基于面阵凝视扫描成像的声光光谱成像系统及其图像拼接验证试验

可见---近红外波段(400~1000 nm)成像光谱仪是光谱探测的重要组成部分。基于地基可见-近红外成像光谱仪的实际应用要求，提出了一种采用面阵探测器的凝视扫描成像光谱仪。该光谱仪还采用了一种新型分光器件声光可调谐滤波器(Acousto-optic tunable filter, AOTF)。其特点在于光谱的选择和施加在它上的射频信号频率相关；通过程序控制射频信号，就可以控制光谱。利用设计的光谱成像原理样机进行了地基月球观测实验。基于实验的特点，在光学设计的基础上增加了另一路共轴辅助光学，以进行粗定位。在获取成像结果之后，进行了辐射定标和尺度不变特征变换(Scale Invariant Feature Transformation, SIFT)图像拼接处理。结果表明，利用二维指向机构和面阵凝视成像系统，结合SIFT图像拼接算法，可有效获取宽幅高分辨率光谱图像。

AOTF Imaging Spectrometer Based on Staring/scanning Area Array Detector and Its Image Stitching Test

A visible and near infrared imaging spectrometer is one of the important parts for spectral detection. According to the actual application requirements of a ground-based visible and near infrared imaging spectrometer, a staring/scanning imaging spectrometer using an area array detector is proposed. The spectrometer also employs a new light splitting device-an Accousto-optical Tunable Filter (AOTF). It has a feature that the selection of spectrum is related to the frequency of the RF signal applied to it. By controlling the RF signal via a program, the spectrum can be controlled. A ground-based lunar observation experiment is carried out with the imaging spectrometer prototype designed. According to the experimental characteristics, another auxiliary coaxial optics is added for rough positioning on the basis of optical design. After the imaging results are acquired, radiometric calibration and SIFT image stitching are implemented. The results show that by combining a two-dimensional pointing mechanism and a staring imaging system with the SIFT image stitching algorithm, wide width high resolution spectral images can be acquired effectively.