College of Surveying and Geo-Informatics, Tongji University, Shanghai 200092, China.
Key Laboratory of Space Active Opto-Electronics Technology of the Chinese Academy of Sciences, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China.
Sensors (Basel). 2023 Jul 3;23(13):6128. doi: 10.3390/s23136128.
This paper evaluates the potential application of Raman baselines in characterizing organic deposition. Taking the layered sediments (Stromatolite) formed by the growth of early life on the Earth as the research object, Raman spectroscopy is an essential means to detect deep-space extraterrestrial life. Fluorescence is the main factor that interferes with Raman spectroscopy detection, which will cause the enhancement of the Raman baseline and annihilate Raman information. The paper aims to evaluate fluorescence contained in the Raman baseline and characterize organic sedimentary structure using the Raman baseline. This study achieves spectral image fusion combined with mapping technology to obtain high spatial and spectral resolution fusion images. To clarify that the fluorescence of organic matter deposition is the main factor causing Raman baseline enhancement, 5041 Raman spectra were obtained in the scanning area of 710 μm × 710 μm, and the correlation mechanism between the gray level of the light-dark layer of the detection point and the Raman baseline was compared. The spatial distribution of carbonate minerals and organic precipitations was detected by combining mapping technology. In addition, based on the BI-IHS algorithm, the spectral image fusion of Raman fluorescence mapping and reflection micrograph, polarization micrograph, and orthogonal polarization micrograph are realized, respectively. A fusion image with high spectral resolution and high spatial resolution is obtained. The results show that the Raman baseline can be used as helpful information to characterize stromatolite organic sedimentary structure.
本文评估了拉曼基线在表征有机沉积物中的潜在应用。以地球上早期生命生长形成的层状沉积物（叠层石）为研究对象，拉曼光谱是探测深空外星生命的重要手段。荧光是干扰拉曼光谱检测的主要因素，它会导致拉曼基线增强并湮灭拉曼信息。本文旨在评估拉曼基线中包含的荧光，并利用拉曼基线来表征有机沉积结构。本研究通过结合光谱图像融合和映射技术，获得了高空间和高光谱分辨率的融合图像。为了阐明有机物质沉积的荧光是导致拉曼基线增强的主要因素，在 710μm×710μm 的扫描区域内获得了 5041 条拉曼光谱，并比较了检测点明暗层灰度与拉曼基线之间的相关机制。通过结合映射技术检测碳酸盐矿物和有机沉淀物的空间分布。此外，基于 BI-IHS 算法，分别实现了拉曼荧光映射与反射显微图、偏光显微图和正交偏光显微图的光谱图像融合，得到了具有高光谱分辨率和高空间分辨率的融合图像。结果表明，拉曼基线可作为有用信息来表征叠层石有机沉积结构。
