基于LCTF的多光谱成像系统辐射定标

Radiometric Calibration of Multi-Spectral Imaging System Based on Liquid Crystal Tunable Filter

基于LCTF的多光谱成像系统与传统机械滤光片式的成像光谱仪有所不同,它利用液晶电控双折射效应实现分光,从而得到二维图像信息和一维光谱信息。针对基于LCTF的多光谱成像系统自身的结构和性能特点,采用了基于积分球+光谱辐射计的定标方法,从暗电流、稳定性、响应均匀性和响应线性度等方面阐述了定标内容,通过两点校正的图像校正算法提高了图像质量,并对辐射定标的不确定度进行了分析,通过实验验证了定标精度。结果表明:采用的定标方法和数据处理算法获取的定标系数准确有效,定标后的系统精度较好。

The multi-spectral imaging system based on LCTF is different from the traditional mechanical filter imaging spectrometer,which is divided into two-dimensional image information and one-dimensional spectral information by using liquid crystal electric double refraction effect.In view of the particularity of the structure and properties of multi-spectral imaging system based on LCTF,the integrating sphere and spectral radiometer radiometric calibration method is put forward.It describes the calibration content from the dark current,stability,uniform response and response linearity.The image quality is improved by two point correction algorithm,and radiation calibration uncertainty is analyzed.Then the calibration accuracy is verified by experiments.The results show that the calibration coefficients obtaining by the calibration method and data processing algorithm in this paper is accurate and effective,and the accuracy of the system is better.