Reference Ellipsoid and the Geodetic Coordinate System - Geodesy: Introduction to Geodetic Datum and Geodetic Systems - page 216

Fig. 5.32 Correction for
skew normals

N 2 e 2 sin B 2 N 1 e 2 sin B 1 N 2 e 2 K a K b ﾼ OK b OK a ﾼ ð sin B 2 sin B 1 Þ ,

S cos A 1

M 1

With the differential equation of geodesics B 2 B 1 þ , one obtains:

N 2 e 2 cos B 1 S cos A 1
M 1

K a K b ﾼ :

Inserting back into the above equation and rearranging gives:

e 2 H 2 ˁ

00

cos 2 B 2 sin 2A 1 ,

ʴ 2 ﾼ ð 5 : 56 Þ

2M 2

where B 2 and M 2 are the geodetic latitude and meridian radius of curvature of the
target point, A 1 is the geodetic azimuth of the observed direction, and H 2 is the
height of the target (actual target point in observation) relative to the ellipsoid,
consisting of three parts:

H 2 ﾼ H 2N þ ʶ 2 þ a 2 ,

where H 2N is the normal height of the monument center of target point, ʶ 2 is the