nghiên cứu cơ sở lý thuyết cho việc hiện đại hóa lưới khống chế trắc địa quốc gia ở việt nam bằng hệ thống vệ tinh dẫn đường toàn cầu gnss bản tóm tắt tiếng anh

MINISTRY OF EDUCATION AND TRAINING
HANOI UNIVERSITY OF MINING AND GEOLOGY


BUI THI HONG THAM

RESEARCH ON THE THEORETIC BASE FOR THE
MODERNIZATION OF THE NATIONAL GEODETIC
CONTROL NETWORK IN VIETNAM BY GLOBAL
NAVIGATION SATELLITE SYSTEM GNSS



Specialty: Geodesy and Mapping
Code: 62520503



SUMMARY OF THE THESIS SUBMITTED FOR THE
DEGREE OF DOCTOR


HANOI – 2014
The thesis has been completed at the Department of Geodesy
surveying, of Surveying Faculty, Hanoi University of Mining and
Geology.

Scientific Supervisors:
1. Prof. Dr.Sc. Dang Hung Vo
Association of Geodesy, Maps and Remote Sensing of Vietnam
2. Dr. Vu Van Tri

Hanoi university of Mining and Geology

Examiner 1: Dr. Le Minh
Association of Geodesy, Maps and Remote Sensing of Vietnam
Examiner 2: Dr. Nguyen Dinh Thanh
Defense Mapping Agency of Vietnam - Ministry of National
Defense
Examiner 3: Dr. Tran Hong Quang
Association of Geodesy, Maps and Remote Sensing of Vietnam

The dissertation will be defended at the University examination
Council at the Hanoi University of Mining and Geology, at… h,
……………… 2014


This dissertation is submitted to National library
and library of Hanoi University of Mining and Geology.
1
INTRODUCTION
1. The importance of dissertation
The launching of global navigation satellite system (GNSS)
opened a new era for sciences – technology, especially surveying -
mapping. GNSS has changed basically in the conceptualization and
methodology to position points on the ground due to its advantages.
According to the national controling network, GNSS applications can
be divided into two phases:
- Authenticate, increase points, improve the traditional coordinate
network;
- Establish the national coordinate network under a new concept
based on the ability of GNSS technologies.

Currently, national coordinate network in the world are ordinarily
built on GNSS continuously operating reference stations with
consistent density, appropriated accuracy, reliability, safety and multi
– purposes. This is called the GNSS CORS network. The name
describes technologically "continuous observation to connect points in
an online network system." Density and distribution of points varies
from country to country.
In Vietnam, the traditional network was upgraded preciseness,
improved and modernized by GNSS technology to become national
georeference system VN - 2000. This made a milestone of surveying
and mapping science of our country.
In face of the achievements in the world, it is essential to build
continuously the geodetic coordinate network by GNSS technology to
replace traditional geodetic network and meet the modern demands of
the coordinates. GNSS technology applications are the most basic
component of geographic information infrastructure and become a
trend in the world, so we have to integrate without any other options.
The Ministry of Defense has been executing the project of
constructing the military georeference system GNSS CORS network
(finished on 1/2 block workflows), Ministry of Natural Resources and
Environment has built and implemented Strategy of measuring and
mapping development, of which the modernization of coordinates and
leveling network system is the main point (consideration to approval).
Although there are scientific basis and practical studies to apply, there
has been no thesis which does research in a systematical way of
2
building modern geodetic coordinate network, multi-purposes to meet
the demand and integrate development of geographic information in
the world. "Research on the theoretic basis for the modernization of
the national geodetic control network in Vietnam by global

navigation satellite system GNSS" focuses on the issue.
2. Objective of the dissertation
Provide scientific and practical foundations for the modernization
of geodetic control network of Vietnam, serving multiple purposes
(surveying - mapping, navigation, researching on modern crustal
movements, international information integration, ) based on GNSS
technology.
3. Subjective of the dissertation
The subjective of the dissertation is the national control network
in Vietnam and the applications of GNSS technology.
4. Scope of the dissertation
In terms of science: Feasibilities of GNSS technology (global,
continuous-time, methods of measurement, accuracy, reliability,
achievements and international experience, ). Data processing of the
actual stations continuously demonstrates how to connect coordinates,
define and coordinate transformation, velocity of movements in the
international coordinate systems ITRF. Solutions, methods to build the
geodetic network are to establish a unified coordinate base in
surveying and mapping, solve the problem of positioning reference
system and scientific research to Earth.
In terms of space: The national geodetic coordinate network can
connect with the international coordinate network IGS.
In terms of time: It is counted since Vietnam constructed the
traditional geodetic network
5. Contents of dissertation
To achieve this goal above, the dissertation must solve the
following issues:
- Evaluate overview of GNSS technology applied to build national
geodetic network.
- Study the ability of GNSS technology, new measurement

methods, especially the group of methods to measure real time area.
- The format (structure and density) GNSS CORS network
serving the purpose of geodesy and mapping (basic terrain mapping,
3
cadastral and construction), monitoring crustal movements, building
the national reference system according to the dynamic point of view.
- Process data of measurements of national GNSS CORS network
simultaneously with IGS data to link international coordinates, update
on coordinates according to the dynamic reference system point of
view, and observation of modern crustal movements.
6. The methodology
The dissertation using the following methodologies:
- Methods of synthesis, analysis and inheritance: Collect the
historic documents; update the information on the internet, synthesis,
analysis of resources and research results, inherit selectively
achievements related to the subject.
- Methods of collection and processing GNSS data: static
measurements, session 24/24 at the continuous measurement points.
Processing of measurements and IGS data by Bernese 5.0 software,
connect coordinates, velocities with IGS network, scalability
coordinates, and velocities in the typical dynamic coordinates system
ITRF.
- Methods of comparisons: Compare the advantages and
disadvantages of building geodetic control network according to the
traditional method and the method using GNSS technology.
- Methods of expert: Learn more knowledge and experience from
experts.
- Method of application of information technology: using
programming languages; setting up spreadsheets to automate the
calculation process.

7. Scientific and practical meaning of dissertation
- The scientific meaning of dissertation: Approach a further step
when to learn about the development of GNSS technology and
provides reliable scientific foundations of GNSS technology
applications in building modern geodetic coordinate network, multi -
purpose consistent with the reality in Vietnam and connect with the
world.
- The practical meaning of dissertation: The results of the
dissertation have contributed to the selection of the appropriate
solution to modernization geodetic coordinate network, reference
system in Vietnam.
4
8. Rational arguments and new contributions
a. Rational arguments
- First argument: According to a new point of view, National
coordinate network in Vietnam is GNSS CORS network with
appropriate infrastructure (receiver, antenna, augmentation systems,
information infrastructure, network connectivity, ) meeting modern
measuring methods; solving the task of defining and maintaining the
coordinate reference system; the detailed measurement for setting up
mapping; tracking and navigation; researching on modern crustal
movements.
- Second argument: because of the structure and density of the
GNSS CORS network, methods of collecting and processing relevant
data, the national network entirely meet the needs of the surveying and
mapping, international connections of geographic information; carry
out Earth scientific research in Vietnam according to global standards.
- Third argument: The national geodetic coordinate network in
Vietnam based on GNSS technology has high performance (advanced
accuracy, extend technical scope, timely updates and automation).

b. New contributions
- To put forward a GNSS CORS network in Vietnam with full
scientific and practical foundations.
- To prove the necessity of building a dynamic reference system
in Vietnam by specific data.
- To propose the time to update the new coordinates for the GNSS
CORS network in Vietnam.
- To put forward the workflow of coordinate transformation,
velocities of GNSS points between international terrestrial reference
frames ITRF using 14 transformation parameters.
- To establish the velocity diagram of GNSS points in Vietnam in
a coordinate system.
9. Structure of dissertation
The structure of dissertation includes three main parts:
introduction, content as well as conclusions and
recommendations, which is presented on 132 pages, 25 drawings
and diagrams, 34 tables.
5
Chapter 1
OVERVIEW OF APPLICATION OF GPS TECHNOLOGY
IN BUILDING COORDINATE NETWORK SYSTEM
1.1. Application of GNSS technology in the construction of
geodetic network in the world
GNSS has become a major technology and has gradually replaced
the traditional measurement technology in the construction of geodetic
network.
1.2. Application of GNSS technology in the construction of
geodetic network in Vietnam
From the overview picture of the development of GNSS
technology in the world and the process of applying GNSS technology

in Vietnam, it can judge the trend of GNSS technology applications in
Vietnam. Specifically, GNSS technology helps reduce working time
with low cost and high-tech capabilities. Furthermore, it provides
favorable conditions to change significantly the conceptions and forms
of the national coordinate control network, specifically including:
- Formatting many tiers with dense buried points of the traditional
manner has been replaced by the form of the base GNSS CORS
network with very little buried points, which creates a new method of
determining the number and distribution of buried points at the last
grade for measuring detailed topography, objects. This is a new form
of national coordinate control network; we have not approached "The
Concept of No - Network Geodesy" but access "low density geodetic
network ".
- It is possible to identify the local geoid model with high
accuracy, the combination of coordinate and leveling network in a
GNSS CORS network measured leveling is a new approach to
unified coordinates - leveling control network.
- The dynamic geodetic GNSS network depending on time is a
new approach to the national georeference system, suites Earth
observation associated with the new tectonics. The application of this
approach in each country associated with the international reference
system requires detailed studies.
Therefore, the direction researching of the dissertation has been
laid out and presented in section 5. Content of dissertation in the
beginning of the dissertation.
6
Chapter 2
STUDYING THE POSIBILITY OF GNSS TECHNOLOGY
APPLICATIONS TO CHANGE THE NATIONAL HORIZONTAL
NETWORK IN VIETNAM

2.1. The general problem
2.1.1. Conception changes of form, structure, precision of control
network since the GNSS technology was born
- Changes of the application structure of GNSS

Figure 2.1. The application structure of GNSS technology [50]
Currently, there have been fundamental changes in GNSS in terms
of technology on promoting positioning under the new approach. With
the present concept, the application structure of GNSS technology is
expanded (Figure 2.1).
- Development trends of measurement methods.
The principle of measuring real-time NRTK starts with all
reference stations in these network online observing satellites
continuously with the software system installed on the master system
of NRTK center.
GNSS
Augmentation system
User segment
Basic system
Control
segment
SBAS
receivers
software
Space
segment

GPS
GLONASS
GALILEO

EGNOS
WAAS
MSAS
EUPOS
SAPOS
…
GBAS
…
…
COMPASS
…
…
7
The aim of NRTK is to minimize the impact of the error depended
on the distance and location calculated within the network.
Minimizing sources of error in the measurement process is different
when the technology used NRTK in is different (MAC, FKP, VRS, ).
Each technology will lead to significant differences in performance,
reliability and accuracy for rover stations.
- Geodetic control network under the new perspective is
integrated geodetic points, based on the existing geodetic
infrastructure of each country and GNSS technology to exploit
efficiently for practice and scientific research. The network is based on
the following principles:
+ The network must be durable and long lasting;
+ Reasonable density, data in the plane reference, leveling and
gravity system;
+ To be the basis for national geodetic reference system;
+ To meet the applications when using of modern surveying
technology.

As a result, geodetic control network under standpoint ensures the
capacity to provide data about the shape, size, gravity field of the
Earth, as well as the volatility of quantities over time. This network
has the following tasks:
- Navigation and tracking: error millimeters.
- Surveying and mapping: error position about centimeters.
- Research and identify crustal movements: error millimeters.
- Supporting research atmosphere,
2.1.2. The method of construction GNSS CORS network playing
basic geodetic plane network in the world and Southeast Asia
Today, so many GNSS CORS networks have been established in
the world, which are the major infrastructure to provide the necessary
applications with high accuracy in surveying, mapping, navigation and
the Earth science applications. The countries which have set GNSS
CORS network have to follow the legal and the rules of the countries.
Moreover, the countries with great potential of sharing the network
also cooperate to form GNSS CORS networks of the region.
8
2.1.3. Some features when building GNSS CORS network
The main advantages of the GNSS CORS network: reducing
depended error sources due to the connection of the permanent stations
to produce the network, the longer distances of points in the GNSS
CORS network results in decreasing the number and density of the
points, and automating the GNSS measurements referencing ,
calculation results to unified reference frame.
2.2. The ability to change the horizontal control network in
Vietnam by the method of construction GNSS CORS network
The control plane network in Vietnam in the future will be the
GNSS CORS network (NRTK CORS), which has distance and
appropriate accuracy to satisfy most missions.

Table 2.1. The number of GNSS CORS stations in Vietnam
N
0
Distance of a GNSS
CORS (km)
Control area of a GNSS
CORS (km
2
)
The number
GNSS CORS
1
20
346
959
2
40
1386
239
3
50
2165
153
4
60
3118
106
5
70
4244

78
6
80
5543
60
7
90
7015
47
8
100
8660
38
9
150
19486
17
10
200
34641
10
11
250
54127
6
2.3. Construction GNSS CORS network in Vietnam
2.3.1. The idea of the tier the national GNSS CORS network,
structure, density and accuracy
The idea of construction GNSS CORS network in Vietnam must
be multi-purposes network service, and satisfy most missions

presented in Table 2.2.
9
Table 2.2. Mission and accuracy requirements of the national GNSS
CORS network
N
0

Mission
The accuracy
requirements
1
To satisfy the requirements of measurement
basic maps as terrain mapping
≤ 10 cm
2
To satisfy the requirements of cadastral
≤ 4 cm
3
To satisfy the requirements of navigation and
tracking
≤ 3 m
4
To satisfy the requirements of researching
modern crustal movements
about mm
5
To satisfy the requirements of establish the
national geodetic reference
about mm
6

To connect with IGS, the network has some
points of attributes IGS to resolve international
scientific tasks regionally and globally
about mm
To form the national GNSS CORS network serving multi-
purposes, the ideas of designing network are proposed:
- Calculation 0f number of points in the GNSS CORS network
bases on missions and accuracy requirements of each tier in the
network.
- The sum of the national GNSS CORS network is calculated
when this network satisfies the requirements of measurement basic
maps - the third GNSS CORS stations.
- Some of the third GNSS CORS stations will be selected to meet
the mission of the first and the second GNSS CORS stations.
- Some of the second and the third GNSS CORS stations will be
selected to meet the mission of the first stations.
- One GNSS CORS station is able to satisfy many different tasks.
Table 2.3. Recommended the number of GNSS CORS stations
Vietnam
Area
(km
2
)
Distance
(km)
Control area of a
GNSS CORS
(km
2
)

The number
GNSS
CORS
The key
economic
region
67150.2
50
2165
39
other areas
264547.8
80
5543
48
The total number of GNSS CORS stations
79
10
The national geodetic control network will be modernized by
GNSS CORS network with minimum and reasonable density of
points, consistent and sustainable, including 79 points, in which:
- 4 points join to IGS - tier 1;
- 8 satisfy the requirements of setting up the national geodetic
reference Reward - tier 2;
- 11 satisfy the requirements of researching modern crustal
movements - tier 2;
- 4 points has DGPS service functions that satisfy the
requirements of navigation and tracking - tier 3;
- 79 points satisfy the requirements of measurement basic maps -
tier 3.

* Comment
Figure 2.2 shows that the application of GNSS technology has
changed the traditional network in both structure and density. The new
one is multi-purpose network; satisfies the requirements of modern
surveying; guarantees for solving the task of verifying and maintaining
the reference frame, coordinate system; satisfies the requirements of
measurement basic mapping; navigation and tracking; researching
modern crustal movements.
79 points in the national GNSS CORS network are designed on
the base map of Vietnam. Some points in the network serve many
objectives when building the GNSS CORS (eg. points in MongCai
cover five functions: join IGS, build the national geodetic reference
frame, research modern crustal movements, navigation and tracking
and serves basic mapping).
In the process of building the national modern geodetic network,
some points in VN - 2000 satisfying the requirements will be selected
as the points of the national GNSS CORS. These points in two
networks will serve for the determination of coordinate transformation
parameters. This will ensure that close link between the old and new
network as well as the unified use of two networks.
The above analysis proves the capacity and accuracy of GNSS
technology in the current period, shows technical efficiency (improves
11
the accuracy and expands the technical scope, timely updates,
automation, ) indisputable of this technology when applied for the
construction of the national geodetic network in Vietnam.

Figure 2.2. The GNSS CORS network in Vietnam
Note: : Function set up the national reference frame; :
Research function geodynamics; : DGPS function; : Joined on

IGS. The green area indicates three main economic Northern, Central,
Southern. The green lines separate territorial Vietnam into blocks
according to the documents [6].
2.3.2. Principles of organization, construction and operation of
GNSS CORS network
Each GNSS CORS station has minimum requirements on many
aspects of the construction process and operation.






16
0

104
0

108
0

112
0

116
0

20
0

12
0

8
0

TRUNGQUOC
THAILAN
Hainam
HoangSa Islands
(Vietnam)
CAMPUCHIA
MALAYSIA
TruongSa Islands
(Vietnam)
12
Chapter 3
THE NATIONAL HORIZONTAL NETWORK FOR MORDEN
CRUSTAL MOVEMENTS RESEARCH
3.1. Scientific and practical significance of researching modern
crustal movements in intercontinental and global scale
Over time, GNSS technology is growing and perfect, problems of
geometry and physics of the Earth is resolved. Until now, this
technology has completely satisfying scale of studies, the accuracy
required for the job posting. This is the basis to take form concepts of
dynamic geodetic.
3.2. The network monitors modern crustal movements and
achievements when applying GNSS technology
The determination of the Earth's crustal movements requires the

highest accuracy and compliances with rigorous technical process at
any scale. Presently, the realities have demonstrated that this
technology can fully satisfy the accuracy requirements.
3.3. Monitoring modern crustal movements in Vietnam
In Vietnam, the monitoring system using GNSS technology has
been implemented to create a database growing richer. These findings
have contributed to geodynamic map of the region in more detailed,
accurate and reliable way.
3.4. Adjustment DGPS/CORS on the international reference
system
3.4.1. Measurement data
Table 3.1. Synthetic measurement data
N
0

Day
DOY
Name of points
MCRS
DNRS
PQRS
TSRS
KUNM
NTUS
PIMO
WUHN
1
1/12/2010
335
x

x
x

x
x
x
x
2
2/12/2010
336
x
x
x

x
x
x
x
3
3/12/2010
337
x
x
x

x
x
x
x
4

4/12/2010
338
x
x
x

x
x
x
x
5
1/6/2011
152
x
x
x
x
x
x
x
x
6
2/6/2011
153
x
x
x
x
x
x

x
x
13
7
3/6/2011
154
x
x
x
x
x
x
x
x
8
4/6/2011
155
x
x
x
x
x
x
x
x
9
5/6/2011
156
x
x

x
x
x
x
x
x
10
1/3/2012
61
x

x
x
x
x
x
x
11
2/3/2012
62
x

x
x
x
x
x
x
12
3/3/2012

63
x

x
x
x
x
x
x
13
4/3/2012
64
x

x
x
x
x
x
x
14
5/3/2012
65
x

x
x
x
x
x

x
3.4.2. Download international support information and data
All the support information and data: Precise ephemerides of
satellite’s internal orbital model, Earth’s rotation axis data, and global
ionosphere model, etc. are exploited from IGS.
3.4.3. Processing software
DGPS/CORS data collected will be processed by the Bernese 5.0
software processes closely follow the menu.
3.4.4. Steps
Results for the network computing processor were
synthesized following tables.
Table 3.2. Coordinate of points
N
0
Point
X (m)
Y (m)
Z (m)
1
DNRS
-1915754.4967
5824431.0548
1750989.0477
2
MCRS
-1831172.4798
5646418.0114
2325703.8077
3
PQRS

-1521499.8762
6094084.7056
1104443.9268
4
TSRS
-2354092.2732
5850302.4095
952491.9085
Table 3.3. Absolute velocity of points DGPS/CORS
N
0
Point
V
B
(mm/y)
V
L
(mm/y)
V
H
(mm/y)
V
(mm/y)
Azimuth
(
0
)
1
DNRS
34.7

-20.5
44.9
40.3
120.6
2
MCRS
30.8
-7.8
-1.8
31.8
104.2
3
PQRS
21.1
-12.2
11.7
24.4
120.0
4
TSRS
20.2
-13.5
-6.0
24.3
123.8

14

Figure 3.1. Diagram velocity vectors movements of points DGPS/CORS
* Comments

- Thus, the national DGPS CORS network has been computed
processed and connected to IGS. Measurement and support data were
selected to fully satisfy the task of establishing geodetic reference
frame and identify modern crustal movements during the processing.
- The process was carried out according to strict procedures.
- The velocity of points: MCRS (MongCai), DNRS (DaNang),
PQRS (PhuQuoc) and TSRS (TruongSa) determined by the integration
of standard equations is about 3 cm/year. Error of the vertical and
latitude, longitude velocities are approximately 3 mm/year and 1
mm/year, respectively. The result is high accuracy in comparing to the
3 cm velocity.
- Movements in the different regions of the territory are various:
40.3 mm/year in the Central region (the largest value), and the velocity
movement in the MongCai is faster than PhuQuoc and TruongSa 31.8
LAO
TRUNGQUOC
THAILAN
HoangSa Islands
(Vietnam)
CAMPUCHIA
MALAYSIA
TrươngSa Islands
(Vietnam)
(TB-BTB)
(NTB-NB)
Hainam
(ĐB
)
(MT
)

(BIENDONG)
16
0

104
0

108
0

112
0

116
0

20
0

12
0

8
0

MCRS
DNRS
PQRS
TSRS
100 km

30 mm/year
MALAYSIA
15
mm/year. The modern crustal movements are similar in PhuQuoc area
and TruongSa Islands.
- The velocity vectors indicated the study area tends to movement
towards Northwest – Southeast connecting to the other published
results both in direction and value.
- In addition, the results also give the coordinates of the points in
the ITRF05 reference frame related to international time 2010 - 03-04
00:00:00. The software also allows determining coordinates in relation
to any selected point.
- The velocity vector obtained through the processing practically
of the dissertation is recognized as a scientific contribution to research
modern crustal movement map on the territory of our country.

Chapter 4
CONSTRUCTION OF THE NATIONAL HORIZONTAL REFERENCE
SYSTEM ACCORDING TO DYNAMIC POINT OF VIEW
4.1. The process of forming the dynamic geodetic reference system
in the world
The implementation of the ITRS is to determine International
Terrestrial Reference Frame (ITRF) with 7 parameters including 3
parameters of original geocentric, 3 of axis orientation angle
parameters and 1 parameter of the difference in length. These
parameters are updated base on the observation data every year. It is
necessary to consider the rate of change of the 7 parameters because
they are always in a state of dynamic (Earth exists in the dynamic)
.Thus, a number of parameters is 14.
4.2. The necessity of the construction of the dynamic reference

system in Vietnam
4.2.1. Overview of the national horizontal reference system VN - 2000
The reference system and the national horizontal system VN -
2000 is the initial result steps of the modernization of the national the
horizontal network and the national horizontal system in Vietnam.
4.2.2. The necessity of the construction of the dynamic reference
system in Vietnam
The GNSS CORS network being basic elements to create the
dynamic coordinate system will be built in our country. The
16
national coordinate system changes over time; however, coordinates of
points in the national GNSS CORS network serving on measurement
basic maps must be published at the time of determined. Over time,
coordinates of GNSS CORS have changed. When coordinates of these
points in new time compared with its coordinates at time published
that beyond a limit will so the GNSS CORS network does not satisfy
accuracy for the measurement basic map. As a result, coordinates of
points in the national GNSS CORS network used must be updated -
coordinates at the new time.
Therefore, to study the need to build the national dynamic
coordinate system in Vietnam by measurement data, velocity deviation
movements of tectonic blocks will be calculated, its consequences is
recommended reasonable time to update the national GNSS CORS
network.
Table 4.1. Velocity deviations between tectonic blocks
Year
Velocity deviation movements of tectonic blocks (mm)
DB and TB - BTB
TB - BTB and NTB - NB
TB - BTB and BĐ

d
max
1
8.5
15.9
16
16
2
17
31.8
32
32
3
25.5
47.7
48
48
4
34
63.6
64
64
5
42.5
79.5
80
80
6
51
95.4

96
96
7
59.5
111.3
112
112
8
68
127.2
128
128
9
76.5
143.1
144
144
10
85
159
160
160
Note: North East (DB); North West - North Central (TB - BTB);
Sea East (BD), South Central - South (NTB - NB).
Indeed, coordinates of GNSS points are significantly affected by
the deformation of the crust or plate tectonic movement. Calculation
results are evidence to the need to build the reference system in
Vietnam.
17
The dynamic reference frame is always changing over time, so the

period of updating the coordinates of the GNSS CORS network is
reasonable by calculation specifically. There are two reasons for this;
firstly, if the update of coordinate is not done, the GNSS network will
be deformed and do not guarantee the accuracy of the measurement of
basic maps; secondly, if its updating is always done so difficult for
measurement mapping, economically costly.
To propose the updating time for the new national coordinate
GNSS CORS network guaranteeing for surveying terrain mapping
1:500 in all conditions (barren or bushy area), the dissertation choices
maximum error 100 mm.
The deviation presented on table 4.1 shows that movement
velocity of the largest annual tectonic blocks in the 6
th
and 7
th
years are
96 mm and 112 mm, respectively; meaning the velocity in 7
th
year
(d
max
) is greater than 100 mm. Therefore, the interval of time required
to update the new coordinate for the national GNSS CORS network is
recommended 7 years.
4.3. Construction of the dynamic reference system in Vietnam
The GNSS CORS network is the realization of the national
coordinate system according to the dynamic view. This network will
maintain the national geocentric coordinate frame 3D and support for
in real-time positioning, navigation and monitoring applications. In
addition, measuring precision leveling, measuring gravity points in its

network will form a unified the national network on plane, leveling
and gravity, which is the basis for building the precise accuracy geoid
model in Vietnam.
4.4. The way uses the geodetic reference system in the practice
4.4.1. transformation Formula system
4.4.2. Build flowchart of coordinates and velocities transformation of
GNSS points between two dynamic coordinate systems
18

Figure 4.1. Process coordinates transformation from ITRF
(1)
at time t
0
to ITRF
(2)
at time t

Figure 4.2. Process transfer velocity from ITRF
(1)
to ITRF
(2)

14 parameters
ITRF(t
0
)
(1)
ITRF(t)
(2)

(t - t
0
)

)2(
ITRFZYX
)V,V,V(

)2(
ITRFZYX
)V,V,V(

)2(
ITRFHLB
)V,V,V(

)1(
ITRFHLB
)V,V,V(

X(t
0
)
(1)
X(t)
(1)
)1(
ITRFHLB
)V,V,V(

X(t
0
)
(1)
X(t)
(1)
14 parameters
ITRF(t
0
)
(1)
ITRF(t)
(2)
(t - t
0
)
)1(
ITRFZYX
)V,V,V(

X(t)
(1)
X(t)
(2)
19
4.4.3. Empirical calculations
Table 4.2. Coordinates of GNSS points in ITRF08 at 18/07/2012
N
0
Point

X (m)
Y (m)
Z (m)
1
XUYO
-1606525.3107
5700807.4794
2358910.3445
2
OAN0
-1566459.7943
5711793.1162
2359391.0194
3
DOI0
-1554911.1281
5722287.9981
2341248.9526
4
SOC1
-1621267.4901
5719456.3583
2303158.3259
5
TAM2
-1601083.2914
5719707.1284
2318672.4007
6
HUN1

-1571100.2652
5731225.1349
2308717.3752
7
NTHO
-1555548.8832
5730756.5177
2320416.1883
8
SON1
-1557982.9310
5741852.5798
2291130.9723
9
LAP1
-1541103.3835
5738426.8455
2311048.3542
10
BAVI
-1578207.2652
5740266.8121
2281398.4277
11
HOA1
-1561203.3469
5754853.9430
2257478.9710
12
NAM0

-1480436.1083
5741958.4656
2342822.2803
13
NGA1
-1353072.7825
5749668.0049
2402462.2895
14
HAM1
-1355321.3541
5762376.1094
2367436.5756
15
DON1
-1334851.1103
5758491.9047
2387972.1199
16
LEM1
-1335854.0006
5773067.2098
2353215.1336
17
MON1
-1464209.0062
5767238.2661
2291232.1061
18
NOI1

-1457371.9564
5771322.4579
2285116.1053
19
LOT1
-1445752.0185
5771190.8986
2292523.2300
20
QTA2
-1432563.6411
5770244.6106
2303209.1292
21
NAD2
-1458337.9705
5777358.5267
2270039.5502
22
DIEB
-1336842.3829
5787988.4739
2315702.2299
23
DOSN
-1724757.3380
5714523.9160
2239792.0393
24
NT01

-1726969.5917
5714864.9568
2237081.3908
25
NT03
-1844373.6094
5997105.5965
1142317.0439
26
NT04
-1575936.5479
6075089.2127
1132070.0742
27
QT01
-1339440.8883
5788398.0139
2313170.2549
20
28
QT03
-1916791.4419
5822974.9368
1754668.6848
29
VUNT
-1849617.0276
5995299.9136
1143372.7201
30

CAMP
-1772774.5625
5687232.9039
2271331.8300
31
NONN
-1921866.9957
5823665.8416
1747139.7398
32
DNRS
-1915754.6080
5824431.1345
1750989.0334
33
MCRS
-1831172.5471
5646417.9871
2325703.7915
34
PQRS
-1521499.9300
6094084.7200
1104443.9070
35
TSRS
-2354092.3105
5850302.3783
952491.8786
Table 4.3. Absolute movement velocities of the GNSS points in

ITRF08
N
0
Point
V
L

(mm/y)
V
B

(mm/y)
V
H

(mm/y)
V
(mm/y)

Azimuth
(
0
)
1
XUYO
-10.8
35.1
0.6
36.7
107.1

2
OAN0
-10.2
33.6
-13.9
35.1
106.9
3
DOI0
-10.1
33.8
-10.4
35.3
106.6
4
SOC1
-10.2
33.0
-1.7
34.6
107.2
5
TAM2
-10.5
32.5
-0.5
34.2
107.9
6
HUN1

-10.0
33.2
-5.1
34.7
106.8
7
NTHO
-10.5
33.4
-10.6
35.0
107.4
8
SON1
-10.4
32.9
-3.6
34.5
107.5
9
LAP1
-10.9
33.0
-4.7
34.8
108.3
10
BAVI
-9.4
32.2

-1.2
33.6
106.3
11
HOA1
-9.6
34.0
-2.7
35.3
105.8
12
NAM0
-10.3
35.2
3.3
36.7
106.3
13
NGA1
-8.0
39.2
12.2
40.0
101.5
14
HAM1
-8.8
33.0
15.4
34.2

104.9
15
DON1
-10.4
35.3
15.3
36.8
106.4
16
LEM1
-9.4
34.9
12.0
36.2
105.1
17
MON1
-11.7
32.5
-1.0
34.6
109.8
18
NOI1
-10.4
33.1
-4.3
34.7
107.4
21

19
LOT1
-11.9
33.6
-6.1
35.7
109.5
20
QTA2
-10.8
34.0
-9.5
35.7
107.6
21
NAD2
-10.4
32.5
-10.1
34.1
107.7
22
DIEB
-9.6
27.3
4.0
28.9
109.4
23
DOSN

-8.0
27.6
16.7
28.8
106.2
24
NT01
-11.7
36.3
7.6
38.1
107.9
25
NT03
-11.7
27.1
18.8
29.5
113.4
26
NT04
-9.8
15.9
-14.5
18.6
121.6
27
QT01
-10.3
30.2

-19.9
31.9
108.8
28
QT03
-15.0
26.9
-2.6
30.8
119.1
29
VUNT
-11.1
22.8
1.0
25.4
116.0
30
BDE1
-14.1
22.6
0.5
26.6
122.0
31
DTE1
-11.6
24.1
3.1
26.8

115.7
32
BLO1
-14.1
24.1
2.6
27.9
120.3
33
ALO1
-15.4
29.5
19.5
33.2
117.6
34
LNI1
-13.5
26.1
3.9
29.4
117.3
35
THN1
-13.2
25.5
2.7
28.7
117.4
36

BLV1
-14.7
27.7
-0.3
31.4
118.0
37
LANG
-12.5
38.3
-22.6
40.3
108.1
38
DOHO
-9.1
24.9
-15.1
26.5
110.1
39
HUES
-19.8
30.0
10.2
35.9
123.4
40
STT1
-10.3

21.9
-7.5
24.2
115.2
41
CDA1
-7.4
20.7
-9.6
22.0
109.7
42
HOCM
-11.5
22.0
-3.0
24.8
117.6
43
CAMP
-4.4
47.7
28.1
47.9
95.3
44
NONN
-0.2
44.5
24.6

44.5
90.3
45
DNRS
-20.5
35.0
45.0
40.6
120.4
46
MCRS
-7.8
31.0
-1.8
32.0
104.1
47
PQRS
-12.1
21.4
11.8
24.6
119.5
48
TSRS
-13.5
20.4
-5.9
24.5
123.5

22
* Establish diagram the absolute movement velocities on the
territory of Vietnam
coordinates and velocity of some GNSS points on the territory of
Vietnam transferred from ITRF94, ITRF00, ITRF05 to ITRF08 on
18
th
, july7, 2012 base on Vietnam and international data. The results
are shown in Figure 4.3. The transformation method allows applying
to coordinate and velocity between the dynamic national reference
frame (eg. tied to ITRF).
This result is not only theoretical but also practical contribution to
the study of modern crustal movements and construction of the
dynamic coordinates system in future in our country.

Figure 4.1. The diagram of movement velocities of GNSS points


LAO
16
0

104
0

108
0

112
0

116
0

20
0

12
0

8
0

TRUNGQUOC
THAILAN

HoangSa Island
(Vietnam)
CAMPUCHIA
MALAYSIA
TruongSa Islands
(Vietnam)
100 km
30 mm/year
23
CONCLUSIONS AND RECOMMENDATIONS
A. Conclusion
Based on the study of the theory and results of infrastructure
processing data presented in the dissertation, the PhD student has
some remarks:

(1) The dissertation gives overview of infrastructure development
process of geodetic engineering in the world and Vietnam.
Construction of the GNSS CORS network and the support techniques
is a vital trend of all countries to reach the real-time kinematic and
multi- purposed network in the way of the dynamic geodetic network
4D without datum points.
(2) It is necessary to modernize the geodetic control network of
Vietnam according to new trends (GNSS CORS network) to satisfy
multi-purposes: requirements of measurement of basic maps,
navigation and tracking, modern crustal movements, setting up the
national geodetic reference and connect to IGS.
(3) The GNSS CORS network includes 3 tiers with total 79
points: 4 points on IGS participation; 8 point setting up the national
geodetic reference; 11 points serves for research modern crustal
movements, 4 points function navigation and tracking and 79 points
serves for measurement basic maps. A point can satisfy many different
tasks.
(4) The data at 4 points in the national GNSS CORS network
located on 4 plate blocks: North East, North West - North Central,
South Central - South and South Sea are adjusted in the international
coordinate system. The results showed that movements of points on
the plate blocks in Vietnam are uneven. The analysis and calculation
based on the real data prove necessity of build the dynamic coordinate
reference frame in our country.
(5) Coordinates of the national GNSS CORS network will be
published each term to serve for surveying basic maps. If the
difference of coordinates between the new date and the published date
is greater than allowed threshold, coordinates of GNSS CORS points
used will be the later value. The dissertation researched a case and
recommended updated interval of time the new coordinate for the

national GNSS CORS network.