Emlid RS+ and RS2 vs Trimble = 60' difference

I have both the rs+ and RS 2, connected to NTRIP on a site. The surveyor is using a Trimble set up also connected to the same NTRIP service. both my units read the same 719.17 meters at a point. ( 2359.481 ft )
His Trimble set up reads about a 60’ higher elevation at the same point.
Could this be because we are using different EPSG codes? I would think that would not matter elevation from sea level should be the same.
He is using Nevada east US survey in ft.
Any Ideas?? THANKS

1 Like

Maybe elevations are Ellipsoid vs Geoid or E vs Local or G vs Local? Are you both localized on the same point network?

1 Like

I am not sure, same network for sure, there is only one here, but not sure if we were using same mount point, Id assume we were, being I was only 2 kilometres from it. How do you tell if your on ellipsoid or geoid?

1 Like

Emlid always shoots Ellipsoid unless you are using something other than Reachview that can run the Geoid. The Trimble may be localized or they may have a Geoid input. Do you know what the offsets are for your area? If you can give me a coord and I can pull it up?


I do not know the offsets, in the map I marked a couple coords

and Ellipsoid is Mean sea level correct?

Coords from a spot on the site

I just looked up the difference between the two, and that makes perfect scene how we could be getting different readings

Nope, see this link for a 101. Most notably check out the image at the top-right.

MSL is close to what you would get from a localized network based off of ground looped benchmarks, but it is still not the same.

Well, the offset is more than 60ft so we need to keep digging or there is another factor included.

The fact that you are saying 2300-2400ft vs the orthometric Google surface height of 2000-2100ft there is definitely something else being used by the NTRIP provider and also probably different datum being used between your two setups.

Good read! Thanks for the INFO, the 2300 - 2400 was a different example on a other site. on this site and coords I sent my elevation was 1943.1 ft. at the coords I provided above.

Ok, so that does match the ellipsoid for the most part. Theirs was 2,000ft +/-?

Oh, and nice model. Good job getting the enclosed area! This is the part that most commonly gets forgotten and when you look at it for the first time after processing you go “Aww man”. Parapets are a B.

1 Like

Yes so at 36.21025 and -115.14616 I was at 1943.1 ft elevation, and the site was dug up and built up over the lat year.

Thank you! harder than it looks, This was with the EVO 1, due to being to close to class D airspace with the DJI mavic. I had approval , but DJI would not fly

Ever walk a cell phone around a building taking geo tagged photos? I thought about it. but not sure how it would turn out with two different cameras

We had this issue as well.
Its ellipsoid elevation.
We had to export to a excel sheet then subtract the 50’ here.

Im using reach view, is there another app or devise you can use with the emlid? just curious…