空间调制干涉型和衍射光栅型成像光谱仪信噪比性能的分析比较

Analysis and Comparison of Signal-to-Noise Ratio of Spatially Modulated Interference and Diffraction Grating Imaging Spectrometers

以Sagnac空间调制干涉型成像光谱仪和Offner凸面光栅衍射型成像光谱仪为例,着重分析和比较这两类成像光谱仪的信噪比性能。在相同观测条件下,通过推导这两类成像光谱仪所得到的图像像元的光谱辐亮度,指出空间调制干涉型成像光谱仪并不具有高通量和多路复用优势,信噪比也低于衍射光栅成像光谱仪。而且随着光谱谱段数的增加,即光谱分辨率的提高,衍射光栅成像光谱仪的信噪比优势更明显。

Sagnac spatially-modulated interference imaging spectrometer and Offner convex diffraction grating imaging spectrometer are focused on, and their signal-to-noise performance is seriously analyzed. Through derivation of the spectral radiance of their acquired image pixels under same observation condition, it is shown that spatially-modulated interference imaging spectrometer no longer has high throughput and multiplex advantages so that its signal-to-noise is lower than diffraction grating imaging spectrometer. Further, the latter＇ s signal-to- noise ratio advantage becomes more significant as the increase of spectral band number.