I'll have to georeference (with a dgps) an archaeological site plan (2.7 km²) that's been done using local coordinate system (total station)

The actual GIS project in local coordinates contains a lot of data (vectors and rasters).

I'm looking for a way to avoid having to re-project each layer one by one but rather move all layers at once to absolute coordinates (UTM)

I was thinking about creating a custom CRS for all the local coordinate layers calculating the offset between the local and UTM coordinates. I've never done that before.

Do you think it's a good idea?

  • I may be being a bit daft but to me, it sounds like your suggested solution is reprojecting layers. Most GIS systems can display layers with different CRS and reproject on the fly and can batch reproject the layers as well if you want them store in a particular reference system.
    – RomaH
    Dec 31, 2021 at 21:46
  • I meant i wanted to avoid transforming local coordinates of every layer to UTM...
    – tonyduky
    Dec 31, 2021 at 22:28
  • Are you using any sfm software ?
    Dec 31, 2021 at 23:23
  • What software are you using?
    – Pointdump
    Dec 31, 2021 at 23:34
  • I'm using QGIS!
    – tonyduky
    Jan 1, 2022 at 10:50

1 Answer 1


A >>>Custom Affine Projection<<< would work well in QGIS. You'd need 3 Match-Up Points and a little work in Excel to get A0,A1,A2,B0,B1,and B2 numbers. Attached here is a typical spreadsheet: https://we.tl/t-f559a1AGSp

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