The TSI Global Sizing Velocimeter (GSV) system measures droplet size and velocity simultaneously in sprays and other multiphase flows. The measurement plane is illuminated with a light sheet from a double-pulsed Nd:YAG laser, and a single TSI PowerView Plus camera. This single camera, equipped with a standard 105mm camera lens and unique GSV aperture, captures frame-straddled images of the droplets. An interferometric technique measures size with highly accurate results. Velocity is extracted from the frame-straddled image pair using a unique and powerful tracking algorithm.