Holographic particle image velocimetry apparatus and methods
US6496262B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 9, 1999 |
| Grant date | Dec 17, 2002 |
| Priority date | — |
| Expiry date | Jul 9, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2226/11
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The proposed holographic particle image velocimetry (HPIV) system employs holograms of two time-separated particle fields, illuminated by separate reference beams on a single recording medium. 90-degree scattering is utilized for the object wave, in order to improve Numerical Aperture and resolve the third dimension of the hologram. The proposed HPIV system then uses substantially the same optical geometry for the reconstruction process. A CCD camera is utilized to extract particle subimages, thin slice by thin slice, and a centroid-finding algorithm is applied to extract centroid locations for each volume. The concise cross correlation (CCC) algorithm for extracting velocity vector fields from the centroid data is an important enabling feature of the proposed system. Correlations are calculated between subsets of centroids representing the images or cubes, and velocity vectors are computed from the individual correlations. Higher spatial resolution can also be obtained by pairing particle centroids individually.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.