Coherent wind measurement laser radar based on single-photon detection

Abstract

The invention discloses a coherent wind measurement laser radar based on single-photon detection. According to the technical scheme, a coherent detection mode is adopted to transform the detection frequency from THz to MHz through atmospheric echo signal and local oscillator light beat frequency; digital sampling is carried out on the radio-frequency signal through a single photon detector, thereby simplifying signal processing; and information of an atmospheric wind field is extracted by carrying out Fourier transform on the digital signal. According to the coherent wind measurement laser radar based on single-photon detection, compared with a direct detection mode, the coherent detection mode simplifies light path and improves system stability; and besides, through single-photon detection, difficulty in signal transmission, storage and processing is reduced and real-time processing is realized.

Description

technical field [0001] The invention relates to the technical field of wind-measuring lidar, and more specifically, relates to a coherent wind-measuring lidar based on single-photon detection. Background technique [0002] Atmospheric wind field remote sensing has extensive social benefits and important military applications. Social efficiency includes: numerical weather forecasting, air pollution detection and forecasting, meteorology and climatology research, aviation, navigation, highway visibility detection, improving wind power generation efficiency, Agricultural applications (rainfall, frost, high temperature warning); military applications include: aircraft carrier operations, adjacent space environment protection, air combat planning and command, early warning of release of biological and chemical weapons, precision airdrops, aerial refueling. Due to its high precision, high temporal and spatial resolution and long detection distance, wind lidar is an effective means...

AI Technical Summary

Problems solved by technology

Direct detection converts Doppler frequency changes into energy changes by using a frequency discriminator, such as a Fabry-Perot interferometer. The difficulty is that the frequency discriminator drifts under the influence of ambient temperature, humidity and pressure , it is necessary to lock the center frequency of the laser on the steep edge of the discriminator in real time, and the optical path is complex

The coherent detection changes the detection frequency from the THz level to the MHz level by beating the atmospheric echo signal and the local oscillator signal, and then samples the digital signal through a high-speed analog acquisition card, and extracts the frequency shift information through Fourier transform , the difficulty is that high-speed analog acquisition card sampling brings challenges to real-time data transmission, storage and processing

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