Measurements of a fully resolved contour of the carbon dioxide absorption line in a band at λ = 1.605 μm in the atmospheric column using high-resolution heterodyne spectroradiometry

We consider the application of the heterodyne signal detection technique to measure the atmospheric transmission spectrum in the near-IR range, which makes it possible to measure for the first time the contour of a separate line of the vibrational – rotational CO₂ band on the solar observation path with a high spectral resolution of λ/δλ = 10⁸. Together with other characteristics of the instrument, this enables us to measure the carbon dioxide content in the atmospheric column with high accuracy. The experimental setup and measurement technique are described. The existing facilities for measuring the content of greenhouse gases in the atmosphere are compared, demonstrating the possibility of using the near-IR heterodyne spectroradiometry to develop a useful and competitive instrument that can be used in building new networks of ground stations to monitor greenhouse gases.