Method for estimating the transverse component of the velocity of the air in a doppler LiDAR measurement

摘要

A method for estimating the transverse component Vtrans of the velocity of the air comprises the following steps: emitting a focused laser beam; acquiring an electrical signal resulting from the transit of a particle across the beam at a point of transit; analyzing the signal so as to obtain a spectrogram revealing an elongate mark representative of the transit; estimating the duration of traversal of the laser beam by the particle and the slope of the mark; deducing from the duration and from the slope the distance between the point of traversal of the beam and the focusing point; determining the radius of the beam at the point of transit; deducing the transverse component from the radius and from the duration.

主权项

1. A method for estimating a transverse component Vtrans of a velocity of air comprising the following steps:
emitting a focused laser beam; acquiring an electrical signal s(t) resulting from a transit of a particle across the focused laser beam at a point of transit; analysing the electrical signal s(t) so as to obtain a spectrogram revealing an elongate mark representative of the said transit; estimating a duration D of traversal of the focused laser beam by the particle and a slope P of the elongate mark; deducing from the duration D and from the slope P the distance z0 between a point of traversal of the focused laser beam and a focusing point; determining a radius ω(z0) of the focused laser beam at a point of transit; and deducing the transverse component Vtrans of the velocity of air from the radius ω(z0) and from the duration D.