The nature of the fiber noise with the FOCES spectrograph. Nature, modeling and a way to achieve S/N > 400
The nature of the fiber noise with the FOCES spectrograph. Nature, modeling and a way to achieve S/N > 400
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DOI：
10.1051/0004-6361:20031432
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发表时间：
2003-12
影响因子：
6.5
通讯作者：
F. Grupp
中科院分区：
文献类型：
--
作者：
F. Grupp
使用光纤馈送的F-偏振光谱仪注意到的非白噪声被认为是光纤出口后面的光谱仪光束中单色光的不均匀分布的渐晕的结果。这种现象-可以分配给每一个光纤耦合摄谱仪与光纤后面的光路渐晕-定性和定量描述和建模。当通过两次平场曝光围绕物体曝光时，S /N比似乎被限制在200以下，这表明S/N比达到了S /N 500的理论极限（由CCD检测器的线性范围定义）。这是通过使用多个平场曝光与光纤振动装置相结合来实现的，所述光纤振动装置允许光纤在曝光时间期间的非谐波运动。
The non-white noise noticed using the fiber-fed F spectrograph is recognized as the result of vignetting to an uneven distribution of monochromatic light in the spectrograph beam behind the fiber exit. This phenomenon - that can be assigned toevery fiber-coupled spectrograph with vignetting of the light path behind the fiber - is qualitatively and quantitatively described and modeled. The S /N ratio that seemed to be limited to ≈200 when surrounding the object exposure by two flatfield exposures is shown to reach the theoretical limit (defined by the linear range of the CCD-detector) of S /N ≈ 500. This is achieved by using multiple flatfield exposures in combination with a fiber vibration device allowing non-harmonic movement of the fiber during exposure time.