Development of Methods to Monitor Continuously Operating Reference Station Antenna Stability

144 Pages·2009·16.65 MB·English

University of Southern Queensland
Faculty of Engineering and Surveying

Development of Methods to Monitor
Continuously Operating Reference Station
Antenna Stability

A dissertation submitted by
Tony Camplin

In fulfilment of the requirements of
Course ENG 4111 & ENG 4112 - Research Project

towards the degree of
Bachelor of Spatial Science (Major - Surveying)

Submitted: October, 2009
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Abstract

The uptake of Global Navigation Satellite System (GNSS) technology in a variety of
industries has occurred at a rapid rate. In particular, the use of the Real Time
Kinematic (RTK) differential technique has somewhat transformed the approach to
many traditional tasks requiring accurate positional information.

To maximise advantages provided by this technology, fixed base station antennas
have become prevalent in areas where regular operation is anticipated. These fixed
installations are often found on building rooftops or masts.

Whilst many potential error sources exist in this form of surveying, it is critical that
the position of the reference antenna is accurately known. This research addresses the
positional stability of a reference antenna installed in a permanent application.

The aim of the project was to develop methods to monitor a reference antenna for
stability over a period of time. Several methods, including both terrestrial
observations and GNSS observations, were adopted in the research. A comparative
analysis revealed various characteristics of each method.

The results of the research indicated that terrestrial observation, performed with a total
station, was the most precise monitoring method of those undertaken. However,
results that may be considered acceptable in a particular individual user’s situation
were also obtained through the use of GNSS methods trialled. Limitations associated
with the various methods were also discussed and would need to be considered for
individual applications.
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Certification

I certify that the ideas, designs and experimental work, results, analysis and
conclusions set out in this dissertation are entirely my own efforts, except where
otherwise indicated and acknowledged.

I further certify that the work is original and not been previously submitted for
assessment in any other course or institution, except where specifically stated.

Tony Camplin
Student Number: W0008349

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Signature

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Date
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Table of Contents

Contents Page

Chapter 1 – Introduction
1.1 Problem Statement..................................................................................1
1.2 Research Aims and Objectives................................................................2
1.3 Background.............................................................................................3
1.4 Justification.............................................................................................5
1.5 Research methodology............................................................................7
1.6 Summary.................................................................................................9

Chapter 2 – Literature Review
2.1 Introduction...........................................................................................10
2.2 GNSS Surveying...................................................................................11
2.3 Antenna Stability Issues........................................................................13
2.4 Legal Issues...........................................................................................17
2.5 Current Monitoring Methods................................................................19
2.5.1 Qld DERM SunPOZ......................................................................19
2.5.2 Vicmap Position GPSnet...............................................................20
2.5.3 NSW CORSnet..............................................................................21
2.6 Equipment.............................................................................................22
2.7 Summary...............................................................................................23

Chapter 3 – Research Methodology
3.1 Introduction...........................................................................................25
3.2 Accuracy Requirements........................................................................26
3.3 Measurement Methods..........................................................................26
3.3.1 Terrestrial Observations................................................................27
3.3.2 GNSS Methods.............................................................................32
3.4 Testing Itinerary....................................................................................35
3.5 Network Planning and Site Selection....................................................36
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3.6 GNSS Monitoring Site Layout..............................................................39
3.7 Equipment Configuration......................................................................41
3.8 Processing Methods...............................................................................43
3.9 Data Analysis and Results Presentation................................................46
3.10 Consequential Effects...........................................................................46
3.11 Risk Assessment..................................................................................47
3.12 Resource Analysis...............................................................................48
3.13 Project Timeline..................................................................................48
3.14 Summary.............................................................................................49

Chapter 4 – Results
4.1 Introduction...........................................................................................51
4.2 Data Processing Methods......................................................................52
4.3 Terrestrial Observations........................................................................52
4.4 GNSS Observations...............................................................................55
4.4.1 AUSPOS Results..........................................................................55
4.4.2 Individual Static Baselines...........................................................57
4.4.3 Fully Constrained Network Adjustment......................................61
4.5 DERM results........................................................................................65
4.6 Summary...............................................................................................67

Chapter 5 – Analysis
5.1 Introduction...........................................................................................68
5.2 Terrestrial Observations........................................................................69
5.3 AUSPOS...............................................................................................72
5.4 Individual Static Baselines....................................................................74
5.5 Adjusted Static Network.......................................................................77
5.6 DERM Results.......................................................................................80
5.7 Comparative Analysis of all Methods...................................................83
5.8 Comparison of Method Precision..........................................................86
5.9 Summary...............................................................................................88

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Chapter 6 – Conclusion
6.1 Introduction...........................................................................................89
6.2 Conclusion of Methods.........................................................................90
6.2.1 Terrestrial Observations...............................................................90
6.2.2 AUSPOS......................................................................................91
6.2.3 Individual Static GPS Baselines...................................................92
6.2.4 Fully Constrained Network Adjustment......................................94
6.2.5 DERM..........................................................................................95
6.2.6 Comparison of all Methods..........................................................96
6.3 Close......................................................................................................97

References................................................................................................98

Appendices.............................................................................................103

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List of Figures

Number Title Page

1.1 SunPOZ virtual reference station network 4
2.1 Differential GNSS 11
2.2 Network RTK 12
3.1 Leica AT504GG antenna 28
3.2 Mounting arrangement at IPSW showing ARP 28
3.3 Aerial photograph of terrestrial monitoring
survey stations 29
3.4 IPSW Mounting location on building 30
3.5 Plan of terrestrial stations and observations performed 31
3.6 GNSS Multipath 38
3.7 Static survey monitoring site layout 39
3.8 Leica GNSS receiver at station BOOV 40
3.9 Satellite elevation mask 42

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List of Tables

Number Title Page

2.3 RMS Errors of mechanical vs measured movement 14
for different data spans
2.4 Temporal variation for RMIT on 15/12/2002 16
3.10 IGS ephemeris accuracy and availability 43
3.11 Project timeline 38
4.1 Initial Coordinates for terrestrial observations 52
4.2 Terrestrial observations relative coordinate comparison 54
4.3 ‘GNSS QC’ results for multipath and cycle slip
analysis at station ‘IPSW’ 56
4.4 AUSPOS relative coordinate comparison 57
4.5 GNSS QC’ results for multipath and cycle slip analysis
at stations BOOV, HAIG and POND 58
4.6 Individual Static GPS baseline coordinate comparison 60
4.7 AUSPOS coordination values of monitoring sites 62
4.8 GPS Baseline vector residuals after adjustment 64
4.9 Adjusted MGA94 Coordinates for IPSW 65
4.10 DERM relative coordinate comparison for station IPSW 66
5.1 Standard Deviations of IPSW using terrestrial
observation method 70
5.2 Terrestrial observation relative coordinate differences
for IPSW
5.3 AUSPOS relative coordinate differences for ‘IPSW’ 73
5.4 Individual Static GPS baseline relative coordinate
differences for IPSW 76
5.5 Fully constrained network adjusted relative coordinate
differences for IPSW 79
5.6 Comparison of relative coordinate difference
standard deviations between individual static
baselines and network adjusted results 80
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Number Title Page

5.7 DERM relative coordinate differences for IPSW 82
5.8 Relative coordinate differences in easting –
all methods 83
5.9 Relative coordinate differences in northing –
all methods 84
5.10 Relative coordinate differences in ellipsoidal height –
all methods 85
5.11 Standard deviations of mean results for each
monitoring method 87
6.1 Maximum variations recorded at IPSW using
terrestrial observations 90
6.2 Maximum variations recorded at IPSW using
AUSPOS observations 91
6.3 Maximum variations recorded at IPSW using
individual static GPS baselines 93
6.4 Maximum variations recorded at IPSW using
a fully constrained network adjustment 95
6.5 Maximum variations recorded at IPSW using
DERM results 96

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