Wang Zhipeng, Tyo J Scott, Hayat Majeed M
College of Optical Sciences, University of Arizona, Tucson, AZ 85721, USA.
J Opt Soc Am A Opt Image Sci Vis. 2008 Oct;25(10):2528-34. doi: 10.1364/josaa.25.002528.
Traditional spectral sensors are intentionally designed to minimize overlap among spectral response functions of different bands. In contrast, some emerging classes of spectral sensors exhibit significant band overlap. An effect introduced by such band overlap is that the photodetector noise of one band is coupled into the others in subsequent data processing steps. Because of this, the traditional band-by-band definition of signal-to-noise ratio (SNR) cannot fully describe the detector's noise level. We devise a general definition of SNR in spectral space based on a recently developed geometrical spectral imaging model [J. Opt. Soc. Am. A24, 2864 (2007)]. With this model, we can find an orthogonal basis of the spectral response functions for the spectral sensor with decreasing instrument SNRs. We can also define the average instrument SNR for the whole sensor, which makes it possible to characterize quantitatively the photodetector noise of a spectral sensor with correlated bands.
传统光谱传感器的设计初衷是尽量减少不同波段光谱响应函数之间的重叠。相比之下，一些新兴的光谱传感器类别呈现出显著的波段重叠。这种波段重叠所带来的一个影响是，在后续的数据处理步骤中，一个波段的光电探测器噪声会耦合到其他波段。因此，传统的逐个波段定义的信噪比（SNR）无法完全描述探测器的噪声水平。我们基于最近开发的几何光谱成像模型[《美国光学学会志A》24, 2864 (2007)]，在光谱空间中设计了一种信噪比通用定义。借助该模型，我们可以找到随着仪器信噪比降低的光谱传感器光谱响应函数的正交基。我们还可以定义整个传感器的平均仪器信噪比，这使得定量表征具有相关波段的光谱传感器的光电探测器噪声成为可能。
