Photogrammetric set-up for the analysis of particle motion in aerosol under microgravity conditions

An optical set-up to investigate the motion of aerosol particles under micr ogravity conditions has been designed and manufactured. It provides accurat e measurement of 3D coordinates of up to 1000 particles, discrimination bet ween particles of different nature and estimation of the angular velocity o f small aerosol crystals. A photogrammetric technique is applied to track i ndependently moving particles, using the acquisition and processing of ster eoscopic image sequences. The optical scheme of the set-up is based on a un ique objective that collects the light coming from different directions fro m the back- and front-illuminated aerosol, and transfers it to four differe nt cameras. Driving parameters for the optical head design and image qualit y are discussed. The set-up performance was verified on optical test object s, aerosol simulators and also real aerosol under microgravity conditions d uring parabolic flight. The set-up has been designed for use in the JET exp eriment on board the Maser 8 sounding rocket. The experiment aims at the fi rst direct observation of the chemojet motion of free-flying small growing crystals. Investigation of chemojet motion along with elaboration of the im age analysis technique is focused on the development of highly sensitive, r eal-time, non-perturbative analysis of the reactions on the surface of aero sol particles.