Geoscience Reference
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Fig. 5.9 The meridian that
contains point P
Z
X
2
tan B
0
ᄐ
p
:
Y
2
þ
tanB
1
; the
iterations can be repeated until the difference between the two values of B is less
than 0.0001
00
or the difference between the adjacent values of tan B is less than
5
The tanB on the left side (tanB
1
) can be computed. Set tanB
ᄐ
10
10
.
From Fig.
5.9
, in the right triangle PK
p
P
3
, it is apparent that:
p
X
2
Y
2
þ
cos B
ᄐ
H
:
N
þ
Hence, we get:
p
X
2
Y
2
þ
H
ᄐ
cos B
N
:
ð
5
:
22
Þ
Equations (
5.20
), (
5.21
), and (
5.22
) are the expressions for computing L, B, and
H with X, Y, and Z.
Such transformation can be easily understood. The problem is that (
5.21
) needs
iteration. There are many closed formulae for transformation between L, B, H, and
X, Y, Z (see Featherstone and Claessens 2008; Vermeille 2004).
An example of transformation between L, B, H and X, Y, Z is shown in Table
5.1
.
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