Preliminary Development of a 3-D, 3-C PIV Technique using Light Field Imaging

A novel 3-D, 3-C PIV technique is described, based on volume illumination and a plenoptic camera to measure a velocity eld. The technique is based on plenoptic photography, which uses a dense microlens array mounted near a camera sensor to sample the spatial and angular distribution of light entering the camera. This combination of spatial and angular information is termed the light eld, and is measured in this work with a plenoptic camera. Computational algorithms are then used to reconstruct a volumetric intensity eld after the image is taken. This paper provides an introduction to the concepts of light eld photography and describes the algorithms used to render the intensity eld. The algorithms are tested using simulated data to evaluate their reconstruction accuracy and their eectiveness with correlation algorithms. Additionally, the construction of a prototype camera based on a 16-megapixel sensor is described. This work demonstrates the ability to make 3-D, 3-C PIV measurements using simulated data of uniform and vortex ow, and provides the basis for further development using experimental data and more advanced reconstruction algorithms.