Impulse radar for measuring wind speeds - receives HF EM waves reflected from inhomogeneities in atmosphere to determine drift velocity

摘要

The transmitting antenna, emits a series of high frequencies oscillation impules (12), directed vertically above it, which are reflected from the turbulence (14) of the atmosphere. The reflected impulses are collected by two receiving antennae (16,18) and fed to high frequency receivers (20,22). The receiving antennae (16,18) are receptive to different parts of the turbulence (14a,14b) and after a certain period, one part of this turbulence (14a) reaches the position previously occupied by a former part (14b). If the configuration of the turbulence (14) does not change considerably, the receiving antennae (16,18) are receptive to the same turbulence profile only in a time interval which corresponds to the speed of the turbulence from one field of view to the other, this time difference being provided by a correlator (24). The height window (H) in which the displacement speed of the turbulence (14) is measured, is determined by the travel time range of the high frequency impulses. By sampling a number of bordering height fields, a height profile of the drift speed is built up, and can be displayed visually.