[Qgis-user] Working with LIDAR data in QGIS

[Thayer Young]

Hi Dave, 
You will probably want to convert your LIDAR point cloud to a DEM raster. You can do that easily in Q.
It sounds like you may be looking for Topographic Prominence. You should look at the Wikipedia page for that to get a start. https://en.wikipedia.org/wiki/Topographic_prominence#Calculations_and_mathematics
There is an open source project called WinProm, you can see the code on Github and it looks like there are windows exe files too.https://github.com/edwardearl/winprom

You can also use the r.geomorphon tool in GRASS and then extract summits and depressions. GRASS can be run from within QGIS.https://grass.osgeo.org/grass78/manuals/r.geomorphon.html

There is likely a way to do it in python or R also, using one of the math or science packages, to find peaks and valleys in a 2d surface (Calculus). This is a well developed area of research, for example in biomedicine.


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Message: 1
Date: Thu, 2 Apr 2020 19:51:18 +0000
From: Dave Marshall <43carnaby at gmail.com>
To: qgis-user at lists.osgeo.org
Subject: [Qgis-user] Working with LIDAR data in QGIS
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    <CAOuYquPg8Yjj95g4yGmpKEVg06q53B-u=sO58MJBoNLR1R92sQ at mail.gmail.com>
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Hello,

I am relatively new to QGIS but have been able to generate some useful
images of LIDAR data with contours and shading. My need is to be able to
identify hill summits and preferably cols as well and to extract the
precise location and height of these positions. I'd like to know if it's
possible to extract the height data for a specific point using QGIS.

Thanks in advance for any help with this,

Dave Marshall
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