Fig. 4From: Accurate analytic approximation for the Chapman grazing incidence functionRelative error as a function of the scale parameter in the asymptotic \(X\le 1\). The curve a corresponds to Eq. (36), the curve b stems from the Kocifaj result (Kocifaj 1996), the curve c is due to Green and Barnum (1963), and the curve d is obtained from Eq. (43). The cases of small (dashed) and large (solid) solar zenith angles are shownBack to article page