Establishment of Geodetic Coordinate Systems - Geodesy: Introduction to Geodetic Datum and Geodetic Systems - page 370

2 3

sinL cosL 00 00

cosB ˁ cosB ˁ

0

4 5

ð N þ H Þ ð N þ H Þ

2
4

3
5 ﾼ

2
4

3
5 þ

dL
dB
dH

Δ X o

cosB
M

sinBcosL
M

sinBsinL
M

00 00 00

Δ Y o

ˁ ˁ

H ˁ þ H þ H þ

Δ Z o

cosBcosL cosBsinL sinB

1980

2 3

0 0

4 5

N

e 2 sin 2 B

:

M 2 ð Þ

a e 2 sinBcosB

00

00

ˁ

sinBcosB ˁ Δ a

ð M þ H Þ

ð M þ H Þ ð 1 f Þ

Δ f

sin 2 B

N
a

M

00 1

e 2 sin 2 B e 2 sin 2 B

1

f ˁ 1

1980

ð 7 : 38 Þ

We have to point out that, while calculating the orientation elements Δ X 0 , Δ Y 0 , Δ

922
1

2

Z 0 based on minimal solution according to ( 7.35 ), the Euler angles

generated by the inconsistency of the axis directions between XAS80 and BJS54
are not taken into consideration. Consequently, the values of

Σ ʾ

1980 ﾼ

Z 0 ,in
the strict sense, are not the three components of the rectangular coordinates between
the ellipsoidal centers O 1980 and O 1954 of the above two geodetic coordinate
systems. Hence, when the values of Δ

Δ X 0 , Δ Y 0 , and Δ

Z 0 of the opposite signs are
transformed into the new BJS54, the ellipsoidal center is O new1954 instead of O 1954 ,
namely the ellipsoidal center of the new BJS54 does not coincide with that of the
BJS54. The difference i, however, very slight.
The geodetic origin of the XAS80 is located in Xi'an. The integrated adjustment
of the nationwide geodetic networks has been carried out based on the geodetic
origin data. In addition, the coordinates in the system of the new BJS54 have been
transformed from the XAS80, and thus the origin of the new BJS54 still remains the
Xi'an origin. However, the geodetic origin data of the two local coordinate systems
are different, which can be calculated according to ( 7.38 ). The result shows that
their geodetic longitudes differ from each other by

X 0 , Δ Y 0 , and Δ

2.19 00 , while geodetic latitudes

differ by 0.39 00 .
Highlights of the new BJS54 can be summarized as follows:

1. It is a local coordinate system.
2. It has adopted the Krassowski Ellipsoid parameters (see Table 4.1 ).
3. It employs the astro-geodetic orientation. The ellipsoidal center approximates
very well that of the BJS54, but they are not coincident with each other.
4. It has well-defined orientation. The minor axis of the Earth ellipsoid is defined as
parallel to the direction from the Earth's center of mass to the polar origin
JYD 1968.0 , and the planes of the initial geodetic and astronomical meridians
are parallel to each other in China, thus ʵ X ﾼ ʵ Y ﾼ ʵ Z ﾼ 0.