Geoscience Reference
In-Depth Information
Huma and Jilalin and two triangulation points in Suifen River District as the initial
data, and carrying out an adjustment of the first-order triangulation chains in
northeast and east China, the coordinate system achieved by this transfer compu-
tation was designated as the Beijing Coordinate System 1954. So, it follows that the
BJS54 is the extension in China of the Pulkovo Coordinate System 1942 of the
former Soviet Union. However, this extension is slightly different from the Pulkovo
Coordinate System 1942 in the strict sense; for instance, the height anomaly was
estimated by astro-geodetic leveling in China based on the re-adjusted geoid in
former Soviet Union 1955 as the initial value. The geodetic height is referenced to
the Huanghai mean sea level obtained at the Qingdao tidal station, China, in 1956.
Highlights of BJS54 are 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 astro-geodetic orientation.
ʷ
0
and
ʾ
0
are obtained from 900 points
(in
the
former
Soviet
Union)
according
to
2
P
2
900
ʷ ʷ
g
þ ʾ ʾ
g
ﾼ
minimum, where
ʷ
g
and
ʾ
g
are the components
1
of the gravimetric deflection of the vertical obtained by the gravity method. The
geoid separation (geoid undulation) of the geodetic origin N
0
is obtained from
43 points (selected evenly in the former Soviet Union astro-geodetic network)
based on
P
43
N
2
ﾼ
minimum.
1
4. No Euler angles exist:
0.
5. The geodetic origin is located at Pulkovo in the former Soviet Union.
6. The height anomaly is estimated by astro-geodetic leveling in China, based on
the re-adjusted geoid in former Soviet Union 1955 as the initial value.
7. The results of geodetic points are achieved by local adjustments after the
establishment of BJS54.
The Beijing coordinate system 1954 had a tremendous impact on surveying
and mapping. One hundred and fifty thousand national geodetic points and
thousands of military control points, artillery survey control points, and mapping
control points are all calculated based on this coordinate system. The surveying
and mapping results, documents, and data based on BJS54 have been applied in
many fields of economic construction and national defense building. In partic-
ular, the mission of preparing 1:50,000 scale and 1:100,000 scale topographic
maps plotted using BJS54 is almost accomplished. The 1:10,000 scale topo-
graphic maps are also nearly completed.
ʵ
X
ﾼ ʵ
Y
ﾼ ʵ
Z
ﾼ
The deficiencies and problems of BJS54 are as follows:
1. The Krassowski Ellipsoid parameters are different from the modern accurately
defined ellipsoidal parameters, with its semimajor axis being approximately
108 m longer (compared to GRS80).
2. It involves only two ellipsoidal parameters with geometric properties (a, f ) and
cannot fulfill the needs of the four fundamental parameters (semimajor axis a,
Earth gravity field second-order zonal harmonic coefficient J
2
, geocentric
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