Refrakcijos įtakos nustatymas atliekant niveliaciją

Abstract

In this article theoretical principles for computing the refraction influence are considered. In determining the beam at reading staff point the curve of an apparent light beam oscillation is used as basic. Actually, the curve beam ρ is a function of vertical gradient constant of light oscillation refraction. Refraction constant for vertical gradient is expressed by vertical gradients of air temperature, pressure and humidity. In these considerations the formulas of Barrel, Sears and Cauchy and Sellmeier have been used, and then on the basis of the formulas or gained the group oscillation index. The essencial influence of oscillation beam refraction index for vertical gradient was derived. Thus, the vertical pressure gradient is influencing approximately three times less, when the air moisture vertical gradient is fairly unsignificant. The temperature gradient measurement accuracy was determined and then formulas for calculating the refraction correction in station between two points were derived with regard to the required measuring exactness.