title: Breadboard of a Fourier-transform spectrometer for the radiation explorer in the far infrared atmospheric mission.
abstract: In preparation for a possible space mission, a breadboard version named REFIR-BB of the Radiation Explorer in the Far Infrared (REFIR) instrument has been built. The REFIR is a Fourier-transform spectrometer with a new optical layout operating in the spectral range 100-1100 cm(-1) with a resolution of 0.5 cm(-1), a 7-s acquisition time, and a signal-to-noise ratio of better than 100. Its mission is the spectral measurement in the far infrared of the Earth's outgoing emission, with particular attention to the long-wavelength spectral region, which is not covered by either current or planned space missions. This measurement is of great importance for deriving an accurate estimate of the radiation budget in both clear and cloudy conditions. The REFIR-BB permits the trade-off among all instrument parameters to be studied, the optical layout to be tested, and the data-acquisition strategy to be optimized. The breadboard could be used for high-altitude ground-based campaigns or could be flown for test flights on aircraft or balloon stratospheric platforms. The breadboard's design and the experimental results are described, with particular attention to the acquisition strategy and characterization of the interferometer. Tests were performed both in laboratory conditions and in vacuum. Notwithstanding a loss of efficiency above 700 cm(-1) caused by the poor performance of the photolithographic polarizers used as beam splitters, the results demonstrate the feasibility of using the spectrometer for space applications.
authors.affiliation: Istituto di Fisica Applicata "Nello Carrara," Consigho Nazionale delle Ricerche, Via Panciatichi 64, 50127 Florence, Italy. l.palchetti@ifac.cnr.it
authors.forename: Luca
authors.initials: L
authors.lastname: Palchetti
authors.forename: Giovanni
authors.initials: G
authors.lastname: Bianchini
authors.forename: Francesco
authors.initials: F
authors.lastname: Castagnoli
authors.forename: Bruno
authors.initials: B
authors.lastname: Carli
authors.forename: Carmine
authors.initials: C
authors.lastname: Serio
authors.forename: Francesco
authors.initials: F
authors.lastname: Esposito
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Cuomo
authors.forename: Rolando
authors.initials: R
authors.lastname: Rizzi
authors.forename: Tiziano
authors.initials: T
authors.lastname: Maestri