I want to check the quality of digitized tracks. I suppose, that a track with a lot of regular vertices has got a good quality. And a track with less regular vertices has got a poor quality.
Maybe, I need something like a heat map for lines?
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Have you tried this? A QGIS plugin to count polylines / polygons vertices and add a new column storing the number of vertices per feature.
This could help sorting poor quality / good quality lines from your approach.
EDIT : if you prefer doing so in PostGIS directly, try st_NPoints function. The following query calculates the number of vertices in a new field. You just need to alter your table and add the new column.
SELECT st_NPoints(geom) FROM schema.table ;
Thinking of a way to visualise this.
I'm going by gut-feel here, so please forgive the vagueness :)
I'll assume that both tracks use the same CRS.
I assume that more detailed track is the 'baseline', and you want to measure how far away the other track is.
You could use PostGIS to connect each vertex on the baseline to the closest point on the less detailed line.
The length of each of these lines is the error for that vertex.
You could then sweep a 1D guassian kernel across the errors on the line to smooth out the error (e.g. using numpy/scipy). If you know Photoshop/GIMP, think "Guassian Blur", but on a line rather than a plane.
The smoothed error could then be used to style the width of the line (or the nodes).