A research team led by Prof. GAO Xiaoming from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences has developed a near-infrared dual-channel oxygen-corrected laser heterodyne radiometer (LHR) in the ground-based solar occultation mode, which was used to measure the vertical profile of the wind field in the troposphere and lower stratosphere.

The results were published in Optics Express.

LHR has a high spectral resolution that can effectively detect small Doppler frequency shifts caused by the wind field. Combined with the atmospheric transmission spectrum, LHR can obtain vertical profiles of horizontal winds and atmospheric column concentrations along the line of sight through spectral inversion.

In this study, the researchers designed a near-infrared laser heterodyne spectrometer based on oxygen correction, and measured the atmospheric O₂ and CO₂ transmission spectra.

Using the constrained Nelder-Mead simplex method based on the atmospheric O₂ transmission spectrum, they corrected the atmospheric temperature and pressure distribution, and combined the optimal estimation algorithm to invert the vertical profile of the atmospheric wind field with an accuracy of about ±2.5 m/s.

The results show that the oxygen-corrected LHR, as a portable and miniaturized measuring instrument, has broad application potential in wind field detection.

This study was funded by the National Natural Science Foundation of China, the National Key R&D Program, and the Director's Special Pre-Research Fund, among others.

Schematic diagram of near-infrared laser heterodyne radiometer. (Image by LI Jun)

(a). the measured atmospheric transmission spectrum; (b). the prior wind profile (blue curve) and the inverted wind profile (red dotted line). (Image by LI Jun)