Research on flow field measurement technology based on optical field imaging

In order to measure the underwater flow field, a set of light field imaging system based on microlens array is designed and built based on the principle of light field imaging. The system can continuously sample the flow field of tracer particles, and the obtained images can expand the depth of field through digital refocusing calculation, restore the imaging situation of each focal plane, and extract the focal particles. At the same time, particle image velocimetry is used to calculate the detected flow field, and the flow field results are obtained. The system combines light field technology with microscopic imaging technology to track small particles and expand the depth of field. Its light path and structure design are simple and reliable, and can be used in the development of underwater in-situ detection instruments.