What are the issues with Multi-GNSS Enabling the National Positioning Infrastructure? John Dawson and Gary Johnston Earth Monitoring and Hazards Group

Quick Recap on Australia’s NPI Plan  A national positioning capability is a key component of Australia’s future economy  Hence Australian Federal Government interest

Quick Recap on Australia’s NPI Plan  Australian government developed a National Positioning Infrastructure (NPI) Plan  Led by Geoscience Australia  Whole-of-Government approach  Recognises the importance of multi-GNSS  Mitigates total reliance on GPS  Anticipates improved positioning capabilities through access to more GNSS signals/satellites

Building Australia’s NPI Improved Governance Ground Infrastructure Development GNSS Analysis Capability  The three ‘easy’ steps towards building an NPI  National coordination is hard  But the move to multi-GNSS introduces additional challenges

History of Multi-GNSS at Geoscience Australia  Contributing GPS data to the IGS since its inception 1993  Since 2000, Contributing GLONASS data to the IGS -- International GLONASS Experiment  Tracking Galilieo Giove since 2010 (Stromlo, Canberra) and 2011 (Davis, Antarctica) and contribution to the COoperative Network for GIOVE Observation (CONGO)

History of Multi-GNSS at Geoscience Australia  Since 2010, progressively upgrading the national (ARGN+AuScope) network to GPS+GLONASS+others  Since 2010, hosting a QZSS master control station at Mount Stromlo  In 2013, regional multi-GNSS data sharing agreement with JAXA QZSS Monitor Station – Mount Stromlo Canberra

History of Multi-GNSS at Geoscience Australia  Deploying 10 Multi-GNSS Septentrio receivers in  CRCSI, Curtin University ionospheric scintillation experiments  Ongoing laser tracking of retro-reflector equipped GPS, GLONASS, COMPASS, Galileo, QZSS satellites

National/Regional Multi-GNSS Tracking – July 2013

Upgrading our network is a multi-year project

Satellite Laser Ranging (SLR) SLR, Mount Stromlo, Canberra  GNSS (cm-level) orbits can be validated using SLR  SLR observations of GNSS have made important contribution to satellite force modelling  Independent orbit accuracy assessment

Satellite Laser Ranging (SLR)  International Laser Ranging Service (ILRS) tracking priorities as of 1 July 2013  GPS: gps36  QZSS: qzs1  COMPASS: compassm3, compassi3, compassi5, compassg1  GLONASS: glonass129, glonass130, glonass102, glonass109, glonass110  Galileo: galileo104, galileo103, galileo101, galileo102, giovea  Challenge: additional tracking of GNSS using the same SLR resources

Network Operations  UNAVCO TEQC software  software developed and supported at UNAVCO for “translation, editing, quality check” of GNSS data  Used extensively in the IGS community  TEQC built into many internal Geoscience Australia data management and quality assurance processes  TEQC is limited to RINEX 2.x and will not be upgraded to RINEX 3  RINEX 2.x doesn’t support the complexities of multi-GNSS  Re-engineering GA’s data management and quality assurance processes while maintaining normal operations is not a trivial task

Communications Issues  More signals and data  Emergence of supported multi-GNSS formats has been slow  Long-term (data limited) contracts  Often share links with other Geoscience Australia projects to keep costs lower  Australian Tsunami Warning System (ATWS)  Carefully manage communication saturation Nauru VSAT Norseman Next-g

Global Reference Frame Issues Antenna Change 1, 5, 15 mm (ENU) IGS Reference Frame Core Stations

GNSS Antenna Calibrations  Antenna hardware (elements and preamplifiers) cause phase advance and delay  Phase advance and delay changes cause range bias and consequently impact position determination  Antenna type/model and individual antenna dependent

GNSS Antenna Calibrations  Current capability based around L1 and L2 on GPS + all GLONASS  New antennas  New signals and frequencies present challenges  No L5 GPS

Legal Traceability of GPS in Australia

Legal Issues of using GPS in Australia  What about the other GNSS?

Challenges: Many network operators  Standardisation  Coordinates – National Reg 13 Campaign  Data access policies  Data management

Challenges: International Engagement National security implications Many stakeholders to manage Different objectives (and challenge of communication)

Multi-GNSS Analysis  No Australian ‘operational’ sovereign capability to process GNSS  No communications infrastructure to deliver precise corrections – any where in Australia and its maritime jurisdictions

A multi-GNSS National Positioning Infrastructure (NPI) New analysis approaches Integrating and managing GNSS networks Working across government and private sectors Expectation of high reliability Hardware and Software components High user expectations Developing new models for sustainability New and challenging use cases International coordination