High spectral resolution Fourier transform imaging spectroscopy in a Michelson interferometer with homodyne laser metrology control

2009 ◽  
Author(s):  
Mel Ni ◽  
Greg Feller ◽  
J. Wes Irwin ◽  
James Mason ◽  
Jason Mudge
Keyword(s):  
Fourier Transform ◽  
Spectral Resolution ◽  
Michelson Interferometer ◽  
Imaging Spectroscopy ◽  
High Spectral Resolution ◽  
Laser Metrology

Polarized high-spectral-resolution lidar based on field-widened Michelson interferometer

2016 ◽  
Author(s):  
Dong Liu ◽  
Zhongtao Cheng ◽  
Jing Luo ◽  
Yongying Yang ◽  
Yupeng Zhang ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Michelson Interferometer ◽  
High Spectral Resolution ◽  
High Spectral Resolution Lidar

Design of the High Spectral Resolution Lidar Filter Based on a Field-Widened Michelson Interferometer

2014 ◽  
Vol 41 (9) ◽  
pp. 0913003 ◽  
Author(s):  
黄寒璐 Huang Hanlu ◽  
刘东 Liu Dong ◽  
杨甬英 Yang Yongying ◽  
成中涛 Cheng Zhongtao ◽  
罗敬 Luo Jing ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Michelson Interferometer ◽  
High Spectral Resolution ◽  
High Spectral Resolution Lidar

scholarly journals Development of a 355-nm high-spectral-resolution lidar using a scanning Michelson interferometer for aerosol profile measurement

2020 ◽  
Vol 28 (16) ◽  
pp. 23209 ◽  
Author(s):  
Yoshitaka Jin ◽  
Tomoaki Nishizawa ◽  
Nobuo Sugimoto ◽  
Shoken Ishii ◽  
Makoto Aoki ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Michelson Interferometer ◽  
High Spectral Resolution ◽  
Profile Measurement ◽  
High Spectral Resolution Lidar

scholarly journals IMK/IAA MIPAS temperature retrieval version 8: nominal measurements

2020 ◽  
Author(s):  
Michael Kiefer ◽  
Thomas von Clarmann ◽  
Bernd Funke ◽  
Maya García-Comas ◽  
Norbert Glatthor ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Spectral Resolution ◽  
Spectroscopic Data ◽  
A Priori ◽  
Michelson Interferometer ◽  
High Spectral Resolution ◽  
Transfer Model ◽  
Random Component ◽  
Horizontal Structure ◽  
Total Uncertainty

Abstract. A new global set of atmospheric temperature profiles is retrieved from recalibrated radiance spectra recorded with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS). Changes with respect to previous data versions include a new radiometric calibration considering the time-dependency of the detector non-linearity, and a more robust frequency calibration scheme. Temperature is retrieved using a smoothing constraint, while tangent altitude pointing information is constrained using optimal estimation. ECMWF ERA-Interim is used as temperature a priori below 43 km. Above, a priori data is based on data from the Whole Atmosphere Community Climate Model Version 4 (WACCM4). Bias-corrected fields from specified dynamics runs, sampled at the MIPAS times and locations, are used, blended with ERA-Interim between 43 and 53 km. Horizontal variability of temperature is considered by scaling an a priori 3D temperature field in the orbit plane in a way that the horizontal structure is provided by the a priori while the vertical structure comes from the measurements. Additional microwindows with better sensitivity at higher altitudes are used. The background continuum is jointly fitted with the target parameters up to 58 km altitude. The radiance offset correction is strongly regularized towards an empirically determined vertical offset profile. In order to avoid the propagation of uncertainties of O3 and H2O a priori assumptions, the abundances of these species are retrieved jointly with temperature. The retrieval is based on HITRAN 2016 spectroscopic data, with a few amendments. Temperature-adjusted climatologies of vibrational populations of CO2 states emitting in the 15 micron region are used in the radiative transfer modelling in order to account for non-local thermodynamic equilibrium. Numerical integration in the radiative transfer model is now performed at higher accuracy. The random component of the temperature uncertainty typically varies between 0.4 and 0.8 K, with occasional excursions up to 1.3 K above 60 km altitude. The leading sources of the random component of the temperature error are measurement noise, gain calibration uncertainty, spectral shift, and uncertain CO2 mixing ratios. The systematic error is caused by uncertainties in spectroscopic data and line shape uncertainties. It ranges from 0.2 K at 24 km altitude for northern midlatitude nighttime conditions to 2.3 K at 12 km for tropical nighttime conditions. The estimated total uncertainty amounts to values between 0.5 K at 24 km and northern polar winter conditions to 2.3 K at 12 km and northern midlatitude day conditions. The vertical resolution varies around 3 km for altitudes below 50 km. The long-term drift encountered in the previous temperature product has been largely reduced. The consistency between high spectral resolution results from 2002–2004 and the reduced spectral resolution results from 2005–2012 has been largely improved. As expected, most pronounced temperature differences between version 8 and previous data versions are found in elevated stratopause situations. The fact that the phase of temperature waves seen by MIPAS is not locked to the wave phase found in ECMWF analyses demonstrates that our retrieval provides independent information and does not merely reproduce the prior information.

scholarly journals High-Resolution Fourier Transform Spectroscopy with a VLT

1984 ◽  
Vol 79 ◽  
pp. 497-497
Author(s):  
Donald N.B. Hall
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Spectral Resolution ◽  
Thermal Infrared ◽  
The Other ◽  
High Spectral Resolution ◽  
Resolution Element ◽  
Infrared Wavelengths ◽  
Frequency Calibration ◽  
Absorption Features

The major advantages of the FTS technique are (1) multiplexing, (2) throughput, (3) instrumental profile, (4) stability of frequency calibration, and (5) spectrophotometry accuracy. The multiplex advantage is realized only if one is detector noise limited for the signal within an individual spectral-resolution element. At optical and thermal infrared wavelengths, this is only the case at high spectral resolution (≥ 50000) for modern detectors. By the time the VLT is operating one expects this to also be the case in the 1- to 2.5-micron region. At resolutions ≥ 50000 there are severe problems matching dispersive spectrographs to the VLT aperture, whereas existing FTS instruments already have adequate through-put to match to fields of a few arcsec with a VLT. When the other advantages are considered, the FTS is the instrument of choice for high-resolution (≥ 50000) spectroscopy of absorption features with a VLT. Foreseeable astrophysical applications include observations of interstellar and circumstellar features and of fully resolved profiles of photospheric and planetary lines.

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