Page 100 - Satellite Communications, Fourth Edition

80 Chapter Three

N

ES

R

E
a E
a E
SS d

h

s

Figure 3.1 The geometry used in determining the look angles for a geostationary satellite.

There are six angles in all defining the spherical triangle. The three
angles A, B,and C are the angles between the planes. Angle A is the angle
between the plane containing c and the plane containing b. Angle B is the
angle between the plane containing c and the plane containing a.From

c
B
A
a
b

E C

E SS

(a)

R = 90° + E d
Figure 3.2 (a) The spherical geometry
b related to Fig. 3.1. (b) The plane triangle
s obtained from Fig. 3.1.
a GSO = a + h
E
(b)