Sydney Satellites Paul Harcombe Chief Surveyor and Director, LPCU
Who is LPI?
• Land Titling
• Valuations
• Surveying & Mapping
Responsible for maintaining the NSW State Survey Infrastructure
• Where am I?
• Where is it?
• Which direction?
• How far?
Who connects to Survey Infrastructure?
• Past • Now
(GNSS) Positioning Infrastructure
Limitations of GNSS Limited or no service in:
• Urban/Natural Canyons
• Vegetated Areas
• Indoors
• Underground
• Underwater
• High levels of radio frequency interference
Susceptible to:
• Interference
• Intentional Jamming
• Spoofing
• Space weather events
• Military motives
• Non-Australian decision makers
Dependence and Vulnerability • Global Navigation Space Systems: reliance and
vulnerabilities (The Royal Academy of Engineering) • Mid-term review of European satellite radio navigation
programmes (European Commission) • NSTAC Report to the President on Commercial
Communications Reliance on the Global Positioning System (National Security Telecommunications Advisory Committee)
• Australian Strategic Plan for GNSS (Australian Spatial Consortium
• ...
Alternatives Revert back to old methods? • Norm for most NSW surveyors
Adopt new technology, but it would need to:
• Work in real-time
• Achieve cm level accuracy in national coordinate system
• Integrate with other sensors and systems
Sydney Satellites • World first test of the performance of Locata vs GNSS in
a maritime environment. Collaborative partners:
• Observed by Australian Hydrographic Service (RAN)
What is Locata? Ground based positioning system consisting of:
• Four or more ‘LocataLites’ (shown in picture) which synchronise with each other using TimeLoc
• LocataLites can be set up on existing control or surveyed in
• Locata rover(s) roaming within bounds of LocataLites
Objectives
Quickly establish a temporary Locata network in a harbour/maritime scenario
Determine the position for a vessel moving within the network using Locata technology
Evaluate the performance of Locata compared to existing positioning techniques (GNSS)
Preparation Work In the lead up to the final test day:
• Multiple reconnaissance trips
• Stakeholder meetings
• UNSW practice day
• Signal test day
• UNSW/Locata training day
• Preliminary positioning test day
Example Test Run
Fort Denison CORS
Set-Up on Sydney Ports Corp. Vessel
Locata Receiver
Temporary Antenna Mount
Antennas
SPC GPS SPC GPS
Test GPS Test GPS
Locata Helix Locata 5/8 Wave
Preliminary Results • Analysis of three runs of Farm Cove
• Approximately 12 minutes of data
• LocataLites ‘in view’ ranges from 4 up to 7 during this particular session
• Data collected at 10Hz (both GPS and Locata)
• Compared to GPS RTK solution after offsets taken into account
2D RMS Error (95%)
Horizontal: 4.4 cm
Comparison to high-precision GPS.
Outcomes Quickly establish a temporary Locata
network in a harbour/maritime scenario
Determine the position for a vessel moving within the network using Locata technology
Evaluate the performance of Locata compared to existing positioning techniques (GNSS)
Next phase of testing • Emergency Services Applications
– Urban environments/Indoors
– Barangaroo development or Australian Technology Park possible locations
• Port Logistics
• National Positioning Infrastructure – Where does it fit?
– Enable navigation through virtual world