3

I am new to QGIS.

I have points uploaded to QGIS that were collected from a GPS, and I need to get elevations for each point (I don't trust the elevation estimations of my GPS).

What is the best way to do this?

Additionally, I realize I'll likely need an elevation raster, and I'm wondering if the Google terrain hybrid or Google satellite hybrid will work or if there's a better option?

2
  • Where in the world? – inc42 Dec 5 '19 at 18:19
  • As per the Tour there should be only one question asked per question. – PolyGeo Dec 6 '19 at 0:53
10

Basic steps to get elevation data in GPS points:

  1. Obtain an elevation raster for your area of interest. You'll need a DEM (Digital Elevation Model) raster, which is a raster of pure elevation data without any labels or additional features. (Google terrain is not an elevation raster, it's a combination of a "hillshade" or "shaded relief" raster with additional map features like roads, towns, labels, etc.)

  2. Add the elevation values to your point layer. You can use the Sample Raster Values processing algorithm (shown below) or the Point Sampling Tool plugin.

    enter image description here

2
  • Thanks so much for your detailed and easy to follow response! With some troubleshooting, I was able to get it to work, although I used the Point Sampling Tool instead of Sample Raster Values. – Brian Allen Dec 6 '19 at 2:25
  • Glad it helped. I added your suggestion of using the Point Sampling Tool plugin, which may be helpful to others with the same question. – csk Dec 6 '19 at 20:31
2
  • You'll need to search for a high resolution elevation raster for your area.
  • Open it in QGIS along with your GPS points.
  • Make a copy of your GPS points.
  • Use the 'Drape' tool in the processing toolbox to add z values to the points using the elevation raster.

Google terrain/satellite is not going to work. You will have to source a high resolution elevation raster. If you're in the US, check out USGS 3dep for elevation rasters. You will need 1m resolution if you want improved accuracy over your GPS device (which are usually around 10m).

1
  • Thanks, so much! This helped me figure it out! – Brian Allen Dec 6 '19 at 2:26

Not the answer you're looking for? Browse other questions tagged or ask your own question.