Provision of SBAS/RTK/GNSS Static Positioning Services ...

PHS Contract No: PHS-20-009-PPA Client Quote No: SLA1-003

Project Name: PROVISION OF SBAS/RTK/GNSS STATIC POSITIONING SERVICES

Document Title: SURVEY REPORT

Document Ref.: PHS-20-009-PPA-R001

Rev No. Date Issue Purpose Prepared Checked Approved

A 09/06/20 Issued for Internal Review JB NH/GR JB

0 11/06/20 Issued for Client Review JB JB JB

1 21/09/20 Issued after Client Comments JB NH JB

Contractor

Precision Hydrographic Services Pty Ltd

10 Ragless St

St Marys, SA

Australia 5042

Tel: +61 (0)8 7120 2211

[email protected]

Client

Pilbara Ports Authority – Port Hedland

Locked Bag 2

Port Hedland, WA

Australia 6721

Tel: +61 0 (8) 9173 9000

[email protected]

PILBARA PORTS AUTHORITY

Provision of SBAS/RTK/GNSS Static Positioning Services

HYDROGRAPHIC SURVEY REPORT

mailto:[email protected]

mailto:[email protected]

PHS-20-009-PPA-R001-Rev1 1

Pilbara Ports Authority Provision of SBAS/RTK/GNSS Static Positioning Services

Survey Report May 2020

SUMMARY OF REVISIONS

Revision Date Actioned by

Summary

A 09/06/20 JB Issued for Internal Review

0 11/06/20 JB Issued for Client Review

1 21/09/20 JB Issued after Client Comments

COMPANY DESCRIPTION PHS is a specialist hydrographic survey company with offices located in South Australia and the Pilbara. PHS specialise in conducting high accuracy hydrographic survey services supervised and approved by AHSCP certified Level 1 hydrographic surveyors. PHS has experience in all facets of producing high resolution multibeam surveys for safety of navigation, dredging and maintenance operations. PHS surveys are conducted to meet local, national and international standards. www.precisionhydrographic.com.au

Precision Hydrographic Services Pty Ltd operates under Quality and Safety Management Systems certified ISO 9001:2015 and ISO 45001:2018 by ECAAS (JAS-ANZ registered).

http://www.precisionhydrographic.com.au/

2 PHS-20-009-PPA-R001-Rev1



TABLE OF CONTENTS A. INTRODUCTION ......................................................................................................................................... 5 B. BACKGROUND ........................................................................................................................................... 5

B.1 SBAS TEST-BED PROJECT ...................................................................................................................... 5 B.2 DISCONTINUATION OF AMSA DGPS ....................................................................................................... 5 B.3 SINGLE/ DUAL FREQUENCY AND GNSS/GPS EXPLAINED ............................................................................. 6 B.4 STATISTICAL ANALYSIS ........................................................................................................................... 6

C. EXECUTIVE SUMMARY .............................................................................................................................. 7 D. CONCLUSION ............................................................................................................................................. 8 E. STATIC TEST METHODOLOGY .................................................................................................................... 9 F. EQUIPMENT ............................................................................................................................................ 10

F.1 STATIC TEST EQUIPMENT ..................................................................................................................... 10 F.2 RTK BASE STATION EQUIPMENT ........................................................................................................... 10 F.3 SOFTWARE ........................................................................................................................................ 10

G. DATUM AND CONTROL ........................................................................................................................... 11 G.1 HORIZONTAL AND VERTICAL DATUM ...................................................................................................... 11 G.2 HORIZONTAL CONTROL ....................................................................................................................... 11

H. SURVEY CHECKS ...................................................................................................................................... 12 H.1 RTK BASE STATION AUSPOS .............................................................................................................. 12 H.2 RTK BENCHMARK POSITION CHECKS...................................................................................................... 12

I. SURVEY RESULTS ..................................................................................................................................... 13 I.1 INITIAL RTK POSITION OF ANTENNAS ..................................................................................................... 13 I.2 AMSA MARINE DGPS SERVICE (PPU) .................................................................................................. 13 I.3 SINGLE FREQUENCY GNSS (PPU) ......................................................................................................... 15 I.4 AMSA DGPS VERSUS L1 GNSS (PPU) COMPARISON .............................................................................. 16 I.5 GPS L1 SBAS (PPU) ......................................................................................................................... 18 I.6 DUAL FREQUENCY GNSS (SEPTENTRIO) ................................................................................................. 19 I.7 SINGLE FREQUENCY GNSS (SEPTENTRIO) ............................................................................................... 21 I.8 SINGLE FREQUENCY GPS (SEPTENTRIO) .................................................................................................. 22

J. WORKPLACE HEALTH AND SAFETY .......................................................................................................... 24 K. DATA DELIVERABLES ............................................................................................................................... 24

K.1 DIGITAL DATASETS ............................................................................................................................. 24 K.2 HARD COPIES .................................................................................................................................... 24

L. SURVEY PERSONNEL ................................................................................................................................ 24 M. APPROVAL .............................................................................................................................................. 24

PHS-20-009-PPA-R001-Rev1 3



LIST OF TABLES Table 1: Abbreviations ............................................................................................................................................ 4 Table 2: Horizontal Comparison of Positioning Methods – PPUs ........................................................................... 7 Table 3: Horizontal Comparison of Positioning Methods – Septentrio Receivers .................................................. 7 Table 4: Vertical Comparison of Positioning Methods – PPUs ................................................................................ 7 Table 5: Vertical Comparison of Positioning Methods – Septentrio Receivers ....................................................... 7 Table 6: Static Test Equipment ............................................................................................................................. 10 Table 7: MGA2020 Parameters ............................................................................................................................. 11 Table 8: RTK Base Station Coordinates ................................................................................................................. 11 Table 9: Survey Benchmark Summary .................................................................................................................. 11 Table 10: AUSPOS RTK Base Station Comparison ................................................................................................. 12 Table 11: Summary of Static RTK Position Checks on Survey Marks .................................................................... 12 Table 12: RTK Positions of Antennas ..................................................................................................................... 13 Table 13: AMSA Marine DGPS Results (Raw) ........................................................................................................ 13 Table 14: AMSA Marine DGPS Results (Reprocessed) .......................................................................................... 14 Table 15: Single Frequency GNSS (PPU) Results ................................................................................................... 15 Table 16: GPS L1 SBAS Results .............................................................................................................................. 18 Table 17: Dual Frequency GNSS Results................................................................................................................ 19 Table 18: Single Frequency GNSS (Septentrio) Results ......................................................................................... 21 Table 19: Single Frequency GPS Results ................................................................................................................ 22 LIST OF FIGURES Figure 1: Standard Deviation Curve ........................................................................................................................ 6 Figure 2: HPL Setup ................................................................................................................................................. 9 Figure 3: Topcon G3-A1 Antenna Setup .................................................................................................................. 9 Figure 4: AMSA DGPS - Horizontal Error (Raw) ..................................................................................................... 13 Figure 5: AMSA DGPS -Vertical Error .................................................................................................................... 14 Figure 6: AMSA DGPS - Horizontal Error (Reprocessed) ....................................................................................... 14 Figure 7: Single Frequency GNSS (PPU) Horizontal Error ...................................................................................... 15 Figure 8: Single Frequency GNSS (PPU) Vertical Error .......................................................................................... 16 Figure 9: AMSA DGPS vs L1 GNSS (PPU) - Easting Error Comparison .................................................................... 16 Figure 10: AMSA DGPS vs L1 GNSS (PPU) - Northing Error Comparison ............................................................... 17 Figure 11: AMSA DGPS vs L1 GNSS (PPU) - Height Error Comparison ................................................................... 17 Figure 12: GPS L1 SBAS - Horizontal Error ............................................................................................................. 18 Figure 13: GPS L1 SBAS - Vertical Error ................................................................................................................. 19 Figure 14: Dual Frequency GNSS Horizontal Error ................................................................................................ 20 Figure 15: Dual Frequency GNSS Vertical Error .................................................................................................... 20 Figure 16: Single Frequency GNSS Horizontal Error .............................................................................................. 21 Figure 17: Single Frequency GNSS Vertical Error .................................................................................................. 22 Figure 18: Single Frequency GPS Horizontal Error ................................................................................................ 23 Figure 19: Single Frequency GPS Vertical Error..................................................................................................... 23 LIST OF APPENDICES APPENDIX A: BASE STATION REPORT APPENDIX B: STATIC BENCHMARK CHECK REPORTS REFERENCES

1. PPA Hydrographic Survey Standards and Deliverables, Pilbara Port Authority, Version 9, 19/06/2020 2. Geocentric Datum of Australia 2020 Technical Manual, ANZLIC Committee on Surveying and Mapping,

Version 1.2, 24 August 2018. 3. Frontier SI Report ‘Pilbara Static Testing 13, 16 May 2020 Preliminary Results, dated 05/06/2020.

4 PHS-20-009-PPA-R001-Rev1



ABBREVIATIONS The following abbreviations may appear in this document:

AHD Australian Height Datum

AHO Australian Hydrographic Office

AHSCP Australasian Hydrographic Surveyor Certification Panel

AMSA Australian Maritime Safety Authority

BM Benchmark

C-O Calculated minus Observed

COG Centre of Gravity

CRP Central Reference Point (Origin of Vessel Coordinate System)

CPHS1 Certified Professional Hydrographic Surveying (Level 1)

CPHS2 Certified Professional Hydrographic Surveying (Level 2)

DGPS Differential Global Positioning System

GAMS GNSS Azimuth Measurement Subsystem

GDA2020 Geocentric Datum of Australia 2020

GNSS Global Navigation Satellite System

GPS Global Positioning System

GRS80 Geodetic Reference System 1980

HAT Highest Astronomical Tide

HPL HarbourPilot Lightweight

IHO International Hydrographic Organisation

IMU Inertial Measurement Unit

ITRF International Terrestrial Reference Frame

kHz Kilohertz

LAT Lowest Astronomical Tide

MGA Map Grid of Australia

MHz Megahertz

NTRIP Network Transport of RTCM via Internet Protocol

PA Ports Australia (formerly AAPMA)

PDOP Position Dilution of Precision

PHS Precision Hydrographic Services

POS MV Position and Orientation Solution – Marine Vessel

PPA Pilbara Ports Authority

PPU Portable Pilot Unit (Consisting of a HPL and TB)

QINSy Quality Integrated Navigation System

QMS Quality Management System

RTK Real Time Kinematic (GPS/GNSS)

SBAS Satellite-Based Augmentation System

SSM State Survey Mark (Also called PSM – Permanent Survey Mark)

TB Toughbook

UTM Universal Transverse Mercator

WA Western Australia

WHS Workplace Health and Safety

WGS84 World Geodetic System of 1984

Table 1: Abbreviations

PHS-20-009-PPA-R001-Rev1 5



A. INTRODUCTION

Precision Hydrographic Services (PHS) in coordination with Frontier SI have been contracted by the Pilbara Ports Authority (PPA) to provide positioning services in support of the SBAS test-bed project, and to test alternative positioning methodologies to the AMSA DGPS service which will be discontinued from July 2020. The project was conducted in four phases:

• Phase One: Static testing of various positioning methods (covered under this report).

• Phase Two: Offshore testing of various SBAS positioning methods (to be reported by Frontier SI).

• Phase Three: Offshore testing of four (4) positioning methods on the Portable Pilot Units (PPU); Raw GNSS, DGPS, SBAS and RTK (covered under this report, PHS-20-009-PPA-R002).

• Phase Four: Positioning of the AMSA DGPS Base Station in Karratha (PHS-20-009-PPA-R003). This report covers the survey methodology and results of the first phase of operations.

B. BACKGROUND

Further details on the SBAS test-bed project, the discontinuation of the AMSA DGPS service and the various positioning methodologies used in this project are provided in the following sections. In addition, an explanation of the statistics calculations used is included.

B.1 SBAS Test-Bed Project

Geoscience Australia is developing an Australian Satellite-Based Augmentation System (SBAS) which augments and corrects GNSS signals to improve the accuracy of positioning data. This system, together with a national network of ground station infrastructure, will improve accuracy to the decimetre level. The new system will be called the Southern Positioning Augmentation Network and is expected to be operational by 2025. This system will include:

• GPS single frequency (L1) SBAS (certified for Australian civil aviation)

• Dual Frequency (L1 and L5) Multi-Constellation (DFMC) SBAS open service

• Open access Precise Point Positioning (PPP) with 10cm positioning accuracy capability Geoscience Australia have partnered with Frontier SI to conduct a trial of this new system, called the SBAS test-bed project. This project has included trials across various industry sectors such as agriculture, aviation, construction, mining and maritime. In support of this project, PPA have agreed to conduct offshore and static trials during the annual hydrographic survey of the Port Hedland, Dampier, and Ashburton ports.

B.2 Discontinuation of AMSA DGPS

The PPA’s contracted marine pilots navigate the bulk carriers from the Port of Port Hedland Inner Harbour to the end of the 42km channel with the aid of Portable Pilot Units (PPU) that operate utilising the GPS network augmented by a DGPS correction signal produced by a station operated by the Australian Marine Safety Authority (AMSA) from Karratha, some 200km southwest of Port Hedland. AMSA’s DGPS service was introduced in the late 1990s to reduce up to 200 metres of error from Selective Availability, down to approximately 10 metres. According to the AMSA website, “the DGPS infrastructure has not been upgraded and should not be relied upon to provide any better accuracy than approximately 10 metres. It is now old technology, is limited by range, and due to its age is becoming more unreliable”. AMSA announced in December 2019 that the DGPS signals their stations provide around Australia will be discontinued on 1 July 2020. The reason AMSA have provided for the discontinuation is due to the increased accuracy of raw GPS, and the introduction of other global positioning constellations including GLONASS, GALILEO and BEIDOU. The PPA has negotiated that AMSA will continue the operation of its Karratha DGPS service to support the operational needs of the Port of Port Hedland however an alternative positioning method will need to be used for the marine pilot PPUs once the Karratha DGPS service is discontinued. The below positioning methods have been tested as part of this project, and compared against the current AMSA DGPS service:

• SBAS

6 PHS-20-009-PPA-R001-Rev1



• Single frequency GNSS

• RTK

B.3 Single/ Dual Frequency and GNSS/GPS Explained

GNSS stands for Global Navigation Satellite System and is an umbrella term that encompasses all global satellite positioning systems. The Global Positioning System (GPS) is one component of the Global Navigation Satellite System. Specifically, it refers to a constellation of satellites developed by the United States Department of Defense (DoD). Other GNSS constellations include GLONASS (Russia), GALILEO (EU), and Beidou (China). There are three main different bands of frequencies used in GNSS. Single frequency receivers use only one of these bands (e.g. the L1 band in GPS), while dual frequency receivers use two bands (e.g. for GPS this is either he L1 and L2 bands, or the L1 and L5 band). In general, dual frequency GNSS receivers will provide a faster, more accurate, and more reliable solution than single frequency equipment, as the effects of ionospheric errors and the ambiguity resolution time are reduced.

B.4 Statistical Analysis

Throughout this report the mean has been reported to describe how the measurements compare to the “true” value and standard deviation describes the distribution (spread) of the measurements. A lower standard deviation indicates that the values are close together (more precise), and a higher standard deviation indicates that the values are more spread out (less precise). The confidence level is the probability that the true value of a measurement will lie within a specified uncertainty from the measured value (mean). One Sigma (1σ) is the 68% confidence level and indicates that 68% of the sample data lies within the specified value, also known as the standard deviation. Data has also been expressed at the 95% confidence level (2σ) indicating that 95% of sample data lies within the specified value. The 2 sigma value is calculated by multiplying the 1 sigma value by 1.96 for one dimensional measurements (height) and 2.45 for two dimensional measurements (position E,N) Figure 1 shows a graphical representation of the sigma values assuming a normal distribution of samples about the mean value.

Figure 1: Standard Deviation Curve

PHS-20-009-PPA-R001-Rev1 7



C. EXECUTIVE SUMMARY

The following presents a summary of the horizontal positioning accuracy and precision of the various positioning methods used in comparison to the initial RTK observed position:

AMSA DGPS (PPU) Raw

AMSA DGPS (PPU)

Reprocessed

Single Frequency

GNSS (PPU) SBAS (PPU)

Mean Horizontal Difference (m) 1.536 0.390 0.630 0.314

Standard Deviation (1σ at 68% CI) 0.306 0.222 0.338 0.172

95% CI (2.45 x σ) 0.750 0.544 0.828 0.421

Table 2: Horizontal Comparison of Positioning Methods – PPUs

Dual Frequency GNSS (Septentrio)

Single Frequency GNSS (Septentrio)

Single Frequency GPS (Septentrio)

Mean Horizontal Difference (m) 0.619 0.633 0.711

Standard Deviation (1σ at 68% CI) 0.361 0.298 0.346

95% CI (2.45 x σ) 0.884 0.730 0.848

Table 3: Horizontal Comparison of Positioning Methods – Septentrio Receivers The AMSA DGPS corrected position was the most inaccurate with a mean horizontal difference of 1.536m. This is due to an issue with the DGPS base station position, which was established in May 2000 on ITRF97. The location of this base has not been updated since installation and therefore has not taken into account plate tectonics which have pushed the entire continent north-east. Following the results of this static test, the Karratha DGPS base station was re-positioned under phase 4 of this project (report no. PHS-20-009-PPA-R003) and a ~1.7m horizontal position difference was observed. The AMSA DGPS PPU data was reprocessed using the Karratha DGPS base station positional difference and the accuracy increased, with a mean horizontal difference of 0.390m versus 1.536m. As expected, the SBAS corrected position proved to be the most accurate with a mean horizontal difference of 0.314m, and the most precise with a standard deviation of 0.172m. The reprocessed AMSA DGPS position closely followed the SBAS in terms of accuracy and precision. All variations of GNSS positioning were comparable in terms of accuracy (mean horizontal difference from 0.619m to 0.633) and precision (0.298m to 0.361m). The dual frequency GNSS was slightly more accurate than the single frequency GNSS (mean horizontal difference of 0.619m versus 0.633m), however for unknown reasons the precision was larger at 0.361m versus 0.298m. The single frequency GPS was less accurate than the single or dual frequency GNSS positioning, due to the decreased number of satellites that would have been used. The following presents a comparison of the vertical accuracy and precision of the various positioning methods:

AMSA DGPS (PPU)

Single frequency GNSS (PPU)

SBAS (PPU)

Mean Vertical Difference (m) -0.352 -0.338 -0.402


95% CI (1.96 x σ) 1.760 2.442 1.258

Table 4: Vertical Comparison of Positioning Methods – PPUs

Dual Frequency GNSS (Septentrio)

Single Frequency GNSS (Septentrio)

Single Frequency GPS (Septentrio)

Mean Vertical Difference (m) 0.037 -1.995 -2.049


95% CI (1.96 x σ) 2.256 1.823 2.229

Table 5: Vertical Comparison of Positioning Methods – Septentrio Receivers As expected, the SBAS corrected height proved to be the most precise with a standard deviation of 0.642m, followed next by the AMSA DGPS with a standard deviation of 0.898m. All other GNSS/GPS heights were less precise with standard deviations ranging from 0.930m to 1.246m.

8 PHS-20-009-PPA-R001-Rev1



D. CONCLUSION

The following summarises the results of the static testing:

• The AMSA DGPS position was the most inaccurate with a mean horizontal difference of 1.536m. This is due to the base station coordinates not being updated since May 2000, and therefore have not taken into account plate tectonics which have pushed the entire continent north-east.

• Following the results of this static test, the Karratha DGPS base station was re-positioned and a ~1.7m horizontal position difference was observed. The AMSA DGPS PPU data was reprocessed using the Karratha DGPS base station positional difference and the accuracy increased, with a mean horizontal difference of 0.390m versus 1.536m.

• SBAS was the most accurate and precise positioning method of those tested, followed closely by the reprocessed AMSA DGPS data.

• All variations of GNSS/GPS had an accuracy in the range of 0.619m-0.711m, with a standard deviation of 0.298m-0.361m.

• The single frequency GPS was less accurate than the single or dual frequency GNSS positioning, due to the decreased number of satellites that would have been used.

• For unknown reasons the single frequency GNSS performed better than the dual frequency GNSS.

• Height precision is poor for all systems with a standard deviation ranging from 0.642m to 1.246m.

PHS-20-009-PPA-R001-Rev1 9



E. STATIC TEST METHODOLOGY

The following method was used to acquire data for the static test:

• PHS has a permanent office at the Jetwave Marine yard in Port Hedland. Five GNSS antennas were secured to the top of a container, and the cables run into the PHS office.

• The five GNSS antennas and receivers were setup to log the following positioning data: o AMSA Marine DGPS service (PPU) o GPS-L1 SBAS (PPU) o Single frequency GNSS (AsteRx-U receiver and Topcon G3-A1 Antenna) o Dual frequency GNSS (AsteRx-SB receiver and Topcon G3-A1 Antenna) o Single frequency GPS (AsteRx-U receiver and Topcon G3-A1 Antenna)

• The initial positions of the antennas were observed using 15-minute RTK observations with corrections from the Port Hedland Tower RTK base station.

• The antennas/receivers were mobilised and commenced logging on 12 May 2020 and logged to obtain three full UTC days of data. During this period, two changes occurred:

o On evening of 12 May the Hed20 Toughbook experienced a fault and crashed overnight. The equipment configuration was amended so that both HPLs were being logged by the Hed21 Toughbook, and the logging period was restarted at 07:10hrs (AWST) on 13 May.

o After the first two days of logging and preliminary analysis by Frontier SI, the SBAS configured HPL was reconfigured to log standalone single frequency GNSS.

• Data logging was stopped at 08:15hrs (AWST) on 16 May, and the Septentrio AsteRx-SB receiver was demobilised to be used for the offshore SBAS test phase of the project.

• The RTK positions were used as a baseline, and all GPS/GNSS/SBAS/DGPS positions were compared against RTK.

Figure 2: HPL Setup

Figure 3: Topcon G3-A1 Antenna Setup

10 PHS-20-009-PPA-R001-Rev1



F. EQUIPMENT

F.1 Static Test Equipment

The following equipment was used for the static test:

Static Test Equipment

No. Provided by

Description Comment

1 PPA Navicom HarbourPilot Lightweight (Hed20)

HPL configured for SBAS (L1 GPS) Later configured for dual frequency GNSS

2 PPA Navicom HarbourPilot Lightweight and Qastor enabled Toughbook (both Hed21)

HPL configured for the AMSA Marine DGPS service

3 Frontier SI

Septentrio AsteRx-SB receiver and Topcon G3-A1 Antenna

Configured for single frequency GNSS

4 Frontier SI

Septentrio AsteRx-U receiver and Topcon G3-A1 Antenna

Configured for dual frequency GNSS

5 Frontier SI

Septentrio AsteRx-U receiver and Topcon G3-A1 Antenna

Configured for dual frequency GPS

6 PHS Trimble R8 RTK Rover Used for the initial accurate positioning of the antennas

Table 6: Static Test Equipment

F.2 RTK Base Station Equipment

GNSS corrections for the RTK rover were provided from the PPA Tower base station. The following is a list of components at the RTK base station at the PPA Tower.

• 1 x Trimble SPS 855 GNSS Receiver

• 1 x Zephyr 2 Geodetic Antenna

• 1 x ADL Vantage Broadcasting Radio

F.3 Software

Details of the software in use during the survey are as follows:

• QPS Qastor

PHS-20-009-PPA-R001-Rev1 11



G. DATUM AND CONTROL

G.1 Horizontal and Vertical Datum

The horizontal and vertical datum used throughout the project was the Geocentric Datum of Australia 2020 (GDA2020), using Map Grid of Australia (MGA2020), Zone 50 for grid coordinates. See Table 7 for the MGA94 parameters5.

Parameter Value

Datum GDA2020

Ellipsoid GRS 80

Semi Major Axis 6378137.0 m

Inverse Flattening (1/f) 298.257222101

Projection Universal Transverse Mercator

Zone 50 (South)

Latitude of Origin 0° N

Longitude of Origin 117° 00’E

False Easting (m) 500,000.00

False Northing (m) 10,000,000.00

Central Meridian Scale Factor 0.9996

Table 7: MGA2020 Parameters With the exception of the RTK baseline, all raw positioning data was collected in WGS84/ITRF2014. The transformation parameters to transform from ITRF2014 to GDA2020 are provided below:

𝒕𝒙,�̇�𝒙 𝒕𝒚,�̇�𝒚 𝒕𝒛,�̇�𝒛 𝒔𝒄,�̇�𝒄 𝒓𝒙,�̇�𝒙 𝒓𝒚,�̇�𝒚 𝒓𝒛,�̇�𝒛

0.00 0.00 0.00 0.00 0.00 0.00 0.00

Uncertainty 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Rates 0.00 0.00 0.00 0.00 0.00150379 0.00118346 0.00120716

Uncertainty 0.00 0.00 0.00 0.00 0.00000417 0.00000401 0.00000370

G.2 Horizontal Control

A single GNSS base station was used throughout the project to supply RTK corrections. The base station had been previously established by PHS and remains a permanent installation on the PPA network.

Parameter PHE Tower

Latitude (GDA94) 20°18'52.21394" S

Longitude (GDA94) 118°34'34.58621" E

Height (GDA94) 48.916 m

Source Long term averaging of Final Orbit AUSPOS Data (over 1100 hours of logging).

Table 8: RTK Base Station Coordinates Two state survey benchmarks (SSM) were used to validate the position of the GNSS base station and to confirm the correct operation of the GNSS RTK Rover used for establishing the antenna positions. The details of the SSMs are provided below in Table 9.

SSM Latitude (GDA94) Longitude (GDA94)

Easting (MGA50)

(m)

Northing (MGA50) (m)

Height (AHD)

(m)

Source

PORT HEDLAND

98 S 20° 18' 31.65849" E 118° 36' 08.58315" 667305.154 7753534.805 8.493 Landgate

PORT HEDLAND

99A S 20° 18' 33.25808" E 118° 35' 17.27052" 665816.177 7753500.008 15.113 Landgate

Table 9: Survey Benchmark Summary

12 PHS-20-009-PPA-R001-Rev1



H. SURVEY CHECKS

H.1 RTK Base Station AUSPOS

The position of the RTK base station was checked by processing a 24-hour RINEX base logging using the AUSPOS processing service, final orbit solution. The results are presented in Table 10 below.

Observation Easting (m) (MGA2020 Zone 50)

Northing (m) (MGA2020 Zone 50)

Ellipsoid Height (m) GDA2020

Established RTK Base Position 664572.411 7752929.007 48.916

Observed AUSPOS Final Orbit Position 664572.413 7752929.003 48.913

Difference 0.002 -0.004 -0.003

Table 10: AUSPOS RTK Base Station Comparison The AUSPOS position compares well against the known base station position, confirming that no movement has occurred since the base position was established.

H.2 RTK Benchmark Position Checks

Position and height checks were conducted using the Trimble R8 RTK rover on two benchmarks (outlined in Table 9). These checks were conducted to assess the reliability of the GNSS base station and confirm the correct operation of the Trimble GNSS rover. Each position is computed from a set of one second observations over a five-minute period. See Table 11 below for a summary of the benchmark position checks.

Benchmark Easting

Difference (m) Northing

Difference (m) AHD Elevation Difference (m)

16/05/2020 PH98 -0.027 -0.028 0.031

PH99A -0.019 -0.049 0.033

Table 11: Summary of Static RTK Position Checks on Survey Marks A higher than expected northing difference was observed in the PH99A SSM, however this difference is within the expected uncertainty tolerances of the equipment. The remaining observations compare well against the known benchmark positions, and confirm the base station is coordinated and configured appropriately, and the rover is operating to expectations. Subsequent checks on the PH99A benchmark during the annual pre-dredge survey have not had the same difference, so this appears to be a random error. Refer to Appendix B for further details.

PHS-20-009-PPA-R001-Rev1 13



I. SURVEY RESULTS

I.1 Initial RTK Position of Antennas

The initial position of the five antennas were observed using 15-minute RTK observations with corrections from the Port Hedland RTK base station. These positions are presented in Table 12 and will be the baseline upon which all other observations are compared.

Antenna Easting(m)

(MGA2020 Zone 50) Northing(m)

(MGA2020 Zone 50) Height(m) to bottom of antenna

(GDA2020 Ellipsoid)

Pos1-GPS 665093.557 7753273.888 4.755

Pos2-GNSS L1 665093.575 7753274.285 4.753

Pos3-All Freq All GNSS 665093.471 7753274.898 4.743

Pos4-Hed21 665093.250 7753274.449 4.684

Pos5-Hed20 665092.982 7753274.416 4.689

Table 12: RTK Positions of Antennas The Trimble R8 RTK uncertainty as stated in the manufacturers specifications is 2cm + 2ppm, which equals 2.001cm. The actual uncertainty is dependent on many factors; however we estimate the total uncertainty to be no greater than 5cm.

I.2 AMSA Marine DGPS Service (PPU)

The Hed21 Navicom HarbourPilot Lightweight system was configured to receive AMSA Marine DGPS corrected positions. A comparison of the antenna position and height to the RTK are provided in Table 13, Figure 4 and Figure 5.

Observation East

(MGA2020 Zone 50) North

(MGA2020 Zone 50) Height

GDA2020

RTK (GDA2020) 665093.250 7753274.449 4.684

Average AMSA DGPS (GDA2020) 665092.295 7753273.273 5.036

Mean Difference (m) 0.955 1.176 -0.352

Maximum Difference (m) 0.048 0.417 3.697

Minimum Difference (m) -1.624 -2.260 -3.501

Range 1.672 2.677 7.198

Table 13: AMSA Marine DGPS Results (Raw)

Figure 4: AMSA DGPS - Horizontal Error (Raw)

Mean 0.955mE, 1.176mN Std Dev: 0.306m

14 PHS-20-009-PPA-R001-Rev1



Figure 5: AMSA DGPS -Vertical Error

There is a clear mean centre offset with all observed easting and northing points sitting south-west of the RTK position. As mentioned in Section C. this is due to an error in the base station position which has not been updated over time to include the effects of plate tectonics which have pushed the continent north-east. The data has been reprocessed using the revised Karratha DGPS base station positional difference and the results are presented in Table 14 and Figure 6.

Observation East

(MGA2020 Zone 50) North

(MGA2020 Zone 50)

RTK (GDA2020) 665093.250 7753274.449

Average AMSA DGPS (GDA2020) Reprocessed 665093.268 7753274.661

Mean Difference (m) -0.018 -0.212

Maximum Difference (m) 1.021 1.805

Minimum Difference (m) -0.651 -0.872

Range 1.672 2.677

Table 14: AMSA Marine DGPS Results (Reprocessed)

Figure 6: AMSA DGPS - Horizontal Error (Reprocessed)

Mean -0.018mE, -0.212mN Std Dev: 0.222m

Mean -0.352m, Std Dev: 0.898m

PHS-20-009-PPA-R001-Rev1 15



After reprocessing, the horizontal error is significantly improved. Navicom HPL specifications state the expected positional accuracy when applying DGPS corrections should be approximately 0.3m, the observed static position is within this expected positioning accuracy with a difference of -0.018mE and -0.212mN.

I.3 Single Frequency GNSS (PPU)

After logging SBAS (Section 0), the Hed21 Navicom HarbourPilot Lightweight system was configured to receive raw single frequency GNSS positions. A comparison of the antenna positions and heights to the baseline RTK positions are provided in Table 15, Figure 7 and Figure 8.

Observation East

(MGA2020 Zone 50)

North (MGA2020 Zone 50)

Height GDA2020

RTK (GDA2020) 665092.982 7753274.416 4.689

Average Single Frequency GNSS (GDA2020)

665092.694 7753274.259 4.351

Mean Difference (m) -0.301 -0.178 -0.338

Maximum Difference (m) 0.831 1.267 2.915

Minimum Difference (m) -1.291 -1.804 -4.793

Range 2.122 3.071 7.708

Table 15: Single Frequency GNSS (PPU) Results

Figure 7: Single Frequency GNSS (PPU) Horizontal Error

Navicom HPL specifications state the expected positional accuracy of the uncorrected single frequency GNSS is 1.2m. The HPL performed much better than the specified accuracy, with an average mean difference of -0.301m east, and -0.178m north.


16 PHS-20-009-PPA-R001-Rev1



Figure 8: Single Frequency GNSS (PPU) Vertical Error

I.4 AMSA DGPS versus L1 GNSS (PPU) Comparison

A side by side comparison of the AMSA DGPS (PPU) and L1 GNSS (PPU) easting error, northing error, and vertical error is presented below in Figure 9 to Figure 11.

Figure 9: AMSA DGPS vs L1 GNSS (PPU) - Easting Error Comparison


PHS-20-009-PPA-R001-Rev1 17



Figure 10: AMSA DGPS vs L1 GNSS (PPU) - Northing Error Comparison

As expected, the spread of the AMSA DGPS horizontal data is less than the L1 GNSS data, with the L1 GNSS data having larger spikes in comparison. However as previously stated the AMSA DGPS position is offset from the correct position.

Figure 11: AMSA DGPS vs L1 GNSS (PPU) - Height Error Comparison

While height accuracy and precision is not the main focus of the project the AMSA DGPS height is marginally more stable than the L1 GNSS height.

18 PHS-20-009-PPA-R001-Rev1



I.5 GPS L1 SBAS (PPU)

The Hed21 Navicom HarbourPilot Lightweight system was configured to receive SBAS corrected positions. A comparison of the SBAS (GPS L1) antenna position and height to the baseline RTK positions are provided in Table 16, Figure 12 and Figure 13.

Observation East

(MGA2020 Zone 50)


Height GDA2020

RTK (GDA2020) 665092.982 7753274.416 4.689

Average GPS L1 SBAS (GDA2020) 665092.842 7753274.328 4.286


Maximum difference (m) 0.826 0.494 3.161

Minimum difference (m) -0.761 -0.832 -2.409

Range 1.587 1.326 5.570

Table 16: GPS L1 SBAS Results

Figure 12: GPS L1 SBAS - Horizontal Error

Navicom HPL specifications state that the expected positional accuracy of the SBAS corrections is 0.3m. The HPL performed better than the specified accuracy, with an average mean difference of -0.139m east, and -0.088m north. As expected, the SBAS observed the most accurate and precise position and height of all the positioning methods.


PHS-20-009-PPA-R001-Rev1 19



Figure 13: GPS L1 SBAS - Vertical Error

I.6 Dual Frequency GNSS (Septentrio)

A Septentrio AsteRx-SB receiver was configured to receive dual frequency GNSS positions. A comparison of the antenna position and height to the baseline RTK positions are provided in Table 17, Figure 14 and Figure 15.

Observation East

(MGA2020 Zone 50)


Height GDA2020

RTK (GDA2020) 665093.471 7753274.898 4.776

Average Dual Freq GNSS (GDA2020) 665093.464 7753274.864 4.813

Mean Difference (m) -0.007 0.619 0.037


Minimum difference (m) -3.555 0.001 -2.798

Range 5.471 3.607 6.047

Table 17: Dual Frequency GNSS Results


20 PHS-20-009-PPA-R001-Rev1



Figure 14: Dual Frequency GNSS Horizontal Error

Of all the positioning methods, the dual frequency GNSS had the largest positioning range at 5.471m between the minimum and maximum easting error. This outlier is evident in the above scatter plot. The cause of this outlier is unknown. As per the Septentrio AsteRx-U specifications, the expected positional accuracy of dual frequency GNSS is 1.2m. The receiver performed better than the specifications, with an average easting error of -0.007m and average northing error of 0.619m.

Figure 15: Dual Frequency GNSS Vertical Error

Mean -0.007mE, 0.619mN Std Dev: 0.361m

Mean 0.037m, Std Dev: 1.151m

PHS-20-009-PPA-R001-Rev1 21



I.7 Single Frequency GNSS (Septentrio)

A Septentrio AsteRx-U receiver was configured to receive single frequency GNSS positions. A comparison of the antenna position and height to the baseline RTK positions are provided in Table 18, Figure 16 and Figure 17.

Observation East

(MGA2020 Zone 50)


Height GDA2020

RTK (GDA2020) 665093.575 7753274.285 4.786

Average Single Frequency GNSS (GDA2020)

665093.926 7753273.892 2.791




Range 1.504 2.045 4.810

Table 18: Single Frequency GNSS (Septentrio) Results

Figure 16: Single Frequency GNSS Horizontal Error

In theory, the dual frequency GNSS should have performed better than single frequency, however, as is evident in the above scatterplot, the spread of the data is tighter in comparison to the dual frequency GNSS data.

Mean -0.309mE, -0.393mN

Std Dev: 0.298m

22 PHS-20-009-PPA-R001-Rev1



Figure 17: Single Frequency GNSS Vertical Error

I.8 Single Frequency GPS (Septentrio)

A Septentrio AsteRx-U receiver was configured to receive single frequency GPS positions. A comparison of the SBAS (GPS L1) antenna position and height to the baseline RTK positions are provided in Table 19, Figure 18, and Figure 19.

Observation East

(MGA2020 Zone 50)


Height GDA2020

RTK (GDA2020) 665093.557 7753273.888 4.788

Average Single Freq GPS (GDA2020) 665093.287 7753273.431 2.739




Range 2.607 3.178 5.754

Table 19: Single Frequency GPS Results


PHS-20-009-PPA-R001-Rev1 23



Figure 18: Single Frequency GPS Horizontal Error

The Septentrio specifications do not specify the different uncertainties between GNSS and standalone GPS, however it would be expected that due to the lower number of satellites the accuracy would be larger than the 1.2m GNSS stated accuracy. The single frequency GPS performed better than expected, with an average easting error of -0.269m and average northing error of -0.457m.

Figure 19: Single Frequency GPS Vertical Error



24 PHS-20-009-PPA-R001-Rev1



J. WORKPLACE HEALTH AND SAFETY

Prior to arriving on site, a kick off meeting was conducted to discuss the scope of work and highlight risks for the project. A Risk Assessment was also prepared prior to commencing the works to highlight standard risks in the day to day survey operations. This project was performed with no incidents or near misses.

K. DATA DELIVERABLES

All processed data is being delivered in the following formats:

K.1 Digital Datasets

• Survey Report(.pdf)

• All raw positioning data.

K.2 Hard Copies

• Survey Report.

L. SURVEY PERSONNEL

The following PHS personnel were involved in this project:

• Jennifer Brindle Project Manager (AHSCP Certified Level 1, Supervising Surveyor)

M. APPROVAL

Report, deliverables and data approved by:

Jennifer Brindle Certified Professional Hydrographic Surveyor Level 1 Senior Hydrographic Surveyor – Precision Hydrographic Services Date: 21/09/2020

PHS-20-009-PPA-R001-Rev1



APPENDIX A: BASE STATION REPORT

BASE STATION REPORT

CONTRACT NUMBER:

CLIENT:

PROJECT NAME:

PERSONNEL:

GRID:

LATITUDE (DMS): EAST: LATITUDE (DMS):

LONGITUDE (DMS): NORTH: LONGITUDE (DMS):

ELLIPSOID HEIGHT: ELLIPSOID HEIGHT:

Uncertainty (95% conf.): East: North: 0.001m

User:

LAN IP Address: 192.168.3.55

NTRIP Caster: User:

Port: => CMRx

Port: => CMR

Port: => RTCM_V3

Radio Frequency: Link rate:

Correction format:

Location Sketch

POSITION COORDINATES

MGA2020 Z50GDA2020

20°18'52.21394" S

118°34'34.58621" E

48.916 m

20°18'52.26286" S

118°34'34.55138" E

49.005 mAHD HEIGHT: 50.428 m

PHS-20-009-PPA

Pilbara Ports Authority

Provision of RTK / SBAS Positioning Services

Jennifer Brindle CPHS1

SETUP INFORMATION

LOCATION: Control Tower, Port Hedland

MOBILISED ON: Aug-19

Base station picture - Trimble SPS851

- Pacific Crest ADL Vantage UHF Radio

NAME / ID: PHE_TWR

POWER SOURCE: 240V AC from tower

EQUIPMENT USED:

Antenna Type: Trimble Zephyr Geodetic 2

Antenna Height: Antenna Reference Point at 0.000m

DATUM:

METHODOLOGY:

7752929.007 m

DATUM: GDA94

0.005m

Offset ARP to APC: 0.085 m

664572.411 m

Location map + 5-10-15Km radius

10002

10003

Protocol:463.5 MHz

Long term averaging of AUSPOS Data (over 1100 hours worth of loggings) with dates ranging from

October/November 2019 and February/March 2020. GDA2020 Position established May 2020.

0.001m Height:

TT48004800 Baud

RTCM_V3

5163#k0ala

10001

49.255.1.187 admin PW:

COMMUNICATION / CORRECTIONS Tx

WebGUI Access: citrix.pilbaraports.com.au PW: 5163#k0alaadmin

OPS-FOR-SS1-V1.0

Issued: April 2018 Page 1 of 2

http://phs-rtkbasex.dyndns.org/






BASE STATION REPORT

FORMAT *.T02

SSM

GNSS BASE STATION SETTINGS

DATA LOGGING

DATA LOGGING ENABLED Mode IntervalContinuous 5 seconds

Trimble SPS585

Validated

OBSERVED

PH98 EASTING

PHS Rep: Jennifer Brindle CPHS1

0.034

DATA TRANSFER METHOD PHS staff to download via Citrix as required.

Signature:

Client Rep: Geordie Hall

ADDITIONAL INFORMATION:

The base station has recently be configured for GDA2020.

AUSPOS POSITION CHECKS

Differences: Easting: -0.002 m, Northing 0.004 m, Height: 0.003 m

7753534.829

8.493

8.459

BASE STATION CORRECTION CHECKS (checked on 12/12/19)

THEORETICAL

DIFFERENCE -0.030 -0.024

SOURCE / ROVER

Landgate

667305.184

7753534.805667305.154

NORTHING HEIGHT

OPS-FOR-SS1-V1.0

Issued: April 2018 Page 2 of 2

PHS-20-009-PPA-R001-Rev1



APPENDIX B: STATIC BENCHMARK CHECK REPORTS

BENCHMARK POSITION CHECKo

DATE:

Datum Latitude Longitude Height Frequency

GDA2020 20°18'52.21394"S 118°34'34.58621"E 48.916 463.5MHz

Base Station position last checked/updated on: dd/mm/yyyy Note:

From N/A 7 Parameters Transformation Dx (m) Rx (")

To Dy (m) Ry (")

Epoch Source: Geoscience Australia Dz (m) Rz (")

Antenna Height: 2.0 metres NTRIP

GDA94 AHD

Latitude Longitude Elevation Height X Y Z

Source: 8.493

Rover: 8.462 0.006 0.005 0.012

Difference 0.031

GDA94 AHD


Source: 15.113

Rover: 15.080 0.006 0.005 0.010

Difference 0.033

GDA94 AHD


Source:

Rover:

Difference

AusGeoid2020Geoid Model used: Corrections Rx:

GDA94

Observed data 665816.196 7753500.057

-0.019 -0.049

SSM IDGDA94 MGA2020 Zone 50 Position Uncertainty (95%)

Eastings Northings

Position Uncertainty (95%)

Eastings Northings

R8

TO BE PERFORMED PRIOR TO THE START OF SURVEYING OPERATIONS AND ON A REGULAR BASIS

Pilbara Ports Authority16/05/2020 CLIENT:

Port Hedland

PROJECT NAME:

GDA94

Northings

Scale Factor (ppm)

PH98MGA2020 Zone 50

Eastings

3 minRover Observations Averaging:

BASE STATION INFORMATION

DATUM TRANSFORMATION PARAMETERS (if applicable)

Base Station ID Location

PHE_Twr

CONTRACT NUMBER: PHS-20-009-PPA

POSITION CHECK ON SURVEY BENCHMARKS

Tower

Antenna Type Corrections

Zephyr Geodetic 2

SURVEY PERSONNEL:

Provision of SBAS/RTK Positioning Services

Jennifer Brindle CPHS1 LOCATION:

CMR+ 49.255.1.187:10002

NTRIP IP address:port

Benchmark data Landgate 7753534.805

7753534.833

667305.154

667305.181

MGA2020 Zone 50

Observed data

Benchmark data 665816.177 7753500.008

-0.027 -0.028

Benchmark data

Observed data

SSM ID

SSM ID PH99A

Position Uncertainty (95%)

OPS-FOR-SC1-V2.0

Issued: Oct 2018 Any printed or digital copy of this document shall be deemed to be an “Uncontrolled” documentPage 1 of 2

Review: October 2020

BENCHMARK POSITION CHECKo

Jennifer Brindle

COMMENTS:

A higher than expected northing difference was observed on the SSM99A.

0

Signature:

Client rep:PHS rep: Geordie Hall

PH99APH98

7753534.800

7753534.805

7753534.810

7753534.815

7753534.820

7753534.825

7753534.830

7753534.835

7753534.840

7753534.845

667305.150667305.160667305.170667305.180667305.190667305.200

Eastings / Northings

R8 Landgate

8.440

8.450

8.460

8.470

8.480

8.490

8.500AHD Height

7753500.000

7753500.010

7753500.020

7753500.030

7753500.040

7753500.050

7753500.060

7753500.070

665816.170665816.180665816.190665816.200


0.000

0.200

0.400

0.600

0.800

1.000

1.200

0.000 0.200 0.400 0.600 0.800 1.000 1.200


15.060

15.070

15.080

15.090

15.100

15.110

15.120AHD Height

0.000

0.200

0.400

0.600

0.800

1.000AHD Height

OPS-FOR-SC1-V2.0

Issued: Oct 2018 Any printed or digital copy of this document shall be deemed to be an “Uncontrolled” documentPage 2 of 2

Review: October 2020

Provision of SBAS/RTK/GNSS Static Positioning Services ...

Documents

Transcript of Provision of SBAS/RTK/GNSS Static Positioning Services ...