Recent Development of Volumetric PIV with a Plenoptic Camera

Abstract

The recent development of a volumetric PIV system utilizing the unique light-field capturing capabilities of a plenoptic camera is described. The fundamental concept of a plenoptic camera, including a distinction between plenoptic 1.0 and plenoptic 2.0 is given, along with an illustration of the ability to computationally refocus an image after it has been acquired. A synthetic image generator for plenoptic cameras was developed and used to simulate plenoptic imaging of the motion of 3D particle fields. For volumetric reconstruction, the MART algorithm was adapted for use with the plenoptic camera through a reformulation of the weighting matrix that is consistent with the optical properties of the plenoptic camera. A prototype camera was designed and constructed based on the modification of a 16 MP PIV camera such that a microlens array can be mounted near the image sensor. This camera was used to show the proof-of-concept of the camera’s ability to measure a 3D velocity field through experiments performed in a subsonic turbulent boundary layer and a supersonic jet. In both cases, the feasibility of plenoptic PIV was demonstrated with noted strengths being the simple set-up and operation of the system in addition to the ability to make 3D measurements over relatively large volumes