The spectrum of gaseous methane at 77 K in the 1.1 – 2.6 μm region: a benchmark for planetary astronomy

1989 ◽  
Vol 67 (11) ◽  
pp. 1027-1035 ◽  
Author(s):  
A. R. W. McKellar
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Low Temperature ◽  
Spectral Resolution ◽  
Fourier Transform Spectrometer ◽  
Absorption Cell ◽  
Model Calculations ◽  
Testing Model ◽  
Medium Resolution ◽  
Spectrometer Data

The spectrum of CH4 obtained in CH4 plus N2 mixtures at a temperature of 77 K has been recorded with a spectral resolution of 0.14 cm−1 in the region 3800 to 9100 cm−1. The experiments were performed with long paths (66 or 88 m) in a cooled absorption cell using a Fourier-transform spectrometer. Data are presented here at low and medium resolution, and examples of some spectral regions are also shown at high resolution. The complete results are available from the author in an Appendix. Comparisons are made with previous model calculations of CH4 absorption, and with the observed spectrum of Neptune's satellite, Triton. The results should be useful for the interpretation of the spectra of Triton, Titan, and Pluto. They will also be of value for testing model calculations of low-temperature CH4 absorption, which, thus verified, can be used with greater confidence to analyze observations of Jupiter, Saturn Uranus, and Neptune.

Algorithmic Enhancement of Spectral Resolution of a Lithium Niobate (LiNbO3) Waveguide-Based Miniature Fourier Transform Spectrometer

2016 ◽  
Vol 70 (10) ◽  
pp. 1685-1691 ◽  
Author(s):  
Kun Wang ◽  
Jinyang Li ◽  
Dan-feng Lu ◽  
Zhi-mei Qi
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Spectral Resolution ◽  
Linear Prediction ◽  
Resolution Enhancement ◽  
Fold Increase ◽  
Laser Wavelength ◽  
Ar Model ◽  
Fourier Transform Spectrometer ◽  
Value Decomposition

In a recent report we demonstrated a miniature static Fourier transform spectrometer (FTS) that was implemented with a LiNbO3 (LN) waveguide electro-optic modulator (EOM) combined with the dispersion relation between its half-wave voltage and wavelength. The FTS was verified to be able to measure laser wavelength and for low-resolution spectroscopy. In this report, we successfully applied the resolution enhancement algorithm to the FTS, resulting in at least a three-fold increase in its spectral resolution without causing obvious distortion of the measured spectra. The algorithm method used is based on an autoregressive (AR) model, singular value decomposition (SVD), and forward–backward linear prediction (FBLP). The combination of these methods allows the FTS to remain a small size but to possess good spectral resolution, effectively mitigating the conflict between the small size and high resolution of the device. This study opens the way to development of high-resolution miniature FTS.

scholarly journals Analysis of new species retrieved from MIPAS

2014 ◽  
Vol 56 ◽  
Author(s):  
Shaomin Cai ◽  
Anu Dudhia
Keyword(s):  
Fourier Transform ◽  
New Species ◽  
High Resolution ◽  
Trace Gases ◽  
Michelson Interferometer ◽  
Emission Spectra ◽  
Fourier Transform Spectrometer ◽  
Mid Infrared ◽  
The Third ◽  
Atmospheric Sounding

The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument which operated on the Envisat satellite from 2002-2012 is a Fourier transform spectrometer for the measurement of high-resolution gaseous emission spectra at the Earth's limb. It operates in the near- to mid-infrared, where many of the main atmospheric trace gases have important emission features. The initial operational products were profiles of Temperature, H2O, O3, CH4, N2O, HNO3, and NO2, and this list was recently extended to include N2O5, ClONO2, CFC-11 and CFC-12. Here we present preliminary results of retrievals of the third set of species under consideration for inclusion in the operational processor: HCN, CF4, HCFC-22, COF2 and CCl4.

scholarly journals Medium Resolution Spectroscopy at 1-2 Microns

1979 ◽  
Vol 47 ◽  
pp. 239-246
Author(s):  
J. R. Mould
Keyword(s):  
Fourier Transform ◽  
Main Sequence ◽  
Classification Criteria ◽  
Fourier Transform Spectrometer ◽  
Main Sequence Stars ◽  
Composite Spectra ◽  
Medium Resolution ◽  
M Stars

AbstractThe need for establishing classification criteria at long wavelengths is stressed. The usefulness of doing this is illustrated with a discussion of the composite spectra of FU Orionis stars. Spectra of these pre-main-sequence stars from 1.5-2.5μ were obtained with a Fourier Transform Spectrometer. Luminosity criteria in the l-2μ range are also discussed with application to M stars.

Far-infrared high-resolution Fourier transform spectrometer

1987 ◽  
Vol 26 (18) ◽  
pp. 3818 ◽  
Author(s):  
Bruno Carli ◽  
Massimo Carlotti ◽  
Francesco Mencaraglia ◽  
Enzo Rossi
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Far Infrared ◽  
Fourier Transform Spectrometer

Is the Moon the future of infrared astronomy?

2020 ◽  
Vol 379 (2188) ◽  
pp. 20200212 ◽  
Author(s):  
Jean-Pierre Maillard
Keyword(s):  
Spectral Analysis ◽  
Fourier Transform ◽  
Low Temperature ◽  
Infrared Astronomy ◽  
Fourier Transform Spectrometer ◽  
The Moon ◽  
Large Telescope ◽  
Microwave Background ◽  
Low Gravity ◽  
Fundamental Goal

Infrared astronomy, particularly in spectroscopy, could benefit in a decisive way from an implementation of telescopes on the Moon since the largest telescopes on Earth are practically limited to 40 m and in space to 10 m. On the Moon, a collector larger than on Earth becomes conceivable, thanks to the low gravity and the absence of wind, in having the advantages of space. Passively cooled in the bottom of a permanently shadowed crater at the northern or the southern pole, it could reach unprecedented spectral sensitivity on a large part of the infrared domain, making possible spectral analysis of the most primitive galaxies and of the terrestrial exoplanet atmospheres. A project aiming at the detection of the weak cosmic microwave background spectral distortions is also presented. Several identical 1.5 m cryo-cooled telescopes at 2.5 K to fit in a launcher, with an imaging Fourier transform spectrometer in each unit, deposited in a cold crater and pointing in the same direction in lunar survey mode, would build for this fundamental goal the equivalent of a large telescope at an extremely low temperature. Last, the feasibility of these projects is discussed. This article is part of a discussion meeting issue ‘Astronomy from the Moon: the next decades'.

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