Pulse coherent wind lidar system

Abstract

The invention relates to the technical field of laser radars, and discloses a pulse coherent wind measurement laser radar system, which comprises a light source module used for emitting local oscillator continuous laser; the light splitting module is used for splitting light, a first part of light enters the frequency shift module, and a second part of light enters the frequency mixing module; the frequency shift module is used for performing frequency shift, modulation and amplification processing on the first part of light to obtain pulse laser; the multimode circulator is used for transmitting the pulse laser into the telescope, receiving an echo signal returned by the telescope and transmitting the echo signal into the optical amplifier; the optical amplifier is used for amplifying the echo signal; the frequency mixing module is used for carrying out coupling frequency mixing processing on the amplified echo signal and the second part of light; and the detection module is used for performing signal conversion and data processing on the mixed optical signal. The multi-mode circulator is used to enlarge the optical receiving field angle, the optical receiving efficiency is improved, the optical amplifier is used to realize the amplification of the whole signal intensity, and the signal-to-noise ratio and the detection distance of the system are improved.

Description

technical field [0001] The invention relates to the technical field of laser radar, in particular to a pulse coherent wind measurement laser radar system. Background technique [0002] The atmospheric wind field is the main driving force for the circulation of moisture, aerosols and other substances in the atmosphere, and has very important research value in the research of weather forecast, earth environment and dynamic meteorology. Coherent wind measurement is to measure the atmospheric wind field by coherently mixing the atmospheric laser echo signal with the local oscillator laser. The coherent Doppler wind lidar can measure the radial wind speed by detecting the Doppler frequency shift of the laser echo signal. [0003] At present, coherent Doppler wind lidar systems usually use a single-mode fiber circulator to receive and receive light signals, so as to realize an integrated optical structure for transceivers. However, the core diameter of a single-mode fiber is gen...

AI Technical Summary

Problems solved by technology

However, the core diameter of a single-mode fiber is generally about 9um, and the numerical aperture NA is 0.11, resulting in a small receiving field of view, low optical receiving efficiency, and low coupling efficiency with the telescope. The highest theoretical coupling efficiency is 81.45%. The efficiency in the actual process will be lower, which will reduce the signal-to-noise ratio and measurement distance of the system

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