In the real world:
I have a underground pipeline which has just been laid.
A surveyor has come along and taken shots to the top-of-pipe at each join along that whole pipeline.
In GIS:
I have brought those surveyed points into QGIS: each point has an elevation.
I have created a polyline representing the pipeline, using the points as nodes, starting at chainage 00 and continuing until the end of the pipeline.
Task:
I want to see a longitudinal section of the pipeline, by selecting a particular polyline at a time.
Constraints:
- I don't want to rasterise/rasterize anything.
- I don't want to use a DEM.
- I DO want to use the elevation on the points, along with the pipeline polyline to create my longitudinal section.
Experimentation:
I have tried all (or just about all) QGIS plug-ins that create a longitudinal section, with no overall joy.
- I think I want a scatter-plot of Chainage (x-axis) and Elevation (y-axis).
- I think I need the ability to change the X:Y ratio of the chart so it doesn't matter if the pipeline is 10 metres long or 10 kilometres long and - I can show some vertical exaggeration.
Is there a simple way to do this without the answer being "...you can just write a Python script..."?