Velocity measuring system

摘要

A laser Doppler velocimeter uses self-mixing amplification of backreflections from scatterers below the surface of a flow. A time domain signal is divided into segments that are roughly equal to a transit time of particles through a focus of a laser beam. The segments are connected to a frequency domain through the use of an FFT algorithm to produce frequency domain data segments. Signal-to-noise ratio is enhanced through signal processing techniques using the segments to produce a final enhanced signal spectrum.

主权项

1. A method of estimating volumetric flow executable by a laser Doppler velocimeter, comprising the steps of:
directing a laser beam of the laser Doppler velocimeter to measure velocity at several points in the volumetric flow; estimating the volumetric flow using volumetric measurements at the several points; and eliminating signals from surface reflections, the eliminating signals from surface reflections includes the step of eliminating signals that are more intense and have sharper velocity profiles than signals from scattering in a bulk of a flowing stream.