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We combine a guassian plume model with dual-comb spectrometer (DCS) data to quantify both a localized leak, by measuring to a flying retroreflector, and distributed traffic carbon emissions, by differential path measurements over a city.

Mid-infrared dual-comb spectroscopy (DCS) is performed on liquid isopropanol from 3.0-3.75 μm with a 1.5-second acquisition time. This experiment is a first step towards viewing liquid-phase reactions in real time using DCS.

We demonstrate MIR-DCS across a 1-km open-air path probing the C-H stretch region around 3.2 μm. We show sensitivity to VOC’s such as acetone even in the presence of water vapor interference.

We use a dual frequency comb system to measure the city enhancement of CO2 and CH4 over Boulder, CO. We then use a simple box model to estimate the city emissions of CO2.

Dual comb spectroscopy is a promising technique for high accuracy measurement of trace gas concentrations. Here we study the impact of residual phase noise on the frequency combs on retrieved trace gas concentrations.

We demonstrate dual-comb spectroscopy over a 11.6-km long urban open air path. The system provides time-resolved, high accuracy measurements of atmospheric transmission in the 1.6 micron atmospheric window for greenhouse gas quantification.

Near-infrared frequency-comb spectroscopy is a powerful tool with which to measure absorption of CO 2 , CH 4 , H 2 O over turbulent paths such as meter scale paths in active furnaces or 11 km horizontal paths over cities. Work of the U.S. government, not subject to copyright.

Near-infrared frequency-comb spectroscopy is a powerful tool with which to measure concentrations of gasses relevant to combustion and atmospheric monitoring (CO2, CH4, H2O, HDO) over meter and kilometer scale paths.

Trace gas concentration is measured across a turbulent open-air path. Using the appropriate dual-comb configuration, phase and absorbance spectra are simultaneously obtained. Decoherence caused by turbulence is estimated and corrected for.