Abstract
Abstract This paper is concerned with the study of new turbulent method technique for the determining of vertical refraction when total stations are used. Required measurement accuracy of vertical refraction by conventional methods is extremely difficult due to rapid random changes in the angle of refraction. Geodetic observations are recommended to performing only during periods of indifferent temperature stratification, while the refraction is close to zero and practically unvaried. However, this period is extremely short and its boundaries are not defined, so the inefficiency of all known methods for determining refraction must be attention. The complete liberation of geodetic observations from the influence of turbulent and fluctuation processes in the atmosphere is possible only by directly measuring the angle of refraction at the time of observation. The creation of electronic total stations with automatic guidance to the target allows to successfully solving the problem of determining refraction by a turbulent method. The aim of this work is to study the new method for determining refraction in a turbulent atmosphere. The measurements are performed with a Trimble total station. The obtained results confirm that the accuracy for determining refraction is ~2″, which almost corresponds to the instrumental accuracy of the device used.
Highlights
The precise determination of vertical refraction by traditional methods is extremely di cult due to rapid random changes in the angle of refraction [Neyezhmakov et al, 2018; Maslich, 1969; Böhm and Schuh, 2012]
This paper is concerned with the study of new turbulent method technique for the determining of vertical refraction when total stations are used
Geodetic observations are recommended to performing only during periods of indi erent temperature strati cation, while the refraction is close to zero and practically unvaried
Summary
The precise determination of vertical refraction by traditional methods is extremely di cult due to rapid random changes in the angle of refraction [Neyezhmakov et al, 2018; Maslich, 1969; Böhm and Schuh, 2012]. The periods of stable temperature strati cation in the surface layer of the atmosphere occur when the vertical temperature gradient is close to adiabatic. This time is observed in summer about 3 hours before sunset and 3 hours after sunrise. This time is usually recommended for measuring vertical angles. Uctuations in temperature gradients occur much more slowly and the period of favorable time for measuring vertical angles increases. If the soil temperature is equal to the air temperature, the layering is stable, the signals calm down, and normal refraction corresponds to this state [Struwe, 1849]
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