Distributed processing for cinematic holographic particle image velocimetry

Recently the GEMINI Holographic Particle Image Velocimetry (HPIV) system developed in the Laser Flow Diagnostics (LFD) lab at Kansas State University has been successfully applied in volumetric 3D flow velocity measurement. Due to the 3D nature of this application, very large computation and communication requirements are imposed. An innovation algorithm, the Concise Cross Correlation (CCC), is employed in the system to extract velocity field from the hologram of the test flows. With CCC we achieved a compression ratio of 10⁴ and a processing speed 1000 times faster than with traditional 3D FFT-based correlation. To further accelerate the processing speed for fully time- and space-resolved measurement, parallel processing is necessary. We present our design for a distributed system supporting this previously unparallelized application, and comment on our experiences implementing a master-slave distributed version of CCC utilizing MPI. Brief experimental results on Gigabit Ethernet and multiprocessor Pentium Xeon systems are given