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Throughput of the Composite Infrared Spectrometer (CIRS) Mid Infrared (MIR) Channel for the Cassini Mission to SaturnThe Composite Infrared Spectrometer (CIRS) of the Cassini mission to Saturn has two interferometers covering the far infrared and mid infrared wavelength region. The instrument was aligned at ambient temperature, but operates at 170 Kelvin and has challenging interferometric alignment tolerances. Cryogenic alignment tests of the instrument indicate that it should suffer minimal degradation due to the cooldown from ambient to operational temperature. System level tests performed by the calibration team indicated a lower than expected signal level on the MIR channel, while providing ambiguous optical throughput data. Therefore it became imperative to develop a metric that could be used to determine the instrument performance at both the instrument and system levels, at ambient and cryogenic temperature. Modulation efficiency and throughput measurements were performed and new analytical models developed to evaluate the status of the instrument. Empirical and analytical data were eventually reconciled and deviations from the design values explained.
Document ID
19990067633
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
Authors
Hagopian, John G.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Losch, Patricia
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Stewart, Kenneth P.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Jennings, Donald
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Martino, Anthony J.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Date Acquired
August 19, 2013
Publication Date
January 1, 1998
Subject Category
Lunar And Planetary Exploration
Meeting Information
Meeting: Cryogenic Optical Systems and Instruments VIII
Location: San Diego, CA
Country: United States
Start Date: July 19, 1998
End Date: July 24, 1998
Sponsors: International Society for Optical Engineering
Distribution Limits
Public
Copyright
Other

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