Ozone space-time differential absorption laser radar system based on CO2 single Raman tube and detection method

Abstract

The invention discloses an ozone space-time differential absorption laser radar system based on a CO2 single Raman tube and a detection method. The system comprises a laser emission unit, an optical receiving unit and a signal acquisition and signal analysis unit. The laser emission unit adopts a CO2 single Raman tube light source system and also emits lasers of 276 nm, 287 nm and 299 nm; a Cassegram type telescope is used for receiving ultraviolet multi-wavelength back scattering light; a high-resolution grating spectrometer is used for color separation of multi-wavelength back scattering light; the optical signal from the optical receiving unit is converted into a digital signal by the signal acquisition unit and is stored in an industrial personal computer; real-time analysis is performed through the signal analysis unit, the detection blind area can be effectively reduced, the influence of aerosol interference factors is reduced, simultaneous monitoring of boundary layer ozone andfree troposphere ozone is realized, the system is especially suitable for ozone vertical profile monitoring in a heavy haze process, and realizes high-temporal-spatial-resolution and high-precision day and night measurement of the boundary layer ozone and the free troposphere ozone in different weather scenes such as the heavy haze process and clean weather.

Description

technical field [0001] The invention relates to an optical telemetry receiving device, in particular to a CO-based 2 Ozone spatiotemporal differential absorption lidar system and detection method with single Raman tube. Background technique [0002] Tropospheric ozone is an important greenhouse gas, which plays an important role in the Earth's radiation budget. In the industrial age, the radiative forcing caused by ozone reached about 0.4W m -2 . On the ground, ozone is a polluting gas with strong oxidizing properties that can damage biological tissues and seriously damage human health, vegetable and crop yield and quality. Due to the strong oxidizing properties of ozone, the lifespan of tropospheric ozone is very short, and varies greatly with altitude and region. Tropospheric ozone mainly comes from the oxidation of premise substances from natural and man-made sources, regional advective transport, and exchange between the stratosphere and the troposphere. It is of gre...

AI Technical Summary

Problems solved by technology

Researchers usually use Nd:YAG laser to pump D 2 Single Raman tube or D 2 、H 2 Dual Raman tubes generate a differential absorption light source as a light source for ozone detection, where Nd:YAG pumps D 2 There is a large Raman frequency shift in a single Raman tube, which produces pump light at 266nm, 289nm, and 316nm. The wavelength interval is large, and the aerosol-sensitive spectral factor is large. The interference effect of aerosols in the measurement of haze days cannot be ignored

while Nd:YAG pumps D 2 、H 2 The double Raman tubes produce 289nm and 299nm lasers, the wavelength interval is small, and the aerosol-sensitive spectral factor is relatively reduced by 1 / 2, but at the same time it brings three relatively large problems: (1)D 2 、H 2 The double Raman tube distributes the energy of the Nd:YAG laser, which will put forward higher requirements on the pumping energy of the pump light source Nd:YAG laser; (2)D 2 、H 2 Double Raman tubes will cause a large difference in the geometric factors of the 289nm and 316nm echo signals, which will increase the detection blind area of ​​the ozone lidar and reduce the use value of the ozone lidar data;

[0004] (3) The dual Raman tube laser emission system is relatively complex and large in size, which limits its application area scenarios

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