基于数字滤波的主动式高光谱成像系统及其波长标定

Active hyperspectral imaging system based on digital filtering and its calibration

基于数字滤波技术,提出了获取物体反射光谱数据立方体和光谱响应曲线的主动式新型高光谱成像系统。对传统WDF型瓦兹渥斯反射式单色仪进行了改装,在入射光一定的情况下,增大出射光通量,提高了照射在物体表面的光强。利用数字滤波方式代替光学窄带滤波器,解决了多个光学滤光片不能连续可调和其他滤波器成本高的问题,建立了波长连续可调,带宽可调的高光谱成像系统。针对系统的特点和采集方式,提出了适当的定标方式,其波长误差<2nm。得到了绿色树叶效果良好的光谱数据立方体和响应曲线,表明提出的系统适用于实验室中小视场内的光谱成像测量研究。

A novel active hyperspectral imaging system in which a digital filter is specially designed as a creative component is developed for calculating the spectral cube and spectral response of an object. Based on the refit of a general WDF Wadsworth monochromator, the system enhances the exit flux and improves the optical intensity radiated on the object when the light incident keeps a constant. Furthermore, the optical narrowband filter is replaced by a digital filter. The hyperspectral imaging system resolves the problem of the system with a number of optical filters which can not be adjusted continuously, and it has lower cost than other filters. Meanwhile, the system is easy to implement, wavelength tunable, and band variable. According to the characters of the system and image gathering, the calculation method is supplied and the inaccuracy is less than 2 nm. The spectral cube and response of green leaves are successfully achieved, and the system is suitable for the spectral measurements with a small view in laboratory.