10-1 General mapping equations 275
X
Z
Y
Φ
y = f (Φ)
x = RΛ
p
image of the equator
image
of the
meridian
O
p
P
y
Λ
O
x
(2)
(1)
Fig. 10.2. Principle for constructing a cylindrical map projection in the polar aspect (tangent cylinder:
Φ 0 = 0
◦ ). Greenwich (1) and equator (2).
X
Z
Y
Φ
y = f (Φ)
x = RΛ cos Φ 0
p
image of the equator
image
of the
meridian
O
p
P
y
Λ
O
x
(2)
(1)
(3)
(4)
Fig. 10.3. Principle for constructing a cylindrical map projection in the polar aspect (secant cylinder:
Φ 0 = ±30
◦ ). Greenwich (1) and equator (2). Φ 0 = const. (3) and −Φ 0 = const. (4).