光谱学与光谱分析, 2020, 40 (3): 674, 网络出版: 2020-03-25
宽波段高光谱成像技术在物证检验中的应用
Development of a Wide Range Hyperspectral Imager for Evidence Examination
高光谱成像 光谱特征 波段范围 宽波段高光谱 物证探测 Hyperspectral imaging Spectral characteristics Band range Wide range hyperspectral Evidence detection
摘要
高光谱成像技术在物证检验领域的应用具有非常重要的意义, 其不仅能够记录物证的光谱特征用以分析物质成分, 而且能够准确记录不同成分的空间分布情况, 从而实现无损、 快速、 定位分析物证成分的功能。 高光谱成像物证检验技术的光谱检测范围通常集中在可见-近红外区域, 而现有基于高光谱成像技术的物证检测设备基本只能单独覆盖可见波段或者近红外波段, 无法实现可见-近红外的宽波段检测需求。 为了拓宽成像光谱仪的检测波段范围从而实现提高物证检验精度和增加物证检验种类的目的, 首先分析了推扫式成像光谱仪的组成结构及工作原理, 剖析了直接研制宽波段成像光谱仪的技术难度和高昂成本, 最后提出了将短波段范围的400~1 000 nm可见高光谱成像仪和900~1 700 nm近红外高光谱成像仪相结合的方式实现宽波段范围的方法。 通过2台高光谱成像设备线视场匹配将独立的2台设备联合作为1台设备使用, 采用定标板辅助装调的方法实现2台高光谱成像仪线视场的像素级拼接, 将设备拼接带来的误差降低到不影响输出结果的程度, 最终研制出一种波段范围可达400~1 700 nm的可见-近红外宽波段高光谱物证检测设备。 搭建实验系统, 分别固定2台独立的短波段范围高光谱成像光谱仪, 利用平移台带动检材沿着垂直于线视场的方向移动实现推扫, 所获取的数据立方体具有400~1 700 nm的宽光谱范围, 400~1 000 nm的光谱分辨率为2.5 nm, 1 000~1 700 nm的光谱分辨率为4 nm。 实验结果表明该方法的可行性, 对于宽波段高光谱成像仪的研制具有指导意义, 使高光谱成像仪在物证检验领域具有更高的应用价值和更广的应用范围。
Abstract
The hyperspectral imaging technology is significant in the field of evidence examination. Because of the spectral characteristics and spatial distribution characteristics, non-destructive, rapid and positioning analysis of material evidence can be realized. The spectral detection range of hyperspectral imaging in evidence examination usually concentrates on visible-near infrared region. However, the existing material evidence testing equipment based on hyperspectral imaging technology can only cover visible or near infrared band alone, which cannot meet the wide-band detection requirements. In order to widen the detection band so that the accuracy of evidence examination can be improved, this paper firstly analyses the composition, structure and working principle of push-broom imaging spectrometer, secondly analyses the technical difficulty and high cost of developing wide-band imaging spectrometer, and finally puts forward the idea of combining the visible imaging spectrometer and the near infrared imaging spectrometer to achieve a wide band range. Two independent equipments are combined as one equipment by matching the line-of-sight of two imaging spectrometer. The calibration board is used to realize the pixel-level splicing of line-of-sight so that the error caused by equipment splicing is reduced to the extent that it does not affect the output results. Finally, an evidence detection device of visible-near infrared wide-band hyperspectral imaging spectrometer with a band range of 400~1 700 nm is developed. Two independent short-band hyperspectral imaging spectrometers are fixed, and a moving platform is used to drive the sample along the direction perpendicular to the line-of-sight. The obtained data cube has a broad spectral range of 400~1 700 nm, the spectral resolution of 400~1 000 nm is 2.5 nm, and the spectral resolution of 1 000~1 700 nm is 4 nm. The experimental results show that the method is feasible which has guiding significance for the development of broad band hyperspectral imaging spectrometer. It makes the imaging spectrometer have higher application value and wider application scope in the field of evidence examination.
赵雪珺, 黄晓春, 王长亮, 蔡能斌, 尹禄, 卢禹先, 潘明忠. 宽波段高光谱成像技术在物证检验中的应用[J]. 光谱学与光谱分析, 2020, 40(3): 674. ZHAO Xue-jun, HUANG Xiao-chun, WANG Chang-liang, CAI Neng-bin, YIN Lu, LU Yu-xian, PAN Ming-zhong. Development of a Wide Range Hyperspectral Imager for Evidence Examination[J]. Spectroscopy and Spectral Analysis, 2020, 40(3): 674.