RTK Elevation reporting negative values

[julia.shestakova]

Hi @megalabhilo,

Alright, I see. Is 3.734 m a NAD83 or GEOID12B height of your base?

Emlid Flow requires ellipsoidal height to be set in the Base settings tab. All the height calculations on the rover depend on it. So we need to ensure you entered NAD83 height.

Actually, there is a way to place the base using orthometric height as well. But for that, you need to use the Choose from project option. Here is a post to learn more about it.

@megalabhilo

You bring up a good point, looking at the base station ellipsoidal height it shows that its nearly 2m higher (5.864 m) than some of the GCP points, and a few of those GCPs were recorded near/around the same area that the base station was located.

5.846 should be the sum of the base ellipsoidal height you entered and the antenna height over the point on the ground. Was your tripod height about 2 meters?