Normalinių aukščių nustatymo tikslumo analizė

Abstract

Normal height determination accuracy is dependent on real physical process of measuring and calculating models used or on the accuracy in model parameters. In the article the influence of the real and normal gravity for determination of normal heights is shown. The theoretical formulas for calculating standard deviations in estimating normal heights are proposed. International Association for Geodesy and Geophysics for calculating the values of normal gravity in 1980 recommended to use the model proposed by H. Moritz [2]. It was shown by theoretical and practical works that the values of normal gravity according to the given model can be determined only with a limited accuracy approximately in 1,4 mgal. Thus, by estimating final accuracy it is necessary to take into account the influence of gravity errors. It is also analysed the accuracy of normal height corrections caused by the effect of the Sun and Moon. Besides, there was shown that the motion parameters of the Sun and Moon, such as the zenith distance and azimuth may be determined with an accuracy of 3°. Then the effect of the parameter errors should be about 2% of the levelling errors, what is a negligible value.