AOTF高光谱成像系统的标定及性能测试

Calibration and Characterization of an AOTF-based Hyperspectral Imaging System

提出了一套声光可调谐滤光器高光谱成像系统的标定及性能测试方法,并针对研制的高光谱成像系统原理样机进行了实验验证.结果表明:所提方法可以较为完整、准确地验证系统的光谱域及空间域特性;经过光谱图像平场校正可明显改善系统响应的非均匀性;通过自动控制相机曝光时间及像元增益的方式逐波段进行光谱灵敏度校正,可以提高系统的信噪比;采用改变相机曝光时间并测定系统响应的方式验证系统的光谱线性度,较传统方法更为方便,且可有效节约测试成本.该方法同样适用于基于液晶可调谐滤光器等的高光谱成像系统.

A systemic calibration and a characterization approach were presented for acousto optic tunable filter based hyperspectral imaging system. A series of tests were conducted to validate the performance of a self-integrated hyperspectral imaging system. Results show that the presented approach effectively validate the systematic characteristics in both spectral and spatial domains. Through flat-fielding correction, the system responsivity non-uniformity, known as pattern noise, is apparently eliminated. The spectral sensitivity of the system is corrected by controlling both the camera exposure time and digital gains at each wavelength, which significantly improve the signal to noise ratio of the system. By studying the system outputs with different camera exposure time, instead of using an attenuator to adjust the input light intensity, a more efficient and cost effective approach to measure the spectral linearity of the system is presented. The proposed methods are also applicable to the liquid crystal tunable filter based hyperspectral imaging systems.