A Scintillometer's a scientific device used to measure small fluctuations of the refractive index of air caused by variations in temperature, humidity, and pressure. It consists of an optical or radio wave transmitter and a receiver at both ends of an atmospheric propagation path. The receiver detects and evaluates the intensity fluctuations of the transmitted signal, called scintillation. The magnitude of the refractive index fluctuations's usually measured in terms of Cn^2, the structure const… (More on Scintillometer)