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I'm trying to measure the distance between some coordinate points along a road line from an OpenStreetMap source map, I am using QGIS 2.4.0.

My problem is to find a way to measure these distances between points on a irregular line like a road with some precision.

I got some points from a GPS took along some of the roads to verify if the precision is acceptable and help with the measurements. Also I have a table with another points in kilometers without coordinates system reference and I have to create a relation between all these points to relate the distance.

I was able to find some tools that give me a measurement in a straight line and It bring me a lot of imprecisions with kilometer points.

Germán Carrillo
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Sérgio Ferreira
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1 Answers1

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That's a very nice use case for Linear Referencing tools.

Have a look at my answer to this post: QGIS Linear Referencing.

There I explain the capabilities of the QGIS LRS plugin.

That should help you get started.

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Germán Carrillo
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  • Good one! One more question: I have some segments for the same road that implicates different ids for each part of a road. The plugin understand It or should I find a way to create one ID for the same road? In that case have you a clue? Thanks for the help @gcarrillo !!! – Sérgio Ferreira Feb 10 '15 at 19:58
  • If all segments are part of the same road, I would do a UNION of them all, so that they are represented by a single line. @SérgioFerreira Please see http://gis.stackexchange.com/tour The way you reward people who answer your question is i) upvoting the question if it is useful for you, and ii) marking the answer as accepted if it solves (or helps you solve) the problem. – Germán Carrillo Feb 10 '15 at 23:31
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    Done It!!! Do you know if is possible create new milestones between known points I Got using LRS? – Sérgio Ferreira Feb 11 '15 at 00:20
  • Not sure what do you mean by milestones between known points. Please check again this post: http://gis.stackexchange.com/questions/130307/qgis-linear-referencing/130331#130331 and the documentation of the plugin, if you don't find there what you want, chances are it's not supported. However, if you can provide much more detail for your new question, feel free to open a new question about that. – Germán Carrillo Feb 11 '15 at 01:22
  • Example: I have a shapefile with coordinate GPS points of kilometers 32, 64 and 93. I don't have the intermediate points between these km values. So, I have to make a projection of the milestones (kilometer stones) on the map between those values I got as road references to find the right place of events along the road that I'm looking for. @gcarrillo – Sérgio Ferreira Feb 11 '15 at 01:46
  • So you need to create points along the line separated by 1Km? In that case, use the QChainage plugin. I don't have any experience using it, just know it does that. – Germán Carrillo Feb 11 '15 at 02:00
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    Yeap, also is what I need. Thanks to point It to me! @gcarrillo – Sérgio Ferreira Feb 11 '15 at 02:12