Reference sets are your surveyed control — the GCPs and prisms you've established on site — stored against the site itself rather than against a single map.
Upload the coordinates once, and they're available to every map of that location, now and in future.
This article covers:
downloading the CSV template for GCP and prism sets
uploading a set and choosing the coordinate system it was exported in
how versions work when you re-survey
downloading a set as CSV, GeoJSON or a PDF report
Note: GCP management & visualisation (Requires Growth or Ultimate plan) and prism reference sets (Require our Ultimate plan) GCP sets and prism sets are separate features, so your organisation may have one without the other.
Sites themselves are available on all paid plans.
When to use reference sets
You've surveyed permanent GCPs on a site and want them visible on every map of that location.
You monitor with prisms — wall, embankment or structure prisms read on a schedule — and want them on the map alongside your imagery.
You want control that survives the map. Reference sets belong to the site, so a new map starts with your control already available.
You re-survey periodically and need a record of what each point was, each time it was measured.
You want to share coordinates with your team without emailing a spreadsheet around.
Step-by-step: uploading a reference set
1. Open your site
Open the site from the dashboard sidebar or the Map Browser, then go to its Reference sets.
2. Download the CSV template
Before you upload anything, download the CSV template for the type of set you're adding — GCP or prism.
The templates are different, so download the one that matches your set.
For GCP's we can visualise different types of control and check points. Under type please use the below:
Type | Icon | CSV Field |
Prism |  |
|
GCP Locations |  |
|
Check Points |  |
|
Elevation Points |  |
|
Max Elevation |  |
|
Min Elevation |  |
|
TLZ Area |  |
|
Auscors Site |  |
|
PSM Location |  |
|
Tip: Give the template to whoever does your survey work and ask them to export straight into it. That single step removes almost every upload error described further down.
3. Fill in your coordinates
Copy your surveyed values into the template — one row per point.
Keep in mind:
Every point needs a unique ID. This is what you'll see on the map and what links a point across re-surveys.
Export in one coordinate system. Don't mix systems within a file.
Don't rename or reorder the columns. Birdi reads the template's columns as they are.
4. Upload the CSV
Select Upload and choose your file.
5. Choose the coordinate system
Choose the coordinate system your CSV was exported in — not the one you'd like it displayed in.
This is the step to get right. Birdi transforms your coordinates from the system you nominate, so nominating the wrong one puts every point in the wrong place.
Note: If the site already has an earlier version of this set, the coordinate system defaults to the previous version's. That's usually correct — but check it if your survey workflow or export settings have changed since.
For background on how Birdi handles transformations and geoids, see How we handle coordinate systems, GCPs, and geoids in Birdi.
6. Add a note
Add a note on upload. This becomes that version's description — the one line of context that tells you, months later, what this upload was.
Good notes:
Re-survey after wall failure, Aug 2026
Initial establishment — 12 GCPs, GNSS static
Added 4 new prisms on eastern embankment
7. Confirm the upload
Once uploaded, the set's points appear as layers on maps at that site, grouped under the site and set. See How to work with reference points on your map in Birdi for what you can do with them there.
How versions work
Every upload is kept as a new version. Uploading a re-survey doesn't overwrite the previous one — it adds to the set's history.
This matters because:
You keep a record of what each point measured, each time it was surveyed.
The note you added on upload identifies each version.
The coordinate system carries forward from the previous version by default, so you're consistent unless you deliberately change it.
Note: A re-survey does not move points on maps that have already been built. Those maps keep the survey they were added from, so a map you've already measured against stays exactly as it was. New maps pick up the current version.
Downloading a set
You can download a reference set as a CSV, GeoJSON or produce a PDF report— useful for taking your control into QGIS, into a design package, or into a client deliverable.
Fixing upload errors
If a CSV doesn't upload, Birdi tells you the exact spreadsheet row that's wrong — so you can open your file, go to that row and fix it, rather than hunting through hundreds of points.
Common causes:
A missing or duplicated point ID — every point needs its own.
A blank coordinate field — easting, northing or elevation left empty.
Text in a number column — a stray note, a unit like "m", or a coordinate stored as text.
Extra rows below your data — totals, comments or notes at the bottom of the sheet.
Changed column headers — the template's headers need to stay as they are.
Tip: Fix the named row, re-save as CSV (not .xlsx), and upload again.
Best practice tips
Always start from the template. It prevents most upload problems before they happen.
Confirm the export coordinate system with your surveyor — in writing, not from memory.
Write a real note on every upload. Version history is only useful if you can tell the versions apart.
Keep point IDs stable across re-surveys. The same physical point should keep the same ID every time.
Upload one set per type. Keep GCPs and prisms in separate sets rather than combining them.
Download a GeoJSON copy after establishing a site, as a backup outside Birdi.
Related articles
How to use Sites in Birdi
How to work with reference points on your map in Birdi