Base Height and RTK Elev


I am using 2 reach modules to survey points in the field. I am using one reach module as a base over a known point. The other reach module is on a rover pole. Both modules are up to date. NTRIP caster over 2 WiFi hotspots’.

During base set up, I enter the transformed coordinates as WGS84 and ellipsoid height into the base mode screen and enter the antenna height.

Most of the time, unless I am doing a large job, I do not start a new project, I simply pull my Lat Long and height from the Position box of the Status screen.

My question is:

  1. Does this height shown in the status-position box on the rover (during an accurate Fix) take into account the antenna height of the base? Of course without starting a new project under the survey tab it is not going to take into account the Rover antenna height, I am aware of that.

  2. Or with out starting a new project do I need to subtract the difference between the Base and Rover antenna heights?

  3. If it does not take into account the Base antenna height, should I add that to the ellipse height when I enter the ellipse height, and set the base antenna height to 0?

This is somewhat of a pressing issue. If anyone has any insight, I would be much obliged.

In the base section of the status window on the rover, the base shows the value with the added offset applied.
Rover will directly be affected by the offset set under base height. If you ad 10cm to base height, rover will display 10cm more if 10cm is added to base height.

If you set correct offset height to base and no offset on rover, the height value rover will output is at the phase nominel antenna height. For the Reach modul, that would be somewhere around the antenna bottom. So, no substraction is needed.

Bottom line, for rover to output correct height values for its intended usage, correct value should be applied to base.

Thank you for the reply.

If I am reading what you said correctly, in base setup, as long as I have the correct ellipsoidal height entered and the correct antenna offset height entered, then on the status screen during RTK FIX the rover position will be displaying the correct and actual rover antenna ellipsoid height. (Then an simple subtraction of the rover antenna height and geoid height should yield me the correct ortho elevation)

Spot on :blush::+1:

Fantastic! Thank you for the quick help. It is always much appreciated.

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