Atmospheric carbon dioxide concentration detection differential absorption laser radar system

Abstract

The invention provides an atmospheric carbon dioxide concentration detection differential absorption laser radar system. The atmospheric carbon dioxide concentration detection differential absorption laser radar system comprises a laser emission subsystem, a telescope transmit-receive subsystem, a coherent detection subsystem and a signal acquisition processing and control subsystem. According to the invention, a 2 [mu]m agile single-frequency pulse laser which can be switched between an on-line wavelength and an off-line wavelength is creatively adopted as a detection light source, and On and Off seed laser time-sharing injection frequency locking is realized, so that On and Off seed laser output rapid switching is realized, and errors caused by atmospheric turbulence are restrained to the greatest extent; coherent heterodyne detection and injection frequency locking are used in cooperation, the difference value between the off light source wavelength and the on light source wavelength is stabilized, and the carbon dioxide concentration detection precision is improved. The MOPA amplification technology is adopted to realize the output of high-power laser, and the carbon dioxide concentration detection distance is increased; the volume of the laser radar is reduced by sharing a telescope, the detection precision of the laser radar is improved by adopting a coherent detection system, and the carbon dioxide concentration profile within the height range of 0-3km can be obtained with high resolution.

Description

technical field [0001] The invention relates to the technical field of measurement and testing, in particular to an atmospheric carbon dioxide concentration detection differential absorption laser radar system. Background technique [0002] Lidar has become one of the most effective means of carbon dioxide gas measurement due to its large measurement range, high temporal and spatial resolution, and real-time performance. compared to N 2 、H 2 O detection, CO 2 The scattering cross-section is small, the content in the atmosphere is small, and it is difficult to detect. Internationally, applied to CO 2 The detection lidar mainly includes differential absorption radar and Raman scattering lidar. Raman scattering radar has the advantages of no strict selection of laser wavelength and relatively simple system structure, but its detection sensitivity is low. The differential absorption principle relies on the absorption spectrum of the gas to be measured, which requires the s...

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Problems solved by technology

[0005] In order to solve the problem of measurement accuracy of carbon dioxide concentration profile, the present invention innovatively uses a 2μm agile single-frequency pulse laser that can be switched between on-line wavelength and off-line wavelength as a detection light source to realize On and Off seed laser Time-sharing injection frequency locking, so as to realize the rapid switching of On and Off seed laser output, and minimize the error caused by atmospheric turbulence; at the same time, the coherent heterodyne detection and injection frequency locking can stabilize the wavelength of the off light source and the on light source The difference between the wavelengths improves the detection accuracy of carbon dioxide concentration; the use of MOPA amplification technology can realize the output of high-power laser and increase the detection distance of carbon dioxide concentration; the volume of the laser radar is reduced by sharing the telescope, and the detection of the laser radar is solved by using the coherent detection system Accuracy problem, the carbon dioxide concentration profile within the height range of 0-3km can be obtained with high resolution

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