Geodesy, Cartography and Aerial Photography

Abstract

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. For comparing the results, the elevations between the points of observation were determined by the method of geometric levelling. Results. Average integral quantities of vertical refraction have been computed. It has been revealed that either stable or unstable stratification of the terrestrial atmospheric layer can set in over the water surfaces.