Tracking particle near a flat surface in digital video microscopy

Digital video microscopy (DVM) is an important tool to obtain quantitative information about underlying physics in colloidal systems. DVM, however, has the overlap problem caused by particle's diffraction pattern when the detected particles are close to contact. This overlapping problem limits the tracking methods in determining accurate particle position that reflects all interactions exerting to particles or objects in colloidal studies. The problem occurs not only between two spherical particles close to each other but also when a spherical particle is close to a rod shaped particle which have a flat surface. In this study, the simulation results on the tracking spherical particle placed near the flat surface of a rod particle in 2D digital video microscopy are reported. This work shows that the overlap problem can be resolved by using a fraction of the intensity distribution of a spherical particle which is close to a flat surface.