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Author Topic: How do I extract DEM elevations at specific coordinates?  (Read 1802 times)

WSurvey

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How do I extract DEM elevations at specific coordinates?
« on: June 18, 2019, 01:35:24 PM »
Hello,

Given a text  file of E,N or X,Y or Lat,Long horizontal coordinates, is there any way to automatically extract the DEM elevations at these locations? Perhaps a way to import points and set them on the DEM and export again?

Cheers

toxicmag

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Re: How do I extract DEM elevations at specific coordinates?
« Reply #1 on: June 18, 2019, 02:08:15 PM »
Most GIS solutions can do this easily.

I would recomment QGIS and its point sampling tool. You could even import your points from txt/csv first in a new shape layer and then apply these point coordinates to a DEM (or several different DEMs for comparison) and you will get a table of all the heights extracted.

Cheers
Alex
#multirotor #VTOL #Trinity #Quantum-Systems #a6000 #a7R #RedEdge #ALTUM #RX1II

WSurvey

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Re: How do I extract DEM elevations at specific coordinates?
« Reply #2 on: June 18, 2019, 02:19:21 PM »
Thank you Alex. Failing an Agisoft solution I will use the QGIS plugin you mention.

toxicmag

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Re: How do I extract DEM elevations at specific coordinates?
« Reply #3 on: June 18, 2019, 02:32:58 PM »
You could import your points as markers, but this only works as long as there is an altitude available.   ;D
« Last Edit: June 18, 2019, 02:34:35 PM by toxicmag »
#multirotor #VTOL #Trinity #Quantum-Systems #a6000 #a7R #RedEdge #ALTUM #RX1II

Alexey Pasumansky

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Re: How do I extract DEM elevations at specific coordinates?
« Reply #4 on: June 18, 2019, 02:52:00 PM »
Hello WSurvey,

In Metashape you can solve this task by importing point shapes to a separate shape layer, then in the Ortho view mode select all shapes of the imported layer, use Update Altitudes option for the selection and then export the shapes.

Update altitude would write Z value of the DEM under XY coordinates for every shape vertex.
Best regards,
Alexey Pasumansky,
Agisoft LLC

WSurvey

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Re: How do I extract DEM elevations at specific coordinates?
« Reply #5 on: June 18, 2019, 06:03:06 PM »
Hello WSurvey,

In Metashape you can solve this task by importing point shapes to a separate shape layer, then in the Ortho view mode select all shapes of the imported layer, use Update Altitudes option for the selection and then export the shapes.

Update altitude would write Z value of the DEM under XY coordinates for every shape vertex.

Thank you Alexey.