scholarly journals Analysis of the Interference Modulation Depth in the Fourier Transform Spectrometer

2015 ◽  
Vol 2015 ◽  
pp. 1-4 ◽  
Author(s):  
Rilong Liu
Keyword(s):  
Fourier Transform ◽  
Modulation Depth ◽  
Michelson Interferometer ◽  
Surface Shape ◽  
Fourier Transform Spectrometer ◽  
Shape Error ◽  
Paper Briefly ◽  
Interference Modulation ◽  
Reflectance Change ◽  
The Fourier Transform

Based on the principle of the Michelson interferometer, the paper briefly describes the theoretical significance and calculates and deduces three expressions of the interference modulation depth. The influence of the surface shape error of plane mirror on modulation depth is analyzed, and the tolerance of error is also pointed out. Moreover, the dependence of modulation depth on the reflectance change of beam splitter interface is also analyzed, and the curve is given. It is concluded that this paper is of general significance for the Fourier transform spectrometer based on the principle of the Michelson two-beam interference.

scholarly journals Experiments on the Porch Swing Bearing of Michelson Interferometer for Low Resolution FTIR

2013 ◽  
Vol 2013 ◽  
pp. 1-9
Author(s):  
Tuomas Välikylä ◽  
Jyrki Kauppinen
Keyword(s):  
Fourier Transform ◽  
Laser Beam ◽  
Modulation Depth ◽  
Michelson Interferometer ◽  
Fourier Transform Spectrometer ◽  
Linear Motion ◽  
Low Resolution ◽  
Mid Infrared ◽  
Manufacturing Tolerances ◽  
Adjustment Mechanisms

Porch swing bearing for the linear motion of the mirror in Michelson interferometer for mid-infrared low resolution Fourier transform spectrometer was studied experimentally using the modulation depth of the collimated laser beam. The mirror tilting was measured to be lower than 5 μrad over 3 mm mirror travel using two different bearings assemblies. Additionally, the manufacturing tolerances of the bearing type were proved to be loose enough not to limit the interferometer application. These demonstrate that the porch swing without any adjustment mechanisms provides the sufficient motion linearity.

The infrared spectrum of CS

1984 ◽  
Vol 62 (12) ◽  
pp. 1414-1419 ◽  
Author(s):  
R. J. Winkel Jr. ◽  
Sumner P. Davis ◽  
Rubén Pecyner ◽  
James W. Brault
Keyword(s):  
Fourier Transform ◽  
Infrared Emission ◽  
Solar Observatory ◽  
Band Head ◽  
The Other ◽  
Fourier Transform Spectrometer ◽  
National Solar Observatory ◽  
Carbon Monosulfide ◽  
Vibration Rotation ◽  
The Fourier Transform

The infrared emission spectrum of carbon monosulfide was observed as a sequence of vibration–rotation bands in the X1Σ+ state, with strong heads of the Δν = 2 sequence degraded to the red. Eight bands of 12C32S were identified, and bands corresponding to the isotope 12C34S were also observed. The most prominent band head, that of the (2–0) band, is at 2585 cm−1, with the other heads spaced approximately 26 cm−1 to smaller wavenumbers. Our data, taken with the Fourier transform spectrometer at the National Solar Observatory (Kitt Peak) include the first reported laboratory observations of the band heads and as many as 200 lines in each band. These observations allowed the calculation of vibrational and rotational constants to higher order than previously reported.

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.

Balloon-borne GLORIA hyperspectral Limb and Nadir imager in the LWIR

2021 ◽  
Author(s):  
Erik Kretschmer ◽  
Felix Friedl-Vallon ◽  
Thomas Gulde ◽  
Michael Höpfner ◽  
Sören Johansson ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Optical System ◽  
Late Summer ◽  
High Spectral Resolution ◽  
Fourier Transform Spectrometer ◽  
System Improvement ◽  
The Fourier Transform ◽  
Temperature Retrieval ◽  
Long Wave Infrared ◽  
Better Than

<p>The GLORIA-B (Gimballed Limb Observer for Radiance Imaging of the Atmosphere - Balloon) instrument is an adaptation of the very successful GLORIA-AB imaging Fourier transform spectrometer (iFTS) flown on the research aircrafts HALO and M55 Geophysica. The high spectral resolution in the LWIR (Long Wave Infrared) allows for the retrieval of temperature and of a broad range of atmospheric trace gases, with the goal to retrieve O<sub>3</sub>, H<sub>2</sub>O, HNO<sub>3</sub>, C<sub>2</sub>H<sub>6</sub>, C<sub>2</sub>H<sub>2</sub>, HCOOH, CCl<sub>4</sub>, PAN, ClONO<sub>2</sub>, CFC-11, CFC-12, SF<sub>6</sub>, OCS, NH<sub>3</sub>, HCN, BrONO<sub>2</sub>, HO<sub>2</sub>NO<sub>2</sub>, N<sub>2</sub>O<sub>5</sub> and NO<sub>2</sub>. The radiometric sensitivity of the Balloon instrument is further increased in comparison with the GLORIA-AB instrument by having two detector channels on the same focal plane array, while keeping the same concept of a cooled optical system. This system improvement was achieved with minimal adaptation of the existing optical system.</p><p>The high spatial and temporal resolution of the instrument is ensured by the imaging capability of the Fourier transform spectrometer while stabilizing the line-of-sight in elevation with the instrument and in azimuth with the balloon gondola. In a single measurement lasting 13 seconds, the atmosphere can be sounded from mid-troposphere up to flight altitude, typically 30 km, with a vertical resolution always better than 1 km for most retrieved species; a spatial resolution up to 0.3 km can be achieved in favourable conditions. Temperature retrieval precision between 0.1 and 0.2 K is expected. A spectral sampling up to 0.0625 cm<sup>-1</sup> can be achieved.</p><p>The first flight of GLORIA-B shall take place during the late-summer polar jet turn-around at Kiruna/ESRANGE. This flight is organised in the frame of the HEMERA project and was scheduled for summer 2020, but was ultimately postponed to summer 2021. Beyond qualification of the first balloon-borne iFTS, the scientific goals of the flight are, among others, the quantification of the stratospheric bromine budget and its diurnal evolution by measuring vertical profiles of BrONO<sub>2 </sub>in combination with BrO observations by the DOAS instrument of University Heidelberg on the same platform.</p>

scholarly journals Intensity Simulation of a Fourier Transform Infrared Spectrometer

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1833 ◽  
Author(s):  
Zhuoya Ni ◽  
Qifeng Lu ◽  
Yishu Xu ◽  
Hongyuan Huo
Keyword(s):  
Fourier Transform ◽  
Brightness Temperature ◽  
Michelson Interferometer ◽  
Fourier Transform Infrared ◽  
Core Element ◽  
Simulation Process ◽  
Fourier Transform Infrared Spectrometer ◽  
Infrared Spectrometer ◽  
Input Spectrum ◽  
The Fourier Transform

This paper introduces an intensity simulation for the Fourier transform infrared spectrometer whose core element is the Michelson interferometer to provide support for the on-orbit monitoring of the instrument and to improve the data processing and application of the Fourier transform spectrometer. The Geostationary Interferometric Infrared Imager (GIIRS) aboard on Fengyun-4B (FY-4B) satellite, which will be launched in 2020, aims to provide hyperspectral infrared observations. An intensity simulation of the Michelson interferometer based on the GIIRS’s instrument parameters is systematically analyzed in this paper. Off-axis effects and non-linearity response are two important factors to be considered in this simulation. Off-axis effects mainly cause the wavenumber shift to induce a large brightness temperature error compared with the input spectrum, and the non-linearity response reduces the energy received by the detector. Then, off-axis effects and a non-linearity response are added to the input spectrum successively to obtain the final spectrum. Off-axis correction and non-linearity correction are also developed to give a full simulation process. Comparing the corrected spectrum with the input spectrum, we can see that the brightness temperature errors have a magnitude of 10−3 K, and this fully proves the reliability and rationality of the whole simulation process.

Lambda doubling in the infrared spectrum of SH

1984 ◽  
Vol 62 (12) ◽  
pp. 1420-1425 ◽  
Author(s):  
R. J. Winkel Jr. ◽  
Sumner P. Davis
Keyword(s):  
Fourier Transform ◽  
Infrared Spectrum ◽  
Ground State ◽  
Solar Observatory ◽  
Fourier Transform Spectrometer ◽  
Multiplet Splitting ◽  
National Solar Observatory ◽  
Vibration Rotation ◽  
The Fourier Transform ◽  
First Time

The (1–0), (2–1), and (3–2) infrared vibration–rotation bands of the X2Π ground state of sulfur monohydride were observed in emission from a furnace. Multiplet splitting produces two subbands, each of which exhibits lambda splitting. The band heads were observed for the first time, 285 lines were measured, and a calculation of lambda-doubling parameters was made. The spectrum was recorded using the Fourier transform spectrometer at the National Solar Observatory (Kitt Peak).

scholarly journals Global distribution of upper tropospheric formic acid from the ACE-FTS

2009 ◽  
Vol 9 (20) ◽  
pp. 8039-8047 ◽  
Author(s):  
G. González Abad ◽  
P. F. Bernath ◽  
C. D. Boone ◽  
S. D. McLeod ◽  
G. L. Manney ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Formic Acid ◽  
Atmospheric Chemistry ◽  
South American ◽  
Fourier Transform Spectrometer ◽  
Vegetation Growth ◽  
Solar Occultation ◽  
The Fourier Transform ◽  
Chemistry Experiment ◽  
Seasonal Dependence

Abstract. We present the first near global upper tropospheric distribution of formic acid (HCOOH) observed from space using solar occultation measurements from the Fourier transform spectrometer (FTS) on board the Atmospheric Chemistry Experiment (ACE) satellite. Using a new set of spectroscopic line parameters recently published for formic acid by Vander Auwera et al. (2007) and Perrin and Vander Auwera (2007), we have retrieved the concentrations of HCOOH between 5 km and the tropopause for ACE-FTS observations from February 2004 to September 2007. We observe a significant seasonal dependence for the HCOOH concentrations related to vegetation growth and biomass burning. We estimate an emission ratio of 0.0051±0.0015 for HCOOH relative to CO for tropical South American fires using a selected set of data for September 2004. Results from the balloon-borne MkIV Fourier transform spectrometer are also presented and compared with the ACE measurements.

The Fourier transform spectrometer of the Université Pierre et Marie Curie QualAir platform

2010 ◽  
Vol 81 (10) ◽  
pp. 103102 ◽  
Author(s):  
Y. Té ◽  
P. Jeseck ◽  
S. Payan ◽  
I. Pépin ◽  
C. Camy-Peyret
Keyword(s):  
Fourier Transform ◽  
Fourier Transform Spectrometer ◽  
Marie Curie ◽  
The Fourier Transform

A Fourier-transform spectrometer for infra-red cathodoluminescence in TEM

1983 ◽  
Vol 41 ◽  
pp. 128-129
Author(s):  
J.C.H. Spence ◽  
J. Isenman
Keyword(s):  
Electronic Structure ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Design Problem ◽  
Michelson Interferometer ◽  
Fourier Transform Spectrometer ◽  
Extended Defects ◽  
Infra Red ◽  
Mirror Movement ◽  
Defects In Semiconductors

The study of the electronic structure of deep states associated with isolated, well characterised extended defects in semiconductors requires the use of a cathodoluminescence apparatus for TEM in the wavelength range 1-50 microns (1.2 - 0.02 eV). This would also allow the study of the III-V alloys and their defects used for I.R. emitters and lasers. Preliminary results using a grating spectrometer have been obtained by Petroff, however experience from Astronomy indicates that the Fellgett + Jacquinot advantage obtainable using Fourier Transform Infrared Spectroscopy (F.T.I.R.S.) is important for weak sources and noisy detectors. (See Davidson who has compared both techniques in SEM).The crucial design problem in the 1-10 micron range is the mirror movement in the Michelson Interferometer, which must be reproduceably positioned with submicron accuracy over a one centimeter range.

Nonlinear effects of the Fourier transform spectrometer detector and its correction

2017 ◽  
Vol 46 (10) ◽  
pp. 1023001
Author(s):  
杨敏珠 Yang Minzhu ◽  
邹曜璞 Zou Yaopu ◽  
张 磊 Zhang Lei ◽  
韩昌佩 Han Changpei
Keyword(s):  
Fourier Transform ◽  
Nonlinear Effects ◽  
Fourier Transform Spectrometer ◽  
The Fourier Transform
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