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Excuse me if this is a stupid question, but I've honestly tried to find the answer in a few threads here on SE, and I cannot seem to follow the suggested steps correctly.

  1. Project is in EPSG:3857 (WGS 84 / Pseudo-Mercator)
  2. BaseMap (OpenStreetMap) layer is set to EPSG:3857
  3. Vector data has been imported from CSV, and has Lat/Long coordinates, set to EPSG:3857.

The layer appears right in the middle of the map, around 0,0 obviously.

Why is this, what am I doing wrong?

Vector data layer properties

OSM Basemap with vector data shown

nmtoken
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Jack Diss
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    You've discovered Null Island! There's actually a huge difference between WGS84 decimal degrees (4326) and WGS84 Web Mercator (3857), and you cannot try to equate them without the degree values being plotted at meters at the Web Mercator origin at the Prime Meridian/Equator intersection off the southern coast of West Africa. Do not set the CRS of 4326 data to 3857 (use 4326 instead) and project-on-the-fly should handle the rest. – Vince Nov 04 '19 at 15:00

1 Answers1

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You have to import CSV file as EPSG:4326 (seems like it from the extent). QGIS will do on the fly reprojection into 3857. Don't forget to put Lat as Y and Lon as X.

enter image description here

Right now you are saying that your layer is in the 3857 projection. Which I guess is not true, right? Web mercator EPSG 3857 has coordinates from -20048966.10 to 20048966.10 and you have LatLon around 0 and 50.

It might be enough to right click the layer and set projection of the layer to 4326 (this might not work, if you put Lat as X and Lon as Y:

enter image description here

Jan Doležal
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  • Hi Jan, thank you. When you say 'the extent' why do I need to use WGS 4326, and not WGS (Pseudo Mercator) 3857? – Jack Diss Nov 04 '19 at 15:01
  • @JackDiss well, the input layer is in WGS84 (4326) which is not the same as Web Mercator (3857), that is why you have to tell QGIS that the input layer is in that coordinates, or it does not know how to reproject it. WGS is Geographic coordinate system Lat/Lon and Web mercator is projected system X/Y https://en.wikipedia.org/wiki/Web_Mercator_projection – Jan Doležal Nov 04 '19 at 15:04
  • Thanks Jan, I've now solved it by changing the X to Longitude and Y to Latitude... Could you explain this, as I had always understood the X axis as latitude.. – Jack Diss Nov 04 '19 at 15:11
  • Take it this way. Lat is from bottom to top (-90,+90) Lon is from left to right (-180, 180). Lat > top/bottom == Y, Lon > left/right = X :) – Jan Doležal Nov 04 '19 at 15:14
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    You've been really helpful Jan, thanks very much! I've accepted that answer. – Jack Diss Nov 04 '19 at 15:18