EXES: The Echelon-cross-echelle Spectrograph for SOFIA

2018 ◽  
Vol 07 (04) ◽  
pp. 1840013 ◽  
Author(s):  
M. J. Richter ◽  
C. N. DeWitt ◽  
M. McKelvey ◽  
E. Montiel ◽  
R. McMurray ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Infrared Astronomy ◽  
High Spectral Resolution ◽  
Echelle Spectrograph ◽  
Mid Infrared ◽  
Low Background ◽  
And Performance ◽  
Operational Modes ◽  
Echelon Grating

The Echelon-cross-echelle spectrograph (EXES) is a high spectral resolution, mid-infrared spectrograph designed for and operated on the Stratospheric Observatory for Infrared Astronomy (SOFIA). EXES has multiple operational modes, but is optimized for high spectral resolution. The heart of the instrument is a one meter long, diamond-machined echelon grating. EXES also uses a 10242 Si:As detector optimized for low-background flux. We will discuss the design, operation and performance of EXES.

scholarly journals Time-resolved mid-infrared dual-comb spectroscopy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Muhammad A. Abbas ◽  
Qing Pan ◽  
Julien Mandon ◽  
Simona M. Cristescu ◽  
Frans J. M. Harren ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Vibrational Excitation ◽  
High Spectral Resolution ◽  
Acquisition Time ◽  
Time Resolved ◽  
Short Acquisition Time ◽  
Mid Infrared ◽  
Infrared Wavelength ◽  
Potential Applications ◽  
Kinetics Of

AbstractDual-comb spectroscopy can provide broad spectral bandwidth and high spectral resolution in a short acquisition time, enabling time-resolved measurements. Specifically, spectroscopy in the mid-infrared wavelength range is of particular interest, since most of the molecules have their strongest rotational-vibrational transitions in this “fingerprint” region. Here we report time-resolved mid-infrared dual-comb spectroscopy, covering ~300 nm bandwidth around 3.3 μm with 6 GHz spectral resolution and 20 μs temporal resolution. As a demonstration, we study a CH4/He gas mixture in an electric discharge, while the discharge is modulated between dark and glow regimes. We simultaneously monitor the production of C2H6 and the vibrational excitation of CH4 molecules, observing the dynamics of both processes. This approach to broadband, high-resolution, and time-resolved mid-infrared spectroscopy provides a new tool for monitoring the kinetics of fast chemical reactions, with potential applications in various fields such as physical chemistry and plasma/combustion analysis.

scholarly journals Hybrid high spectral resolution broadband mid-infrared SFG spectrometer development and demonstration

2021 ◽  
Author(s):  
Karolis Madeikis ◽  
Robertas Kananavicius ◽  
Rokas Danilevicius ◽  
Audrius Zaukevicius ◽  
Januskevicius Regimantas ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
High Spectral Resolution ◽  
Mid Infrared

scholarly journals High-Resolution Infrared Far-IR Spectroscopy from SOFIA, 2005-2025

2005 ◽  
Vol 13 ◽  
pp. 818-821
Author(s):  
J. A. Davidson ◽  
E. F. Erickson
Keyword(s):  
High Resolution ◽  
Ir Spectroscopy ◽  
Wavelength Range ◽  
Spectral Resolution ◽  
Lower Stratosphere ◽  
Infrared Astronomy ◽  
High Spectral Resolution ◽  
Science Program ◽  
Absorption And Emission ◽  
Operational Lifetime

NASA and the DLR are developing SOFIA, the Stratospheric Observatory for Infrared Astronomy: a 2.5 m telescope in a Boeing 747SP aircraft. By flying in the lower stratosphere, SOFIA will allow astronomical measurements covering the wavelength range from 0.3 μm to 1.6 mm, with an emphasis on the spectral regions inaccessible from the ground, particularly the 6-8 μm and 30-300 μm regions. SOFIA will see “first light” in 2004; the science program will start in 2005. An operational lifetime of 20 years is planned.SOFIA will support a diverse and evolving complement of state-of-theart science instruments. Its spectrometers will have resolutions ranging from ~ 108 down to ~ 100, as needed to measure absorption and emission from astrophysically significant atoms, ions, molecules, aerosols, and solids. This paper describes the spectrometers being developed to fly on SOFIA soon after first light, and summarizes some of the high-spectral resolution investigations expected.

scholarly journals Mid-infrared interferometry with high spectral resolution

2010 ◽  
Author(s):  
Edward H. Wishnow ◽  
William Mallard ◽  
Vikram Ravi ◽  
Sean Lockwood ◽  
Walt Fitelson ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
High Spectral Resolution ◽  
Mid Infrared ◽  
Infrared Interferometry

scholarly journals The New Coudé Échelle Spectrograph for the Anglo Australian Telescope

1984 ◽  
Vol 79 ◽  
pp. 499-513
Author(s):  
David D. Walker ◽  
Francisco Diego
Keyword(s):  
Advisory Committee ◽  
Optical System ◽  
Spectral Resolution ◽  
Mechanical Design ◽  
Complete System ◽  
High Spectral Resolution ◽  
Advanced Stage ◽  
Echelle Spectrograph ◽  
University College ◽  
University College London

During 1983, the advisory committee for instrumentation at the Anglo Australian Telescope (AAT) recommended that, as a matter of high priority, an échelle spectrograph should be procured for the f/36 coudé focus. The aim was to satisfy the high spectral-resolution needs of the community which, hereto, have been neglected. We at University College London (UCL) were invited to consider the design and our proposal was subsequently accepted by the Board. We are now at an advanced stage in optimizing the optical system, and mechanical design is proceeding. We plan to test the complete system in the laboratory at UCL prior to installation and commissioning at the AAT which we anticipate will be during 1987.

scholarly journals Rotational temperature of N<sub>2</sub><sup>+</sup> (0,2) ions from spectrographic measurements used to infer the energy of precipitation in different auroral forms and compared with radar measurements

2008 ◽  
Vol 26 (4) ◽  
pp. 853-866 ◽  
Author(s):  
O. Jokiaho ◽  
B. S. Lanchester ◽  
N. Ivchenko ◽  
G. J. Daniell ◽  
L. C. H. Miller ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Molecular Spectroscopy ◽  
Rotational Temperature ◽  
Average Energy ◽  
High Spectral Resolution ◽  
High Time Resolution ◽  
Echelle Spectrograph ◽  
Characteristic Energy ◽  
Neutral Temperature ◽  
Magnetic Zenith

Abstract. High resolution spectral data are used to estimate neutral temperatures at auroral heights. The data are from the High Throughput Imaging Echelle Spectrograph (HiTIES) which forms part of the Spectrographic Imaging Facility (SIF), located at Longyearbyen, Svalbard in Norway. The platform also contains photometers and a narrow angle auroral imager. Quantum molecular spectroscopy is used for modelling N2+ 1NG (0,2), which serves as a diagnostic tool for neutral temperature and emission height variations. The theoretical spectra are convolved with the instrument function and fitted to measured rotational transition lines as a function of temperature. Measurements were made in the magnetic zenith, and along a meridian slit centred on the magnetic zenith. In the results described, the high spectral resolution of the data (0.08 nm) allows an error analysis to be performed more thoroughly than previous findings, with particular attention paid to the correct subtraction of background, and to precise wavelength calibration. Supporting measurements were made with the Svalbard Eiscat Radar (ESR). Estimates were made from both optical and radar observations of the average energy of precipitating electrons in different types of aurora. These provide confirmation that the spectral results are in agreement with the variations observed in radar profiles. In rayed aurora the neutral temperature was highest (800 K) and the energy lowest (1 keV). In a bright curling arc, the temperature at the lower border was about 550 K, corresponding to energies of 2 keV. The radar and modelling results confirm that these average values are a lower limit for an estimation of the characteristic energy. In each event the energy distribution is clearly made up of more than one spectral shape. This work emphasises the need for high time resolution as well as high spectral resolution. The present work is the first to provide rotational temperatures using a method which pays particular attention to errors in measurement and fitting, and background subtraction.

scholarly journals Cloud identification and classification from high spectral resolution data in the far and mid infrared

2019 ◽  
Author(s):  
Tiziano Maestri ◽  
William Cossich ◽  
Iacopo Sbrolli
Keyword(s):  
Spectral Resolution ◽  
Learning Algorithm ◽  
Far Infrared ◽  
Synthetic Dataset ◽  
High Spectral Resolution ◽  
Spectral Radiance ◽  
Electromagnetic Spectrum ◽  
Cloud Detection ◽  
Mid Infrared ◽  
Univariate Distribution

Abstract. A new Cloud Identification and Classification algorithm, named CIC, is presented. CIC is a machine-learning algorithm, based on Principal Component Analysis, able to perform a cloud detection and scene classification using a univariate distribution and a threshold, which serves as a binary classifier. CIC is tested on a widespread synthetic dataset of high spectral resolution radiances in the far and mid infrared part of the spectrum simulating measures from the ESA Earth Explorer Fast Track 9 competing mission FORUM (Far Infrared Outgoing Radiation Understanding and Monitoring) that is currently (2018/19) undergoing the industrial and scientific Phase-A studies. Simulated spectra are representatives of many diverse climatic areas, ranging from the tropical to polar regions. Application of the algorithm to the synthetic dataset provides high scores for clear/cloud identification, especially when optimisation processes are performed. One of the main results consists in pointing out the high information content of spectral radiance in the far-infrared region of the electromagnetic spectrum to identify cloudy scenes specifically thin cirrus clouds.

scholarly journals Exoplanet atmospheres at high spectral resolution: A CRIRES survey of hot-Jupiters

2010 ◽  
Vol 6 (S276) ◽  
pp. 208-211
Author(s):  
Ignas Snellen ◽  
Remco de Kok ◽  
Ernst de Mooij ◽  
Matteo Brogi ◽  
Bas Nefs ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Spectral Resolution ◽  
High Spectral Resolution ◽  
Mass Composition ◽  
Large Telescope ◽  
Test Bed ◽  
Echelle Spectrograph ◽  
Hot Jupiters ◽  
Transiting Planets ◽  
Very Large Telescope

AbstractRecently, we presented the detection of carbon monoxide in the transmission spectrum of extrasolar planet HD209458b, using CRIRES, the Cryogenic high-resolution Infrared Echelle Spectrograph at ESO's Very Large Telescope (VLT). The high spectral resolution observations (R=100,000) provide a wealth of information on the planet's orbit, mass, composition, and even on its atmospheric dynamics. The new observational strategy and data analysis techniques open up a whole world of opportunities. We therefore started an ESO large program using CRIRES to explore these, targeting both transiting and non-transiting planets in carbon monoxide, water vapour, and methane. Observations of the latter molecule will also serve as a test-bed for METIS, the proposed mid-infrared imager and spectrograph for the European Extremely Large Telescope.

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