Scientists study individual tiny objects such as plankton and detritus particles using flow cytometry and in situ camera systems. Flow cytometers measure sizes and take photographs of individual particles flowing through a tube system; one such instrument is the Imaging FlowCytoBot (IFCB). In situ camera systems are deployed over the side of a research vessel, alone or attached to other equipment, and they capture photographs of the water itself to image the particles present in the water; one such instrument is the Underwater Vision Profiler (UVP). Other imaging technologies used in the ocean include holography and particle imaging velocimetry (PIV), which uses 3D video footage to track the movement of underwater particles.