A precise high-resolution near infrared continuous wave cavity ringdown spectrometer using a Fourier transform based wavelength calibration

2010 ◽  
Vol 81 (5) ◽  
pp. 053109 ◽  
Author(s):  
Carsten Fehling ◽  
Gernot Friedrichs
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Near Infrared ◽  
Continuous Wave ◽  
Wavelength Calibration ◽  
Cavity Ringdown

scholarly journals High-resolution, non-scanning FTS for remote sensing

1995 ◽  
Vol 149 ◽  
pp. 338-339
Author(s):  
K. Døhlen ◽  
A. Cañas
Keyword(s):  
Remote Sensing ◽  
Fourier Transform ◽  
High Resolution ◽  
Near Infrared ◽  
Michelson Interferometer ◽  
Resolving Power ◽  
Diode Array ◽  
Sensing Applications ◽  
First Results ◽  
Remote Sensing Applications

We present the first results from a portable spectrometer for the visible and very near infrared based upon the principle of heterodyned holographic Fourier transform spectroscopy (HHS) (Dohi and Suzuki 1971, Dohlen 1994). The instrument uses a Michelson interferometer where one of the mirrors is replaced with a grating. This produces a spatially located, frequency-shifted interferogram which is read out by an all-reflective relay lens and a photo-diode array and processed on a portable PC. A battery pack ensures an autonomy of about 7 hours. Instrumental assets include high optical throughput, variable resolving power, and no moving parts.We have successfully used the instrument in two different remote sensing applications: detection of vegetation reflectance and atmospheric absorption.

Adapting Raman Spectra from Laboratory Spectrometers to Portable Detection Libraries

2013 ◽  
Vol 67 (2) ◽  
pp. 149-157 ◽  
Author(s):  
James C. Weatherall ◽  
Jeffrey Barber ◽  
Carolyn S. Brauer ◽  
Timothy J. Johnson ◽  
Yin-Fong Su ◽  
...  
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
First Generation ◽  
Near Infrared ◽  
Portable Detection ◽  
Intensity Response ◽  
Excitation Laser ◽  
Raman Spectral Data ◽  
Raman Spectral ◽  
Ft Raman

Raman spectral data collected with high-resolution laboratory spectrometers are processed into a format suitable for importing as a user library on a 1064 nm DeltaNu first generation, field-deployable spectrometer prototype. The two laboratory systems used are a 1064 nm Bruker Fourier transform (FT)-Raman spectrometer and a 785 nm Kaiser dispersive spectrometer. The steps taken to adapt for device-dependent spectral resolution, wavenumber shifts between instruments, and relative intensity response are described. Effects due to the differing excitation laser wavelengths were found to be minimal, indicating—at least for the near-infrared (NIR)—that data can be ported between different systems, so long as certain measures are taken with regard to the reference and field spectra.

The near-infrared bands of NO2 observed by high-resolution Fourier-transform spectroscopy

1998 ◽  
Vol 109 (23) ◽  
pp. 10217-10221 ◽  
Author(s):  
J. Orphal ◽  
S. Dreher ◽  
S. Voigt ◽  
J. P. Burrows ◽  
R. Jost ◽  
...  
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Near Infrared ◽  
Fourier Transform Spectroscopy

scholarly journals Observations of XCO<sub>2</sub> and XCH<sub>4</sub> with ground-based high-resolution FTS at Saga, Japan and comparisons with GOSAT products

2015 ◽  
Vol 8 (8) ◽  
pp. 8257-8294 ◽  
Author(s):  
H. Ohyama ◽  
S. Kawakami ◽  
T. Tanaka ◽  
I. Morino ◽  
O. Uchino ◽  
...  
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Greenhouse Gases ◽  
Near Infrared ◽  
Infrared Region ◽  
Fourier Transform Spectrometer ◽  
Solar Absorption ◽  
Average Growth ◽  
Dry Air ◽  
Increasing Trends

Abstract. Solar absorption spectra in the near-infrared region have been continuously acquired with a ground-based (g-b) high-resolution Fourier transform spectrometer (FTS) at Saga, Japan since July 2011. Column-averaged dry-air mole fractions of greenhouse gases were retrieved from the measured spectra for the period from July 2011 to December 2014. Aircraft measurements of CO2 and CH4 for calibrating the g-b FTS data were performed in January 2012 and 2013, and it is found that the g-b FTS and aircraft data agree to within ±0.2 %. The column-averaged dry-air mole fractions of CO2 and CH4 (XCO2 and XCH4) show increasing trends, with average growth rates of 2.3 ppm yr−1 and 9.5 ppb yr−1, respectively, during the ~ 3.5 yr of observation. We compared the g-b FTS XCO2 and XCH4 data with those derived from backscattered solar spectra in the short-wavelength infrared region measured with Thermal And Near-infrared Sensor for carbon Observation-Fourier Transform Spectrometer (TANSO-FTS) onboard the Greenhouse gases Observing SATellite (GOSAT). Average differences between TANSO-FTS and g-b FTS data (TANSO-FTS minus g-b FTS) are 0.40 ± 2.51 ppm and −7.6 ± 13.7 ppb for XCO2 and XCH4, respectively. Using aerosol information measured with a sky radiometer at Saga, we found that the differences between the TANSO-FTS and g-b FTS data are moderately negatively correlated with aerosol optical thickness and do not depend explicitly on aerosol size. In addition, from aerosol profiles measured with lidar located right by the g-b FTS, we were able to show that cirrus clouds and tropospheric aerosols accumulated in the lower layers of the atmosphere tend to overestimate or underestimate the TANSO-FTS data.

The c3Π – b3Σ+ transition of CO near 8245 cm−1

1987 ◽  
Vol 65 (9) ◽  
pp. 1171-1177 ◽  
Author(s):  
I. Dabrowski ◽  
M. Vervloet ◽  
D.-C. Wang
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Near Infrared ◽  
Electronic States ◽  
Direct Determination ◽  
Fourier Transform Spectroscopy ◽  
Rotational Constants

A transition between two high-lying electronic states of CO, c3Π – b3Σ+, has been observed by high resolution Fourier transform spectroscopy, in the near infrared, around 8245 cm−1. The triplet splittings of both c3Π and b3Σ+ have clearly been observed. The value A = 1.504(12) cm−1 has been determined for c3Π and confirms the previous direct determination of Klopotek and Vidal (J. Opt. Soc. Am. B, 2, 869 (1985)). Because these states were found to be heavily perturbed, only the analysis and effective rotational constants are reported.

Sign in / Sign up

Export Citation Format

Share Document