Extracting GPS coordinates from digitised point data (QGIS)

[tvr...@st-andrews.ac.uk]

I have a georeferenced paper map within QGIS containing a load of animal locations. I've digitised these locations as point data but want to be able to extract their exact coordinates (within BNG) without having to hover over each point with the mouse. Is this possible?


Thank you,

Toby

[GIS in Ecology]

Hi Toby,

 

If you wish to extract the coordinates of your points in QGIS, you would use the EXPORT/ADD GEOMETRY COLUMNS tool (click on VECTOR on the main menu bar and select GEOMETRY TOOLS> EXPORT/ADD GEOMETRY COLUMNS).

 

To use this tool, first make sure that your GIS project is set to use the British National Grid projection, and that your data layer is also in this projection (if it is not, you will need to transform it into this projection before you start - let me know if you don't know how to do this and I can explain).

 

Once everything is in the right projection, you can open the tool by clicking on VECTOR on the main menu bar and select GEOMETRY TOOLS> EXPORT/ADD GEOMETRY COLUMNS. Once the tool windo opens, select your point data layer in the INPUT VECTOR LAYER section, and then select either LAYER CRS or PROJECT CRS in the CALCULATE USING section. Finally, you need to decide if you want to add the information to your original data layer (as new columns) or make a new data layer. Once this has all been set, click on the OK button. It may, at first, appear as if nothing has happened. If this is the case, don't worry, simply click CLOSE to close the tool window.  Now right click on the name of your original point data layer (or the new one you created depending on exactly what sewttings you used) in the TABLE OF CONTENTS window and select OPEN ATTRIBUTE TABLE. This will open the attribute table and you will see the new columns it has created. Examine these values and make sure that they look like they are right for the part of the world where your data come from, and for the projection/coordinate system you are using. If you are happy with them, then you can close the table,

 

If you think that they are not right, do back and check your projections for your GIS project, and for your point data layer, and then repeat.

 

I hope this helps, and if it doesn't just let me know and I can look into this further.

 

All the best,

 

Colin