A system and method are provided for receiving light that has traveled from an optical source through an atmosphere along a distance. The system includes: a receiver lens system having an aperture and being arranged to receive the light from the optical source; a beam splitter; an imaging lens; an image processing component; a photodetector system; and a refractive index structure parameter component. The photodetector system outputs data associated with averaged scintillation data of the aperture. The image processing component generates a normalized covariance curve based on a first portion of the received light. The refractive index structure parameter component generates a refractive index structure parameter, Cn2, of the atmosphere along the distance based on the data associated with averaged scintillation data of the aperture and the normalized covariance curve.