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Australian CRS · advisory

GDA2020, GDA94 and MGA review support for survey workflows

SurveyMarkup can surface the coordinate reference selections that travel with survey linework — GDA2020, GDA94, MGA zones and AUSGeoid/AHD notes — so mismatches are easier to catch during review. CRS handling is a preview aid; outputs remain unverified.

Advisory only

Advisory and unverified — not for survey deliverables. A registered surveyor must confirm any output before it is relied on.

What SurveyMarkup can flag or organise

  • The datum and zone a dataset declares
  • CRS metadata that disagrees with the linework
  • AUSGeoid / AHD references for review

What it cannot prove or certify

  • It does not verify coordinates are correct
  • It does not perform authoritative datum transformations
  • It does not certify CRS selection for a deliverable

GDA2020, GDA94 and the MGA grid

Review which datum and zone a dataset declares. Where precision matters, MGA2020 describes the grid associated with GDA2020. SurveyMarkup surfaces these selections; it does not transform or re-compute authoritative coordinates.

  • GDA2020 and GDA94 datum notes
  • MGA zones 49–56
  • AUSGeoid and AHD references

Catch CRS mismatches before export

When a project's declared CRS and its linework metadata disagree, that is exactly the kind of thing a reviewer wants flagged before a CAD or GIS handoff.

What stays the surveyor's call

Datum choice, zone correctness and transformation suitability remain professional decisions. SurveyMarkup previews metadata; it does not confirm coordinate correctness.

Worked example · synthetic

A dataset arrives declaring GDA2020 / MGA Zone 56.

What SurveyMarkup surfaces

  • The declared datum and zone shown for review
  • An AHD / AUSGeoid note alongside the heights
  • A point whose easting falls outside the declared zone band — worth checking

Reviewer's call: The surveyor confirms the datum, zone and any transformation. SurveyMarkup previewed the metadata only and did not verify the coordinates.

Frequently asked questions

Does it transform GDA94 to GDA2020?

No. It previews CRS metadata for review. Authoritative transformations and their suitability remain a registered surveyor's responsibility.

Which MGA zones are covered?

MGA zones 49–56 are recognised for preview purposes alongside GDA2020 / GDA94 and AUSGeoid / AHD notes.

Can I rely on the previewed coordinates?

No. Coordinate outputs remain unverified and must be confirmed before any professional use.

Related survey workflows

Related next steps

View the CRS preview in Map Linework

Advisory and unverified — not for survey deliverables. A registered surveyor must confirm any output before it is relied on.

Ready to review with SurveyMarkup?

Every output stays advisory and unverified — not for survey deliverables; registered surveyor confirmation required.

View the CRS preview in Map Linework