Feasibility and accuracy assessment of light field (plenoptic) PIV flow-measurement technique

A light field camera can enable measurement of all the three velocity components of a flow field inside a three-dimensional volume when implemented in a PIV measurement. Due to the usage of only one camera, the measurement procedure gets greatly simplified, as well as measurement of the flows with limited visual access also becomes possible. Due to these advantages, light field cameras and their usage in PIV measurements are actively studied. The overall procedure of obtaining an instantaneous flow field consists of imaging a seeded flow at two closely separated time instants, reconstructing the two volumetric distributions of the particles using algorithms such as MART, followed by obtaining the flow velocity through cross-correlations. In this study, we examined effects of various configuration parameters of a light field camera on the in-plane and the depth resolutions, obtained near-optimal parameters in a given case, and then used it to simulate a PIV measurement scenario in order to assess the reconstruction accuracy.