EXPLANATORY STATEMENT
Issued by the Authority of the Chief Metrologist
National Measurement Act 1960
National Measurement (Recognized-Value Standard of Measurement of Position) Determination 2026
Purpose and Operation
The purpose of the National Measurement (Recognized-Value Standard of Measurement of Position) Determination 2026 (the determination) is to formalise units of measurement through the development and maintenance of standards of measurement, reference materials and reference techniques and to promote uniformity in national measurement policy and practice.
The National Measurement (Recognized-Value Standard of Measurement of Position) Determination 2017, made by the Chief Metrologist, dated 11 October 2017 (2017 determination), is repealed in the determination pursuant to subsection 8A(2) of the National Measurement Act 1960 (the Act).
The position of Chief Metrologist is established, and the functions of the Chief Metrologist identified, in section 18A of the Act. Subsection 8A(1) of the Act gives the Chief Metrologist the power to determine that magnitudes of physical quantities specified in the determination and magnitudes of physical quantities as ascertained in accordance with a formula set out in the determination shall be recognized-value standards of measurement.
Subsection 8A(4) of the Act provides that a recognized-value standard of measurement is not subject to verification. This means that the magnitude of the physical quantity of the recognized-value standard is deemed to be that which is determined by the Chief Metrologist. A recognized-value standard of measurement is not determined by reference to, comparison with, or derivation from another standard of measurement.
The determination specifies the magnitudes of physical quantities of the recognized-value standard measurement of position in the Australian Fiducial Network (AFN) as specified in Schedule 1 of the determination.
The Australian Plate is moving in a north-easterly direction at a rate of about 70 millimetres per year. As a result, improvements are required in the way spatial data are managed to support applications that use global navigation satellites systems (GNSS) such as global positioning systems (GPS). This is important in applications that rely on accurate satellite data for real-time positioning such as in-vehicle navigation; smartphone location services; automated mining operations; precision agriculture; and surveying.
This determination aligns with the most recent realisation of the International Terrestrial Reference Frame (ITRF). The ITRF is realised from space geodesy observations and has been iteratively updated with better estimates of coordinates and velocities of global stations over time.
The determination will support surveyors and other users of legally traceable measurements of position by ensuring consistency between the most up-to-date systems and infrastructure and the recognized-value standard of measurement of position.
The costs associated with incorporating the revised values of the AFN positions into the operations of surveyors and other users of precise legally traceable measurement of position are minimal, and form part of the normal cost of maintaining up-to-date capabilities for these stakeholders.
The Intergovernmental Committee on Surveying and Mapping (ICSM) is responsible for the technical elements of modernising Australia’s datum. In September 2015, the ICSM formed a dedicated working group to oversee the implementation of the modernisation of the Geocentric Datum of Australia (GDA). The GDA Modernisation Implementation Working Group (GMIWG) has government representatives from the Commonwealth, States and Territories who have a broad range of knowledge and experience in the surveying and spatial sciences industry. The group has consulted widely with users and has developed tools and technical resources needed to assist with the datum transition. It has worked to ensure that the practical implementation of the datum occurs seamlessly and with minimal disruption to existing systems and processes.
Further details of the determination are outlined in Attachment A.
Authority
The determination is made by the Chief Metrologist, National Measurement Institute, under paragraphs 8A(1)(a) and (b) of the Act. The determination is a legislative instrument for the purposes of section 8 of the Legislation Act 2003 (Cth).
Consultation
Geoscience Australia, as the Commonwealth Government agency with responsibility for developing and maintaining the AFN, were consulted in the development of the determination and support that the updates contained in the determination that formalise the positions in the AFN, reflecting the most recent realisation of the ITRF, as developed by ICSM.
In response to the ongoing work carried out by ICSM and the GMIWG, Geoscience Australia recommended that the 2017 determination be re-made to reflect the most recent realisation of the ITRF. The 2017 determination was due to sunset on 1 April 2026. The 2026 determination provides updated magnitudes of physical quantities of the recognized-value standard measurement of position in the AFN as specified in Schedule 1 of the determination.
The National Measurement Institute also undertook public consultation from November to December 2025 to inform the remade 2026 Determination. The consultation ran from November 24, 2025 to December 24, 2025and was targeted towards stakeholders who currently reference the existing instrument, including government agencies, measurement laboratories, and industry bodies. Three submissions were received, each of which supported the proposed changes to the instrument to reflect the updated ITRF.
Statement of Compatibility with Human Rights
A Statement of Compatibility with Human Rights is set out at Attachment B.
Attachment A
Details of the National Measurement (Recognized-Value Standard of Measurement of Position) Determination 2026
Section 1—Name
This section provides that the name of the determination is the National Measurement (Recognized-Value Standard of Measurement of Position) Determination 2026.
Section 2—Commencement
This section provides that the determination commences the day after registration.
Section 3—Authority
This section provides that the authority for the making of the determination is paragraphs 8A(1)(a) and (b) of the National Measurement Act 1960 (the Act).
Section 4— Schedules
This section is a machinery provision that gives effect to the provisions in the Schedules to the determination.
Section 5— Definitions
This section sets out the definitions for terms referred to in the determination as follows:
Act means the National Measurement Act 1960.
Reference Ellipsoid means the Geodetic Reference System 1980 (GRS80) ellipsoid with a semi-major axis (a) of 6 378 137 metres exactly and an inverse flattening (1/f) of 298.257 222 101.
Note: The Geodetic Reference System 1980 could in 2026 be viewed on the International Union of Geodesy and Geophysics (IUGG) website (http://www.iugg.org).
Reference Epoch means 2020.0.
Reference Frame means the Geocentric Datum of Australia 2020 (GDA2020) realised by the coordinates of the Australian Fiducial Network (AFN) geodetic stations, referred to in Schedule 1 of this instrument, in the International Terrestrial Reference Frame 2014 (ITRF2014) at the Reference Epoch.
Note 1: The Geocentric Datum of Australia 2020 could in 2026 be viewed on the Intergovernmental Committee on Surveying and Mapping’s website (http://www.icsm.gov.au).
Note 2: The International Terrestrial Reference Frame 2014 (ITRF2014) could in 2026 be viewed on the International Earth Rotation and Reference Systems Service’s (IERS) website (https://www.iers.org).
The legislative note underneath the definition for Reference Ellipsoid makes clear that the Geodetic Reference System 1980 (GRS80) can be viewed on the International Union of Geodesy and Geophysics (IUGG) website (https://iugg.org/publications/resolutions/). The Geodetic Reference System 1980 (commonly abbreviated to GRS80) is a geodetic reference system consisting of a global reference ellipsoid and a gravity field model. The GRS80 was adopted at the XVII General Assembly of the IUGG in Canberra, Australia, 1979. The exact reference to the GRS80 on the IUGG website is Canberra 1979, Resolution 7.
The first legislative note underneath the definition for Reference Frame makes clear that the Geocentric Datum of Australia 2020 (GDA2020) is available at the Intergovernmental Committee on Surveying and Mapping’s website (http://www.icsm.gov.au/). The GDA2020 is realised by the coordinates of the Australian Fiducial Network (AFN) geodetic stations. The Geocentric Datum of Australia 2020 is the most modern geodetic datum for Australia.
The second legislative note underneath the definition for Reference Frame makes clear that the International Terrestrial Reference Frame 2014 (IRTF2014) can be accessed at the IERS website (https://www.iers.org/IERS/EN/DataProducts/ITRF/itrf.html). The ITRF2014 is maintained by the International Earth Rotation and Reference Systems Service (IERS) and is an international spatial reference system co-rotating with the Earth in its diurnal motion in space.
Section 6—Recognized-value standards of measurement in the Australian Fiducial Network
This section sets out the Recognized-value standards of measurement.
Subsection (1) specifies the recognized-value standards of measurement in the Australian Fiducial Network (AFN) are the positions listed in Schedule 1, and as stated in the Reference Ellipsoid and Reference Frame.
Subsection (2) sets out the equation for uncertainties listed in Schedule 1, which represents a 95% confidence interval for the uncertainties of those quantities. This similarly is the case for other quantities.
Subsection (3) provides that the Reference Ellipsoid must be used to convert from global Cartesian coordinates to latitude, longitude and ellipsoidal height.
Section 7—Calculation of global Cartesian coordinates at an epoch t years
This section provides the formula to express the global Cartesian coordinates of the AFN at any epoch t (years) using the linear model set out in this section. This section makes clear that this model is valid for 15 years either side of the Reference Epoch.
Schedule 1—Recognized-value standards of measurement in the Australian Fiducial Network
Schedule 1 sets out a table of Recognized-value standards of measurement in the AFN, which includes the coordinates, coordinate uncertainties, velocities and velocity uncertainties for geodetic stations throughout Australia, and its external territories. The uncertainties in this table are estimated to give a 95% confidence interval (see section 6 above).
Schedule 2—Repeals
Item 1 repeals the National Measurement (Recognized-Value Standard of Measurement of Position) Determination 2017.
Attachment B
Statement of Compatibility with Human Rights
Prepared in accordance with Part 3 of the Human Rights (Parliamentary Scrutiny) Act 2011
National Measurement (Recognized-Value Standard of Measurement of Position) Determination 2026
This Legislative Instrument is compatible with the human rights and freedoms recognised or declared in the international instruments listed in section 3 of the Human Rights (Parliamentary Scrutiny) Act 2011.
Overview of the Legislative Instrument
The National Measurement (Recognized-Value Standard of Measurement of Position) Determination 2026 (the determination) supports the national measurement system by formalising units of measurement through the development and maintenance of standards of measurement, reference materials and reference techniques and to promote uniformity in national measurement policy and practice. The determination specifies the magnitudes of physical quantities of the recognized-value standard measurement of position in the Australian Fiducial Network (AFN) as specified in Schedule 1 of the determination.
Human rights implications
This Legislative Instrument does not engage any of the applicable rights or freedoms.
Conclusion
This Legislative Instrument is compatible with human rights as it does not raise any human rights issues.
Dr Victoria Anne Coleman
Chief Metrologist