National Measurement (Recognized-Value Standard of Measurement of Position) Determination 2026

This instrument, the National Measurement (Recognized-Value Standard of Measurement of Position) Determination 2026, formally declares a set of geodetic coordinates, velocities and associated uncertainties as recognized-value standards of measurement of the physical quantity position for stations in the Australian Fiducial Network (AFN). It was made by the Chief Metrologist, Dr Victoria Anne Coleman, and is dated 9 March 2026 (instrument header). The instrument takes effect the day after it is registered, for the whole instrument (s 2). It is made under paragraphs 8A(1)(a) and (b) of the National Measurement Act 1960 (s 3).

Mechanically the determination does four things, each established in the instrument text. First, it defines the Reference Ellipsoid as the Geodetic Reference System 1980 (GRS80) with stated semi-major axis and inverse flattening, and the Reference Epoch as 2020.0 (s 5). Second, it defines the Reference Frame for the declared values as the Geocentric Datum of Australia 2020 (GDA2020) realised by the coordinates of the AFN geodetic stations listed in Schedule 1 in the International Terrestrial Reference Frame 2014 (ITRF2014) at the Reference Epoch (s 5). Third, it lists for each AFN site in Schedule 1 global Cartesian coordinates (X, Y, Z) at epoch 2020.0, 3-component velocity estimates (VX, VY, VZ) in metres per year, and uncertainties for coordinates and velocities; those listed positions and associated data are declared, by s 6(1) and Schedule 1, to be the recognized-value standards of measurement. Fourth, it prescribes the propagation model by which global Cartesian coordinates of the AFN can be computed for an arbitrary epoch t years, X_t = X_2020 + (t − 2020)·V (s 7), and makes that model valid only for |t − 2020| ≤ 15 years (s 7).

The instrument also states conventions: the uncertainties in Schedule 1 are such that X ± u(X) represents a 95% confidence interval (s 6(2)); and conversions from global Cartesian coordinates to latitude, longitude and ellipsoidal height must use the defined Reference Ellipsoid (s 6(3)). Finally, the instrument expressly repeals the prior National Measurement (Recognized-Value Standard of Measurement of Position) Determination 2017 in its entirety (Schedule 2).

Those are the mechanical changes set by the instrument. The instrument does not itself create offences, tariffs, registration regimes or explicit compliance sanctions; it operates by declaring measurement standards and providing the numerical realisation and procedures that users may adopt. The legal basis for its authority is the National Measurement Act 1960, not restated in the instrument beyond the cited paragraphs of s 8A, and the instrument relies on that Act’s definition of recognized-value standard of measurement (s 5 note).

The instrument establishes and ties together five principal technical concepts: Reference Ellipsoid, Reference Epoch, Reference Frame, recognized-value standards, and the epoch propagation model.

Reference Ellipsoid. Section 5 defines the Reference Ellipsoid as GRS80 with a semi-major axis a = 6 378 137 metres exactly and inverse flattening 1/f = 298.257 222 101. That ellipsoid is explicitly mandatory for conversion from Cartesian coordinates to geographic coordinates, by s 6(3). The instrument does not specify any alternative ellipsoid for conversions.

Reference Epoch. The Reference Epoch is defined as 2020.0 (s 5). Coordinates in Schedule 1 are explicitly "Coordinates (m) at 2020.0" (Schedule 1 header), so the listed X, Y and Z values are tied to that epoch.

Reference Frame. The instrument defines the Reference Frame as GDA2020 realised by the coordinates of the AFN stations listed in Schedule 1, referred to ITRF2014 at the Reference Epoch (s 5). In other words, the declared positions are realised within GDA2020 and are referred to the ITRF2014 coordinate system at 2020.0. The instrument cites these international references in notes only; it does not attempt to amend those external reference frame definitions.

Recognized-value standards of measurement. Section 6(1) declares the positions listed in Schedule 1, and in the stated Reference Ellipsoid and Reference Frame, to be recognized-value standards of the physical quantity position for AFN geodetic stations. The instrument notes that "Recognized-value standard of measurement is defined in the Act" (s 5 note), so the technical status given here attaches to the statutory definition in the National Measurement Act 1960.

Uncertainties and confidence. Section 6(2) states that uncertainties listed in Schedule 1 are such that X ± u(X) represents a 95% confidence interval, and similarly for other quantities. Schedule 1 therefore gives users both central estimates and 95% confidence bounds for each coordinate and velocity component.

Epoch propagation model and validity interval. Section 7 prescribes a linear model to compute global Cartesian coordinates at an arbitrary epoch t: (X_t, Y_t, Z_t) = (X_2020, Y_2020, Z_2020) + (t − 2020)·(VX, VY, VZ). The instrument then limits application of this linear model to within 15 years either side of the Reference Epoch, that is for |t − 2020| ≤ 15 (s 7). That constraint is an explicit validity window for using the velocity-based linear propagation without additional corrections.

Schedule structure and contents. Schedule 1 lists for each AFN site a site code, site name, nominal location (state/territory or external territory in many entries), the X, Y, Z coordinates at 2020.0 in metres, the coordinate uncertainties u(X), u(Y), u(Z) in metres, the velocity components VX, VY, VZ in metres per year and their uncertainties u(VX), u(VY), u(VZ). The schedule covers multiple mainland and external-station sites, and thereby provides a comprehensive realisation of GDA2020 for AFN stations.

The instrument’s express scope, in s 6(1), is the AFN geodetic stations listed in Schedule 1 because those positions are declared to be recognized-value standards of measurement of position for those stations. The immediate effects are therefore on the custodians, operators and users of the AFN, and on any person or entity that chooses to rely on the declared recognized-value standards for positioning, geodesy, surveying, mapping, or other activities where statutory recognized-value standards are relevant.

More concretely, the following categories of parties will be affected in operation or practice by the declaration and the numbers it contains, as a direct consequence of the instrument’s content:

• AFN station operators and maintainers, because the instrument provides the official Cartesian coordinates, velocities and uncertainties to be taken as the recognized-value realisation for those stations (s 6(1), Schedule 1).
• Organisations and professionals that use AFN values as the authoritative reference for positioning, including surveyors, state mapping authorities, spatial-data custodians and infrastructure project managers, where they have chosen to adopt recognized-value standards for legal, technical or contractual reasons. The instrument provides the numerical values and the propagation model they must use if they adopt the declared AFN realisation (s 7).
• Users of geodetic products and services that depend on GDA2020/ITRF2014 realisations, such as precision positioning and GNSS augmentation services, insofar as those services align their output to the AFN recognized values listed in Schedule 1.
• Entities that previously relied on the 2017 determination: Schedule 2 repeals the 2017 determination in whole, so parties who had systems keyed to the previous declared values will need to transition to the 2026 declared values if they intend to rely on the instrument as the current recognized-value standard.
• Any downstream systems, contracts, cadastral reference systems or statutory frameworks that explicitly refer to the National Measurement recognized-value determinations, to the extent those instruments are used as the official numerical realisation for position.

The instrument itself does not list specific duties for third parties to adopt or reference it, and it does not name non-AFN parties by statutory obligation. Its effect is to provide an authoritative set of numerical standards which operators and users can adopt. Practically, anyone who needs to produce or certify measurements "to the recognized-value standard" for AFN stations will be affected because the instrument defines the numerical realisation and the method to propagate to other epochs (s 6, s 7).

The determination is primarily declaratory and prescriptive about measurement realisation rather than prescriptive about general legal obligations beyond the immediate technical requirements it sets. From the instrument text the following duties and rights flow directly.

Duties explicitly stated in the instrument

• Use of the Reference Ellipsoid for conversion: Section 6(3) imposes a mandatory technical convention, that for conversion from global Cartesian coordinates to latitude, longitude and ellipsoidal height the Reference Ellipsoid defined in s 5 must be used. That is an explicit duty on anyone carrying out such conversions if they are to follow the instrument’s conventions.
• Use of the listed coordinates and velocities and propagation model: Section 7 prescribes the linear propagation model for obtaining Cartesian coordinates at epoch t, using the X, Y, Z coordinates and VX, VY, VZ velocities listed in Schedule 1. Practitioners required or choosing to adopt the recognized-value standards will therefore be obliged to apply that formula when computing epoch-based Cartesian positions for AFN stations.
• Respecting the model validity window: Section 7 also imposes an explicit constraint on the model, limiting its validity to ±15 years from Reference Epoch 2020.0. Users must therefore not apply the linear model beyond that interval if they intend to remain within the instrument’s stated validity.

Declared rights or statuses

• Recognized-value status: Section 6(1) grants the declared positions, velocities and uncertainties the status of "recognized-value standards of measurement" for AFN geodetic stations, as that phrase is defined in the Act (s 5 note). That gives the Schedule 1 numbers special status under the Act’s recognised-value mechanism. The instrument does not itself set out the legal consequences of that status; those consequences derive from the Act’s definition and provisions outside this instrument.

Informational duties and conventions

• Uncertainty confidence level: Section 6(2) specifies that the uncertainties in Schedule 1 are to be interpreted as 95% confidence intervals. Users must adopt that statistical convention when reporting or interpreting the Schedule 1 uncertainty values.

Duties not created by the instrument

• The instrument does not create offence provisions, monetary penalties, registration requirements, or compliance inspection regimes; it is not framed as a regulatory enforcement instrument but as a standards determination. Any enforcement or sanctions would depend on other provisions of the National Measurement Act or other legislation, which are not restated here. The instrument itself is silent on enforcement mechanics.

The instrument itself contains no express penalty, offence or enforcement mechanisms. It is a standards determination made under the National Measurement Act 1960 (s 3), and its text focuses on defining technical realisation, uncertainty conventions and propagation procedures. The following points summarise the enforcement-related material that does appear in, or is implied by, the instrument’s content:

No in-instrument sanctions. Nowhere in the instrument are criminal offences, civil penalty clauses, infringement notices or administrative fines specified. The instrument does not specify a compliance regime, inspection powers, or administrative processes for monitoring adherence to the declared recognized-value standards.

Authority and source of any enforcement. Section 3 states that the instrument is made under paragraphs 8A(1)(a) and (b) of the National Measurement Act 1960. Any enforcement, regulatory consequences or legal effects beyond the declaration of recognized-value standards will depend on the provisions of that Act and other applicable legislation. The instrument does not reproduce or summarise those enforcement provisions. Practitioners requiring an understanding of statutory enforcement mechanisms must therefore consult the National Measurement Act 1960 and secondary legislation or administrative guidance issued under it.

Practical effect on contracts, certifications and statutory processes. Although the determination itself contains no sanctions, the instrument’s declaration of specific numbers as "recognized-value standards" means that, where another statutory provision, contract or certification criterion refers explicitly to recognized-value standards under the Act, parties relying on those references will need to apply the Schedule 1 values and the conversion/propagation conventions laid out in this instrument to maintain conformity. Non-conformity in contexts where adoption of recognized values is required by other legal instruments could lead to legal or contractual consequences, but those consequences derive from the referencing instrument rather than from the determination text.

Administrative decision-maker. The instrument highlights who made the decision: Dr Victoria Anne Coleman, Chief Metrologist (instrument header). The Chief Metrologist’s authority to make such determinations is the basis for the instrument, but the text does not specify any enforcement role or follow-up compliance process for that office in relation to this determination.

Transition and repeal enforcement. Schedule 2 repeals the 2017 determination in whole. There is no transitional enforcement provision in the instrument setting a grace period beyond the commencement rule in s 2 (the instrument commences the day after registration). As a result, entities that had previously functioned under the 2017 declared values should treat the 2017 instrument as superseded on commencement. The instrument does not set out dispute resolution, correction or review procedures in relation to the declared numbers.

This instrument is an exercise of the Chief Metrologist’s power under the National Measurement Act 1960. The instrument explicitly invokes paragraphs 8A(1)(a) and (b) as its statutory authority (s 3), and it notes that "Recognized-value standard of measurement is defined in the Act" (s 5 note). Beyond that anchoring, the instrument does not itself restate, amend or directly cross-reference other statutes or subordinate instruments except for the repeal of the 2017 determination (Schedule 2). The following interactions and interfaces are present or implied by the text:

Statutory source. The instrument must be read as a statutory instrument under the National Measurement Act 1960. The legal meaning and consequences of its declaration of "recognized-value standards" therefore depend on the Act’s definitions and provisions. The instrument does not attempt to restate the Act’s operative provisions or to modify them.

Repeal of prior instrument. Schedule 2 repeals the earlier National Measurement (Recognized-Value Standard of Measurement of Position) Determination 2017 wholly. That produces a clear statutory sequencing: the 2017 declared values are no longer in force once the 2026 determination commences (s 2, Schedule 2). Parties who had aligned to the 2017 instrument will need to transition to this instrument if they are to rely on the current recognized-value standard.

Reference frames and international realisations. The instrument ties the AFN realisation to GDA2020 and ITRF2014 at Reference Epoch 2020.0 (s 5). Those names correspond to internationally recognised geodetic frames. The instrument does not amend or govern those external frameworks; rather it declares that the AFN recognised-value realisation is to be interpreted in the context of those frames. Practitioners who must reconcile other statutory or contractual coordinate frames with GDA2020/ITRF2014 will need to perform datum transformations external to this instrument.

Cadastral, property and planning regimes. The instrument does not mention cadastral law, land titles, planning or other areas that typically rely on coordinate systems. Nevertheless, where other laws or contracts make express reference to recognized-value standards of measurement under the National Measurement Act, or where government agencies require alignment with national geodetic realisations, the declared values in Schedule 1 will be the operative numbers for those references. The instrument does not itself amend cadastral statutes or land registration rules; it simply supplies the declared numerical realisation. Any legal effect in those domains therefore flows from the other statutes or contractual instruments that incorporate or rely on the declared recognized-value standards.

The instrument itself contains minimal amendment-history metadata, but it does include explicit repeal of a predecessor instrument and identifies its date and commencement. The following items in the text record the amendment and succession history provided:

• Instrument date and maker. The instrument is dated 9 March 2026 and is signed by Dr Victoria Anne Coleman, Chief Metrologist (instrument header). That records who made the instrument and when.
• Commencement. Section 2 provides that the whole of the instrument commences the day after the instrument is registered. The instrument’s table of commencement is minimal and notes that it relates only to provisions as originally made (s 2).
• Repeal of the 2017 determination. Schedule 2 repeals the National Measurement (Recognized-Value Standard of Measurement of Position) Determination 2017 in whole. Schedule 2’s operative line is "Repeal the determination," with the subject being the 2017 determination. That is the single express amendment-history item included.
• Schedules and content update. Schedule 1 replaces the earlier list of recognized-value coordinates and velocities with a new list that specifies coordinates at epoch 2020.0, velocities, and uncertainties. The instrument does not include a marked comparison or a track-change history, it simply provides the new Schedule 1 and repeal of the older instrument.

What the instrument does not include about amendment history

• The instrument does not list prior amendments to itself, nor does it include a version history for the AFN realisation prior to 2017. It only identifies the repealed 2017 determination and replaces it.
• There is no transitional schedule setting out the steps for migrating from the 2017 numbers to the 2026 numbers; the repeal is absolute in Schedule 2, and commencement is the day after registration (s 2).
• The instrument does not provide an expiry date for this determination. It does, however, constrain the validity of its linear propagation model to ±15 years from 2020.0 (s 7). That technical constraint signals that expected practice is to reassess or re-realise the AFN at intervals aligned to that window, but the instrument does not itself state when the next determination will be made.

Practical implication for document control and systems

• Organisations that maintain spatial reference documentation, technical specifications, contracts or data systems with references to National Measurement recognized-value determinations should update references that cite the 2017 determination to refer to the 2026 instrument and Schedule 1 values from its commencement date (s 2, Schedule 2).

The instrument text contains no information about litigation history. It names no cases, and it does not reference any judicial decisions or legal disputes relating to the recognized-value standards, the AFN, the Reference Frame, or the Chief Metrologist’s decision-making. The instrument is silent on any prior or ongoing litigation.

What is provided in the instrument that is relevant to litigation risk

• The instrument explicitly ties the declared values to the National Measurement Act 1960 (s 3) and notes that the phrase "Recognized-value standard of measurement is defined in the Act" (s 5 note). Any challenge to this determination’s legal effect would therefore need to engage with the Act and the statutory powers cited at paragraphs 8A(1)(a) and (b), though the instrument itself does not outline procedural protections, review mechanisms or appeal rights.
• The instrument sets numerical values, uncertainty conventions and a propagation model. Disputes in technical settings commonly turn on measurement conventions, uncertainty interpretation, datum transformations, or on whether a party correctly applied the declared model within its valid interval (|t − 2020| ≤ 15). The instrument defines the conventions that would be relevant in such technical disputes (s 6(2), s 6(3), s 7).
• Repeal of the 2017 determination (Schedule 2) could, in theory, occasion transitional disputes over which numbers a party should have relied upon for a given task if work straddled the repeal date, but the instrument does not provide transitional arrangements and is silent on dispute resolution.

Practical note for practitioners

• Because the instrument contains authoritative numerical values and prescriptive conversion and propagation rules, in any litigation or technical arbitration where recognized-value standards play a role, Schedule 1 and the sections on conversion and propagation (s 6, s 7) will be primary documentary evidence. The instrument itself does not supply an administrative review route or a litigation history; if a practitioner requires information on any challenges made to such determinations historically, they will need to consult court or tribunal databases or administrative records outside this instrument.

In sum, the instrument records no litigation history and contains no litigation-related material; it defines technical standards that would become evidentially important in any dispute but offers no record of prior legal contests in its text.

This instrument is technically concise but contains several provisions and conventions that can create operational pitfalls if overlooked. The following are concrete "gotchas" drawn directly from the instrument’s text and schedules.

Epoch dependence and limited propagation window. The coordinates in Schedule 1 are given explicitly at Reference Epoch 2020.0 (s 5; Schedule 1 header). The linear velocity propagation model in s 7 is valid only for |t − 2020| ≤ 15 years. That means the simple linear model must not be applied beyond 15 years before or after 2020.0 without further justification or correction. If a user applies the linear model for t outside that window, they are using the model beyond its stated validity.

Mandatory ellipsoid for conversion. Section 6(3) requires that conversions from global Cartesian coordinates to latitude, longitude and ellipsoidal height use the Reference Ellipsoid GRS80 defined in s 5. Using a different ellipsoid for this conversion will not conform to the instrument’s stated conversion convention.

Uncertainties are 95% confidence intervals. Section 6(2) specifies that the listed uncertainties represent a 95% confidence interval. Users that interpret those u(·) values as, for example, 1-sigma standard deviations, median absolute deviations or other statistical measures will misinterpret the instrument’s stated statistical convention.

Velocities and their precision. Schedule 1 provides velocities in metres per year with uncertainties reported, typically 0.0002 for many entries. Those small uncertainty figures indicate the instrument intends a high-precision propagation practice. Implementations must ensure numerical precision in software and data types to avoid rounding or truncation errors when using velocities and propagating positions.

Repeal of 2017 Determination. Schedule 2 repeals the 2017 determination in whole. Parties who continue to use 2017 numbers after the 2026 instrument commences risk relying on a superseded statutory realisation. There is no transitional clause in the instrument; the commencement rule applies the day after registration (s 2).

Reference Frame and external dependencies. The Reference Frame is defined as GDA2020 realised by the AFN coordinates and referred to ITRF2014 at the Reference Epoch (s 5). Practical use often requires datum transformations between other frames or older realisations. The instrument does not provide transformation parameters to older frames or other national/subnational datums; users must source or compute those transformations separately.

Interpretation of "recognized-value standard" legal consequences. The instrument expressly points out that the phrase is defined in the Act (s 5 note) but the instrument does not set out what legal consequences follow from recognized-value status. Practitioners should not assume automatic legal effects beyond those in the Act without consulting the Act itself.

If your organisation, project or system needs to adopt or align with the recognized-value standards declared by this determination, the instrument itself prescribes the technical steps and conventions to follow. The practical compliance checklist below is a direct readout of the instrument’s operative requirements.

1. Confirm commencement date and legal reliance. Section 2 states the whole instrument commences the day after it is registered. Ensure you are referencing the 2026 determination from its commencement date and that any prior references to the 2017 determination have been updated, because Schedule 2 repeals the 2017 determination in whole.

2. Use the Reference Epoch and Schedule 1 numbers. Schedule 1 provides coordinates (X, Y, Z) for each listed AFN site at Reference Epoch 2020.0 (s 5 and Schedule 1 header). When your system needs the authoritative AFN Cartesian coordinates at epoch 2020.0, consume the X, Y, Z columns from Schedule 1 for the appropriate site code.

3. Apply the epoch propagation model exactly as stated. Section 7 prescribes the linear model: (X_t, Y_t, Z_t) = (X_2020, Y_2020, Z_2020) + (t − 2020)·(VX, VY, VZ). Use the VX, VY, VZ velocity components from Schedule 1 and compute t as the decimal year of the epoch you need. Do not apply the model for |t − 2020| > 15 years, because s 7 limits the model’s validity to that interval.

4. Respect the conversion ellipsoid convention. For conversion from global Cartesian coordinates to latitude, longitude and ellipsoidal height, use the Reference Ellipsoid defined in s 5, the Geodetic Reference System 1980 (GRS80) with a = 6 378 137 m exactly and 1/f = 298.257 222 101. That conversion rule is mandatory in s 6(3).

5. Interpret uncertainties as 95% confidence intervals. Section 6(2) states that u(X) and the other u(·) values in Schedule 1 are 95% confidence intervals. When reporting errors, uncertainty budgets, or confidence statements, adopt that statistical convention.

6. Preserve numeric precision and units. Schedule 1 uses metres for coordinates, metres per year for velocities, and metres for uncertainties. Implementations should use appropriate data types (double precision or better) to avoid rounding errors when applying velocities (which are small but cumulative) and when combining uncertainties.

7. Update documentation and contractual references. If technical specifications, contracts or compliance documents previously referred to the 2017 determination, revise those references to cite the 2026 Determination and Schedule 1 values as appropriate, taking into account the instrument’s commencement and repeal rule (s 2, Schedule 2).