3D Particle Positions from Computer Stereo Vision in PK-4
This work addresses a specific technical challenge in complex plasma research for scientists studying particle dynamics in microgravity, but it is incremental as it builds on prior methods by incorporating the laser sheet width.
The paper tackles the problem of accurately determining 3D particle positions in complex plasmas using stereo vision from two cameras in the PK-4 microgravity facility, by improving the transformation method to account for the laser sheet width, potentially enabling better particle tracking in the overlap region.
Complex plasmas consist of microparticles embedded in a low-temperature plasma containing ions, electrons and neutral particles. The microparticles form a dynamical system that can be used to study a multitude of effects on the level of the constituent particles. The microparticles are usually illuminated with a sheet of laser light, and the scattered light can be observed with digital cameras. Some complex plasma microgravity research facilities use two cameras with an overlapping field of view. An overlapping field of view can be used to combine the resulting images into one and trace the particles in the larger field of view. In previous work this was discussed for the images recorded by the PK-4 Laboratory on board the International Space Station. In that work the width of the laser sheet was, however, not taken into account. In this paper, we will discuss how to improve the transformation of the features into a joint coordinate system, and possibly extract information on the 3D position of particles in the overlap region.