US 6,480,142 B1 · Method and apparatus for measuring velocity and turbulence of atmospheric flows

Abstract

A method and apparatus for measuring the parameters of atmospheric turbulent flows utilizes the Doppler shifted frequencies of received radar signals backscattered from sound generated aerodynamically by atmospheric turbulent flows. Doppler frequency bandwidths of the received backscattered signals are used to estimate the atmospheric flow turbulence and the mean frequency within a bandwidth is processed to estimate its radial flow velocity. Total flow velocity and the flow velocity angle with respect to the antenna boresight of the atmospheric turbulent flow may be estimated by estimating the radial flow velocity at two radial positions and processing these radial velocities. Processing of the Doppler data is initiated when the total signal power within the Doppler frequency band exceeds a predetermined power level.

Claims28

Dependent claims

A sensor of atmospheric turbulent flows having a radar transmitter and a radar receiver positioned and arranged to receive radar signal reflections of the transmitted radar signals from atmospheric refractive index variations induced by acoustic waves that are aerodynamically generated by the atmospheric turbulent flows, thereby providing received radar signals, comprising:

a signal processor coupled to said radar receiver wherein said received radar signals are processed to select at least one band of signals at Doppler shifted frequencies, thereby providing at least one Doppler frequency band, to estimate spectral width and mean frequency of said at least one Doppler frequency band, and to estimate signal power in said at least one Doppler frequency band;
and
a spectrum processor coupled to said signal processor for processing said spectral width and mean Doppler frequency of said at least one Doppler frequency band to provide an estimate of atmospheric flow turbulence and radial flow velocity.

A method for determining air flow turbulence and flow velocity of atmospheric turbulent flows from radar signals reflected from atmospheric refractive index variations induced by acoustic waves that are aerodynamically generated by the atmospheric turbulent flows comprising the steps of:

providing an antenna, having a boresight for transmitting radar signals and receiving said reflected radar signals;
processing said reflected radar signals received at said antenna to select at least one band of signals at Doppler shifted frequencies, thereby providing at least one Doppler shifted frequency band;
deriving estimates of spectral width, mean frequency, and signal power of said at least one Doppler shifted frequency band;
and
utilizing said spectral width, said mean frequency, and said signal power to derive estimates of said air flow turbulence and radial air flow velocity.

2 more elements

Dependencies are inferred from the claim text.

Method and apparatus for measuring velocity and turbulence of atmospheric flows

Life of this patent

Method and apparatus for measuring velocity and turbulence of atmospheric flows

Life of this patent

Abstract

Claims28