METHOD OF VELOCITY VECTOR LASER MEASUREMENT Russian patent published in 1998 - IPC

FIELD: experimental hydrodynamics and aerodynamics. SUBSTANCE: laser beams which form probing fields with preset sensitivity vectors are directed to area under examination, light beams scattered in probing field are separated, and their photoelectric conversion is performed. Electric signals with frequencies corresponding to projections of velocity vector on preset sensitivity vectors are selected. Frequencies of selected electric signals are measured and transformed to values of respective components of velocity vector by means of known linear conversions determined by spatial configuration of probing field sensitivity vectors. Mutually orthogonal components of velocity vector are determined by subtraction and summing up in pairs of frequencies of electric signals corresponding to velocity vector projections on sensitivity vectors in selected pair. Moduli of these sensitivity vectors are preset to be equal. Summary or difference frequency of component of square-converted signal corresponding to heterodyne photomixing of superposition of light beams scattered in direction of bisectrix of angle between probing laser beams, is measured in differential configuration of laser beams. Summary or difference frequency of component of square- converted signal corresponding to heterodyne photomixing of light beams scattered in directions symmetrical relative to measured component of velocity vector and coplanar to it. EFFECT: higher measurement results. 3 cl, 3 dwg