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Slit Function Measurement of An Imaging Spectrograph Using Fourier Transform TechniquesKnowledge of a spectrograph slit function is necessary to interpret the unresolved lines in an observed spectrum. A theoretical slit function can be calculated from the sizes of the entrance slit, the detector aperture when it functions as an exit slit, the dispersion characteristic of the disperser, and the point spread function of the spectrograph. A measured slit function is preferred to the theoretical one for the correct interpretation of the spectral data. In a scanning spectrometer with a single exit slit, the slit function is easily measured. In a fixed grating/or disperser spectrograph, illuminating the entrance slit with a near monochromatic light from a pre-monochrmator or a tunable laser and varying the wavelength of the incident light can measure the slit function. Even though the latter technique had been used successfully for the slit function measurements, it had been very laborious and it would be prohibitive to an imaging spectrograph or a multi-object spectrograph that has a large field of view. We explore an alternative technique that is manageable for the measurements. In the proposed technique, the imaging spectrograph is used as a detector of a Fourier transform spectrometer. This method can be applied not only to an IR spectrograph but also has a potential to a visible/UV spectrograph including a wedge filter spectrograph. This technique will require a blackbody source of known temperature and a bolometer to characterize the interferometer part of the Fourier Transform spectrometer. This pa?er will describe the alternative slit function measurement technique using a Fourier transform spectrometer.
Document ID
20040084069
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Authors
Park, Hongwoo
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Swimyard, Bruce
(Rutherford Appleton Lab. United Kingdom)
Jakobsen, Peter
(European Space Agency Unknown)
Moseley, Harvey
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Greenhouse, Matthew
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 21, 2013
Publication Date
January 1, 2004
Subject Category
Spacecraft Instrumentation And Astrionics
Meeting Information
Meeting: SPIE Astronomical Telescope and Instrumentations
Country: Unknown
Start Date: June 21, 2004
End Date: June 25, 2004
Sponsors: International Society for Optical Engineering
Distribution Limits
Public
Copyright
Other

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