish between most minerals and, contrary to expectations, exploited the infra-red secondary transmissions in the Bayer filter to gain a wider spectral range. Such a camera without a Bayer filter can markedly improve spectral sensitivity but may not be necessary.
近红外（NIR）遥感在植被分析以及地质调查中都有应用。对于外星应用而言，这在月球、火星和小行星探测中尤为重要，在这些探测中已识别出在600至800纳米之间呈现光谱现象学的矿物。处理器和传感器可用性方面的最新进展使得开发能够返回有用科学结果的低成本仪器成为可能。在这项工作中，在推扫式传感器内对两种Raspberry Pi相机类型和一台全色天文相机进行了试验，以确定它们在测量和处理反射光谱方面的效用。对所有15种在600至800纳米之间呈现光谱现象学的测试材料进行算法分类很容易实现。针对光谱仪的校准考虑了传感器、固有图像处理管道和压缩的影响。结果发现，即使是在STEM应用中很受欢迎的彩色Raspberry Pi相机也能够记录并区分大多数矿物，而且与预期相反的是，它利用了拜耳滤镜中的红外二次传输来获得更宽的光谱范围。这种没有拜耳滤镜的相机可以显著提高光谱灵敏度，但可能并非必要。
