Laser radar device for detecting atmospheric temperature based on vibration-rotation Raman spectrum

Abstract

The invention discloses a laser radar device for detecting the atmospheric temperature based on a vibration-rotation Raman spectrum. After laser is emitted from a laser device, the light beam can be amplified and the diffusion angle can be compressed by using a beam expander, and finally the light beam is emitted to the atmosphere through a pointing mirror; atmospheric back scattering light is collected by using a telescope, subsequently passes through an aperture diaphragm, and is finally led into a subsequent optical system through an optical fiber; the outgoing light of the optical fiber is converted into collimated parallel light by using a collimating lens, and is subsequently divided into two paths of signals by using a beam splitter, one path of the signals passes through a low-order signal light filtering piece, and the other path of the signals passes through a high-order signal light filtering piece; the two paths of the signal light is converted into electric signals through a photomultiplier I and a photomultiplier II, and is subsequently acquired and stored by using an acquirer. The strength of a vibration-rotation Raman spectral line is related to the atmospheric temperature, and different from a pure rotation Raman spectral line which is in an interval of 1-3nm from an elastic scattered ray, a vibration Raman spectral line is in an interval of 70nm from the elastic scattered ray, so that interference of an elastic scattering signal can be effectively avoided by adopting the vibration Raman spectral line.

Description

technical field [0001] The invention relates to the technical field of laser radar, in particular to a laser radar device for detecting atmospheric temperature based on vibrational dynamic Raman spectrum. Background technique [0002] Atmospheric temperature is an important meteorological parameter in atmospheric physics, weather forecast and atmospheric environment research. At present, the more commonly used methods are balloon sounding, satellite inversion and lidar detection. The advantages of lidar in detection accuracy and spatial resolution, as well as the continuous measurement and directional measurement, have attracted more and more attention from scientific and technical personnel. The detection of tropospheric temperature by pure rotational Raman lidar has the following weak factors: [0003] 1) In the boundary layer, aerosol layer, and cloud layer with relatively large aerosol content, the pure rotational Raman signal is interfered by the elastic scattering si...

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Problems solved by technology

[0003] 1) In the boundary layer, aerosol layer, and cloud layer with relatively large aerosol content, the pure rotational Raman signal is interfered by the elastic scattering signal of the aerosol, which makes a large difference when detecting the atmospheric temperature of the boundary layer, aerosol layer, and cloud layer. Measurement error;

[0004] 2) The high and low order Raman signals received by the pure rotation Raman lidar include the Raman signals of nitrogen and oxygen, and the temperature response functions of the Raman lines of nitrogen and oxygen are different, which makes the temperature response function of the Raman signal complicated , which brings difficulties and errors to the inversion of atmospheric temperature

[0005] 3) The intensity difference between the high-order and low-order pure rotational Raman spectral lines is large, resulting in a large difference between the two signals, which is easy to cause detection errors

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