Atmospheric Measurements by Ultra-Light SpEctrometer (AMULSE) Dedicated to Vertical Profile in Situ Measurements of Carbon Dioxide (CO₂) Under Weather Balloons: Instrumental Development and Field Application.

The concentration of greenhouse gases in the atmosphere plays an important role in the radiative effects in the Earth's climate system. Therefore, it is crucial to increase the number of atmospheric observations in order to quantify the natural sinks and emission sources. We report in this paper the development of a new compact lightweight spectrometer (1.

Wavelet denoising for infrared laser spectroscopy and gas detection.

After a brief introduction to wavelet theory, this paper discusses the critical parameters to be considered in wavelet denoising for infrared laser spectroscopy. In particular, it is shown that measurement dispersion as well as sensibility can be dramatically improved when using wavelet denoising for gas detection by infrared laser absorption spectroscopy.

Self-induced pressure shift and temperature dependence measurements of CO2 at 2.05μm with a tunable diode laser spectrometer.

By using a high resolution tunable diode laser absorption spectrometer combined with a cryogenically cooled optical multi-pass cell, we have measured the self-induced pressure shift coefficients for 8 transitions in the R branch of the (20(0)1)(III)←(00(0)0)(I) band of carbon dioxide around 2.05μm. This spectral region is of particular interest for the monitoring of atmospheric CO(2) with Differential Absorption Lidars (DiAL).

Diode laser spectroscopy of two acetylene isotopologues ((12)C2H2, (13)C(12)CH2) in the 1.533 microm region for the PHOBOS-Grunt space mission.

Several line intensities of the nu(1) + nu(3)(Sigma(u)(+)) - 0(Sigma(g)(+)) bands of (12)C(2)H(2) and (13)C(12)CH(2) at 1.533 microm have been revised at room temperature. These molecular transitions were selected to measure acetylene within the framework of the Martian space mission PHOBOS-Grunt.

Laser diode absorption spectroscopy for accurate CO(2) line parameters at 2 microm: consequences for space-based DIAL measurements and potential biases.

Space-based active sensing of CO(2) concentration is a very promising technique for the derivation of CO(2) surface fluxes. There is a need for accurate spectroscopic parameters to enable accurate space-based measurements to address global climatic issues. New spectroscopic measurements using laser diode absorption spectroscopy are presented for the preselected R30 CO(2) absorption line ((20(0)1)(III)<--(000) band) and four others.

Inter-comparison of 2 microm Heterodyne Differential Absorption Lidar, Laser Diode Spectrometer, LICOR NDIR analyzer and flasks measurements of near-ground atmospheric CO2 mixing ratio.

Remote sensing and in situ instruments are presented and compared in the same location for accurate CO(2) mixing ratio measurements in the atmosphere: (1) a 2.064 microm Heterodyne DIfferential Absorption Lidar (HDIAL), (2) a field deployable infrared Laser Diode Spectrometer (LDS) using new commercial diode laser technology at 2.68 microm, (3) LICOR NDIR analyzer and (4) flasks.

Development of a spectrometer using a continuous wave distributed feedback quantum cascade laser operating at room temperature for the simultaneous analysis of N2O and CH4 in the Earth's atmosphere.

We report on the development and performance of a gas sensor based on a distributed feedback quantum cascade laser operating in continuous wave at room temperature for simultaneous measurement of nitrous oxide (N(2)O) and methane (CH(4)) concentrations at ground level. The concentrations of the gases are determined by a long path infrared diode laser absorption spectroscopy. The long-term stability of the instrument is evaluated using the Allan variance technique.

New improvements in methane detection using a Helmholtz resonant photoacoustic laser sensor: a comparison between near-IR diode lasers and mid-IR quantum cascade lasers.

Atmospheric methane was detected by combining a photoacoustic (PA) sensor with several lasers emitting in both the near- and mid-infrared spectral ranges to check the achievable detection limits. The PA spectrometer is based on differential Helmholtz resonance. Near-infrared telecommunication-type laser diodes of increasing power, from Sensors Unlimited Inc.

Open multipass absorption cell for in situ monitoring of stratospheric trace gas with telecommunication laser diodes.

A two-mirror multipass absorption cell that is operated open to the atmosphere from a stratospheric balloon to monitor in situ methane (in the 1.65-microm region) and water vapor (in the 1.39-microm region) with telecommunication laser diodes is described.