Coordinates and control points

The coordinate reference system is the first thing to set on a project, because every eastings-and-northings import after it is converted through the CRS you chose. Control points are the surveyed marks that tie your data to the ground. Both live in the project’s Spatial tab.

Before you start

Only organisation admins can change a project’s CRS. Deleting an individual control point needs the Delete control points permission. Control points are included from the Starter plan.

Steps

1. Open the Spatial tab and find the CRS chip

   Open the project and select Spatial. The chip on the left of the toolbar is labelled CRS; until a system is set it reads No coordinate system with a warning-coloured globe. Click it.

2. Set the coordinate system

   The popover is headed Coordinate System and shows No coordinate system set. Select Set CRS, open the list — placeholder Select coordinate system… — and pick one. Each option reads as name then code, for example OSGB36 / British National Grid (EPSG:27700). Set the Effective Date and select Save.

3. Attach a site calibration, if you have one

   Choosing Local Coordinate System (LOCAL) adds a JXL File field with the dropzone hint Click or drag a .jxl file here. Drop the site calibration in. If it contains control points, the checkbox Import N control points appears — tick it and they land in the project as part of the same save, listed with Name, Code, Easting, Northing and Elev in a preview table first.

4. Import control points from a CSV

   In the Layers rail, find the Control points group and use its add button, Import control points. The dialog is Import Control Points: Upload a CSV file, select the coordinate system, and map columns. Select Choose File — .csv and .txt are accepted — and tick Skip first row if your export has a header.

5. Say which coordinate system the file is in

   Set Coordinate System to Project CRS (which names the project’s own system beside it) or override it with OSGB36 / British National Grid, OSGB36 / OSTN15, OSGB36 / OSTN02 or WGS 84 (Lat/Lon). Choosing WGS 84 shows the reminder Coordinates must be in decimal degrees.

6. Map the columns and import

   Under Column Mapping, set each column to Name, Easting, Northing, Elevation, Description, Code or Skip. The preset buttons — PENZC, PNEZC, PENZ, PENZCD — do this in one click for common export layouts. Check the Preview, then select Import N Points. Name, Easting and Northing must all be mapped or the import refuses.

Options

Record where the points came from

The import dialog carries three provenance fields: Provided By, Date Received and Description. They show up again in the inspector as Provided by and Received, and in the set’s Details dialog alongside Uploaded By and Uploaded. Fill them in — a set with no stated origin is hard to defend later.

Add a point by hand

Select a set, then Add point. The Add Control Point dialog takes Name, Easting, Northing, Elevation, a Type of Control Point or Datum, and Description (optional). There are no latitude and longitude inputs — those are derived by conversion from the eastings and northings.

Manage a set

Selecting a set opens the inspector. Star it with Make primary. Mark a set Do not use when it is superseded but you want the record kept. Details opens the full metadata, including Convert Coordinates if you need to re-run the conversion under a different CRS. CSV downloads the set — the original uploaded file if it is still there, otherwise a generated file with the header Name,Easting,Northing,Elevation,Code,Description.

Which systems appear in the list

The CRS list is drawn from your organisation’s allow-list, set under Coordinate reference systems in organisation settings — Which coordinate systems projects in this org can pick from. If nothing has been added, the full master list is offered: WGS 84, OSGB36 / British National Grid, OSTN15, OSTN02 and Local Coordinate System. Editing that allow-list needs the Manage org settings permission.

What happens next

Control points draw on both the project and job spatial maps, and survey points can be lifted into the project’s control-point list from a survey. Jobs read the project’s CRS — from a job, the CRS panel offers only Edit in project.

Troubleshooting

Changing the CRS asks for confirmation. It should. The dialog Change Coordinate System? warns that Changing the coordinate reference system can affect survey data and spatial calculations for this project. Existing conversions do not re-run themselves; use Convert Coordinates on a set to redo one deliberately.

Delete is refused. Deleting a point needs the Delete control points permission; without it you get You don’t have permission to delete control points. The Manager and Surveyor role templates include it, Viewer does not.

Points arrived in the wrong place. The file was almost certainly read under the wrong coordinate system. Open the set’s Details and use Convert Coordinates to re-run it, or delete the set and re-import with the right Coordinate System.

A set landed under Ungrouped points. Those are points imported before sets existed: Import or add them into a set to give them provenance and a CRS.