Multi-Camera Plenoptic Particle Image Velocimetry

Abstract

Recently, plenoptic or lightfield cameras have been proposed for performing single camera three-dimensional fluid velocity field measurement due to their unique nature of recording both the spatial variation and the propagation direction of the incoming light. The combination of both the spatial and angular information of the light yields the lightfield function, which in turn can be used to create three-dimensional reconstructions. Unfortunately single camera plenoptic PIV measurements suffer from the same low angular resolution problems as do the single camera defocusing PIV and holographic PIV techniques. To increase the quality of the volumetric reconstructions a multiplicative, multiple plenoptic camera reconstruction algorithm is derived and it is shown in lightray simulations that using multiple plenoptic cameras can produce three-dimensional intensity fields with much higher fidelity to the true field than the reconstructions produced by a single camera. Moreover, the intensity fields produced using multiple plenoptic cameras have comparable or higher fidelity than those produced using tomographic PIV techniques with the same number and orientation of cameras.