144
cos A
d9 ~M
sin A
AT ds (2.1.1)
iv cos 9 r 1
tan 9 sin T
dA ds
In these formulas we denote by
9 latitude
X longitude
A azimuth
s distance
M radius of curvature of the meridian
N radius of curvature of the prime vertical
Further the values of all variables in a point P0 (90, X0, A0, s0 o)
are given. The values of 9, X and A in a point P at a distance s of
P0 have to be computed.
o
H
a
Figure 1.
By dividing the distance s into n parts, the values of the variables
in P can be computed by applying Runge-Kutta n times.
For this computation an algol procedure, named gi6, has been
written (see appendix).
2.2 Some technical aspects of the computation.
Technical aspects are the accuracy, the step size and sometimes
the computing time.
The accuracy is related to a parameter, named eps, of the proce
dure. The procedure tests the computed geographical coordinates
by computing first with a step size of h and after that with a step
size hj2.
