Subpixel centroid position error analysis in particle tracking velocimetry induced by the CCD pixel binning

Particle tracking velocimetry (PTV) is a non-invasive, full field optical measuring technique that has become one of the dominant tools for obtaining velocity information in fluid motion. In PTV experiments, the fluid of interest is seeded with fluorescent tracer particles, where measurement of individual particle displacements, recorded by means of digital camera at two instances of time, is further used to ascertain overall flow motion. Upper limit of a flow speed a PTV system can measure is bound by the frame rate of a camera used, and the system's accuracy is limited by the accuracy of the particle centroid estimation.