Vertical refraction of light in the atmospheric surface layer: traditional problems of determining refraction and new technical achievements

Almost all the methods of determining refraction are based on the theory created by Newton. Studies performed by Newton, Euler, Oriani, Bernoulli, et al. involved the determination of the geometrical path of a light ray. However, the refraction of light propagating in the atmospheric surface layer cannot be calculated reliably because of numerous conditions determining the propagation of light in the layer. Modern methods for determining the refraction of light providing optical measurements with an instrumental accuracy of the devices used are analyzed.