Solar Radiation and a Solution for Trigonometric Levelling Atmospheric Refraction.

Document Type : Research Studies

Author

Civil Engineering Department., Faculty of Engineering., El-Mansoura University., Mansoura., Egypt.

Abstract

Trigonometric levelling is one of the most important techniques in surveying works, however its results depends mainly on the systematic refraction error determination In order to totally or partially eluninate the influence of systematic refraction error on observations, more attention should be paid to the source of such error. Daily solar radiation is considered the main source of the refraction error. The main objective of this paper is to demonstrate the elimination of the systematic refraetion effect on trigonometric levelling by applying an appropriate mathematical model based on the available data of solar radiation. The results predicted by the new solution are presented and analyzed attempted to estimate the solar radiation theoretically using different models. Sometimes, this theoretical estimation of hourly values of direct. diffuse and total solar radiation data can be used when the measuring equipment's are not available. In the last few years, Modem Technology in electronics has been used for the accurate measuring of the net and diffused solar radiation. the present paper deals only the measuring data of solar radiation . 

Main Subjects