I have some pdf maps that show airport noise contours. I need to get the area of noise from the map as a shape with coordinates that we can store in a database.(E.g., select 100 points on the noise area outline and store their coordinates.)

Here is a link to one of these maps:


I tried QGIS, add layer geospatial pdf. But attribute table doesn't have x, y coordinates.

I have also converted pdf to .DXF format and inserted it to ArcMap, but it doesn't have spatial reference.

  • Welcome to GIS SE! As a new user be sure to take the Tour. Here you are asking about two products that effectively makes this two questions and too broad for our focussed Q&A format. Use the edit button beneath your question to choose one and then tell us precisely what you tried with that and where you are stuck.
    – PolyGeo
    Commented Aug 31, 2016 at 7:05
  • This isn't two questions! The poster has just tried two ways of answering their own question, which should be commended!
    – Spacedman
    Commented Aug 31, 2016 at 7:24
  • So did you manage to load it into QGIS and plot it in the right place? When I try, I get it somewhere of the coast of Oman in the Indian Ocean, because something about the coordinate system isn't right.
    – Spacedman
    Commented Aug 31, 2016 at 7:37
  • @Spacedman thank you so much. I just inserted the pdf to QGIS and I see the contour lines. I even don't know how to plot it on base map. Since, when I open attribute table it doesn't have x, y coordinates,it only has one column "feature id".
    – nilou
    Commented Aug 31, 2016 at 7:49
  • 1
    @Spacedman The user has tried this in two products which is to be commended, but which product do they now want to ask about as a focussed question. The comments suggest it is QGIS so I'll edit it and re-open it as that.
    – PolyGeo
    Commented Aug 31, 2016 at 9:56

1 Answer 1


Load the PDF into QGIS, deselect or remove all the layers your aren't interested in, leaving you with just the contours. You should end up with something like this (using Quick Map Services' OSM base map):

contours over OSM

Note that the noise level of these contours is lost. Its an annotation in the PDF that has no geographic reference to the line, so does not load with the other layers from the PDF. So if you need the noise level for each line you need to add a new attribute to each contour line and enter it manually.

Then use Vector: Geometry Tools: Extract Nodes to create a Point shapefile of the nodes of the contours. Note these points form the line segments that make the contour lines. If you need more points on the lines then you need to densify the lines first, which is another step.

Then with the point layer loaded, it should now look like this:

lines and points

Now use Vector: Geometry Tools: Export/Add Geometry Columns. Decide what coordinate system you want the points in. Don't click the "save to a new shapefile" box, we're going to add them to the current map layer. Hit OK, then when its run hit Close.

Now your attribute table should have the X and Y coordinates:

enter image description here

in this case in the original coordinate system.

Saving the shapefile will give you a DBF file that you can read into Excel or other spreadsheet program for further processing and upload to your database...


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