3D particle location from perspective shifted plenoptic images*

The application of plenoptic imaging to 3D analysis of particle field diagnostics is an emerging area of diagnostic development. A plenoptic camera uses a microlens array to collect the angular and spatial information of the incoming light rays, which can be manipulated in post processing to provide a 3D representation of a scene from a single snapshot. This work develops and tests an algorithm to determine 3D position by exploiting the perspective-shift capabilities of the plenoptic camera for measurement of explosively generated fragments. The algorithm is validated using a data set previously examined in a refocusing based study of a static particle field. Application to fluid dynamics measurements is demonstrated in examination of experimental data sets. The secondary droplet field created by the impact of a drop of water on a thin film of water and the fragment field of a lab scale detonator are measured to provide examples of particle size and shape variation.