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We are a land survey company and are considering using QField to perform asset surveys for local government agencies.

Looking through the documentation it appears that QField can do most of what we require. However, it is critically important that we are able to record a z-value for the surveyed position of an asset/data point. So some questions:

  1. Does QField have the ability to record the z-value as well as the x and y values from the GPS position?
  2. If so, is it able to utilise a geoid file in order to determine the orthometric (rather than ellipsoidal) value for the recorded z-coordinate or is this something that would require post-processing?
  3. Given that the instrument we would be using would be attached to a survey pole, is it possible to apply a 'pole-height' in order to determine the actual elevation of the point at ground level?

This may be going beyond the scope of QField but the product we are currently using does all of these. However, it requires an always-on internet connection to function and some locations we work in do not allow for this.

  • Regarding your first question, in the screenshot in the GPS section of the user guide, you can see that the GPS position does have an "altitude" field (although in the screenshot the altitude value is n/a). qfield.org/docs/user-guide/index.html#gps – csk Nov 6 '19 at 20:11
  • Thanks csk. I didn't notice the Altitude field previously. Any idea why it's showing as n/a? Thanks again for your help. Will be interesting to see if anyone can help with the other 2 questions :) – Ben Nov 7 '19 at 5:26
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QField can record z value from NMEA sentence. Create a layer, then save as, select geometry type and flag include z-dimension.

I use it with an RTK GNSS. I collect point, lines (I have not try with area).

Create a new field in the attribute table called z and use an expression such as : Z($geometry) - (the height of pole) to calculate the z of ground.

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