A large part of geodetic sensor systems use electromagnetic radiation to determine the measurement values (distances, directions, etc.). The geometry of the path of propagation and the velocity of the electromagnetic wave is strongly influenced by the physical state of the atmosphere. As most geodetic measurements are performed in the lower atmosphere, the study of refraction and of corresponding impact constitutes a key research field. In geodesy, the refractive index represents a common way to describe the terrestrial refraction – the literature refers to different methods for determining this value. Our study presents a method for the determination of the influence of refraction on the basis of optical measurements. The mathematical derivation is based on wellknown equations – the combination of different approaches leads to a uniform processing sequence which can easily be implemented. We present the theoretical foundations, details about the implementation and some preliminary tests.     «

A large part of geodetic sensor systems use electromagnetic radiation to determine the measurement values (distances, directions, etc.). The geometry of the path of propagation and the velocity of the electromagnetic wave is strongly influenced by the physical state of the atmosphere. As most geodetic measurements are performed in the lower atmosphere, the study of refraction and of corresponding impact constitutes a key research field. In geodesy, the refractive index represents a commo...     »