Simulation of wind field detection by laser heterodyne spectrometer

Abstract

The middle- and upper- atmosphere wind field are important parameters that characterize the middle- and upper-atmosphere environment, respectively. The detection of the middle- and the upper-atmosphere wind field are of great significance in the civil field and military field. Laser heterodyne spectroscopy technology is a passive remote sensing detection technology with high spectral resolution and sensitivity, and has developed rapidly in recent years. The laser heterodyne spectrometer that takes laser heterodyne spectroscopy technology as its core, is developed due to its small size, light weight and stable structure. The verification of the ground-based wind field detection performance of the laser heterodyne spectrometer is a key part of its application to satellites. In this paper, a wind speed simulation device is built in a laboratory environment to achieve a wind speed change from 0 m/s to 25 m/s in a wind field. A laser heterodyne spectrometer with a spectral resolution of 0.003 cm<sup>–1</sup> is used to measure the CH<sub>4</sub> absorption spectrum without and with a wind field for different wind speeds, the resolution of measuring wind speed is 3 m/s. For relative and absolute calibration of the distributed feedback laser (DL) frequency, an interference fiber with a free dispersion range <i>D</i><sup>*</sup> = 0.01167 cm<sup>–1</sup>, a wavemeter and a reference cell is used. The experimental results effectively verify the wind measurement performance of the laser heterodyne spectrometer and prove the possibility of using the laser heterodyne spectrometer to measure the atmospheric wind field.