An Error Correction Method for Incoherent Doppler LiDAR Wind Velocity

Abstract

The invention discloses an error correction method of the wind speed by an incoherent Doppler laser radar. The error correction method comprises the following steps of measuring backward scattered light of the atmosphere and obtaining a zero-wind-speed ratio r0 when radial wind speed VLOS measured is equal to 0, a wind-speed ratio RW,+ when the radial wind speed VLOS measured is equal to -deltavlambda / 2, a wind-speed ratio RW,- when the radial wind speed VLOS measured is equal to deltav'lambda / 2; solving dRW / dv by a least square method, obtaining sensitivity S, adjusting the frequency of transmitting laser to reference frequency v0, measuring the wind-speed ratios in the four directions, namely east, west, south and north, respectively dividing the sensitivity S to obtain measured radial wind speeds in all the directions, and synthesizing to obtain measured wind speed VM; calculating an error table; and finding corresponding errors dV according to the sensitivity S and the measured radial wind speeds in all the directions, wherein the actual radial wind speed VLOS is equal to the difference of the measured radial wind speed VM and the error dV. The error correction method disclosed by the invention has the advantages that a wind-speed error about 3m / s introduced by atmospheric temperature and atmospheric molecule scattering models in theoretical calculation can be eliminated to the greatest extent, the wind-speed measurement accuracy of the incoherent Doppler laser radar can be improved, the measurement time is short and the convenient and fast effects are achieved.

Description

technical field [0001] The invention belongs to the technical field of laser radar, and in particular relates to an error nonlinear correction method based on the sensitivity and precise direct measurement of the wind speed obtained in the incoherent wind measuring laser radar of the iodine molecular filter-the error correction method of the wind speed of the incoherent Doppler laser radar. Background technique [0002] When Doppler lidar is used to measure wind speed, according to the Doppler principle, the overall movement of atmospheric molecules or aerosol particles that characterize the wind speed will shift the frequency of backscattered laser light, that is, the Doppler frequency shift. The radial wind speed is V LOS , the Doppler frequency shift produced by atmospheric backscattered light is Δν=–2V LOS / λ (where λ is the laser wavelength). The frequency detection devices of incoherent Doppler lidar (such as iodine molecular absorption filter) have a steep absorptio...

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Problems solved by technology

[0009] In short, the above methods are not direct measurement methods, nor do they take into account the deviation of atmospheric temperature and the error of the atmospheric molecular scattering model itself.

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