Jd. Trolinger et al., DEVELOPMENT AND APPLICATION OF HOLOGRAPHIC PARTICLE IMAGE VELOCIMETRYTECHNIQUES FOR MICROGRAVITY APPLICATIONS, Measurement science & technology, 8(12), 1997, pp. 1573-1583
Holographic particle image velocimetry instruments at both velocity ex
tremes have been developed and applied. Except for the type of laser r
equired, the fundamental recording and data processing methods are sim
ilar for both cases. This paper summarizes recording and reconstructio
n schemes, software for data reduction, and methods for data presentat
ion. An example application focuses on the extreme low-velocity case i
n which a three-size matrix of tracer particles was added to a solutio
n in a crystal-growth-in-space experiment to quantify and analyse micr
oconvection in a microgravity environment. Over 1000 holograms of 1000
particles were produced in a Spacelab mission, leading to the need to
process millions of images. Particle velocities ranged from 0.1 to 1
mm h(-1). Reconstructed particle images were located with a computer t
raversed microscope imaged on a CCD array, and tracked with software d
esigned to establish a reference frame in each hologram and precisely
locate the particle centres. The measurements allow determination of t
he convective field, the residual gravitational field and gravity-jitt
er.