Trigonometric levelling

The purpose of the study is to attempt to determine the deviation of vertical lines using trigonometric levelling and Global Navigation Satellite System (GNNS) measurements. For the last decades with the emergence of high-precision electronic theodolites and tacheometers, trigonometric levelling becomes a competitor of the geometric levelling of the II and III accuracy classes. This is primarily the definition of exceedances at distances up to 1–2 km for topographic surveying and the study of geodynamic processes in zones of the man-made load.

Aim. To investigate the possibilities of applying non-simultaneous reciprocal trigonometrical levelling over water surfaces while partially taking into account vertical refraction. Methodology. Experimental investigations of vertical refraction over water surfaces during day time on a plain and hilly terrains in summer. Non-simultaneous reciprocal observations were made over different water surfaces with the use of an automated electronic tachymeter.