Development of a Wide Range Hyperspectral Imager for Evidence Examination
ZHAO Xue-jun1, HUANG Xiao-chun2, WANG Chang-liang2*, CAI Neng-bin2*, YIN Lu3, LU Yu-xian3, PAN Ming-zhong3, 4
1. Shanghai Research Institute of Criminal Science and Technology, Shanghai Key Laboratory of Crime Scene Evidence, Shanghai 200083, China
2. Shanghai Institute of Forensic Science, Public Security Bureau, Shanghai Key Laboratory of Crime Scene Evidence, Shanghai 200083, China
3. Hangzhou Academy of Spatial Information Technology, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Hangzhou 311225, China
4. Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China
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.
Key words：Hyperspectral imaging; Spectral characteristics; Band range; Wide range hyperspectral; Evidence detection
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(03): 674-678.
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. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2020, 40(03): 674-678.
