I tried transferring points between different groups but what ever I did, I coudnt get actual heights.

I'm still not sure, what you are trying. Maybe, the following screenshot illustrates results that you are looking for. Here, point ST3 is treated as a reference point, having a known height of H = 500 m. The remaining points are points to be estimated, i.e., new points.

/Micha

When we go to the field, more often than not - we dont have heights of the benchmarks so we use custom height of 100,00 meters to check loop closure, and in the office we calculate data with actual heights.

I tried transferring points between different groups but what ever I did, I coudnt get actual heights.

Matija

When I insert reference points with actual height I am getting message "Error, the project contains uncombinable point typs, i.e. datum points as well as reference or stohastic points"

Yes, that is right. JAG3D supports four point types, i.e. reference points (variance-free points), stochastic points (point having some known uncertainties), new points (points to be estimated), and datum points (like new points but this points are used to solve the rank deficiency). A network can contain reference points, stochastic points, and new points (together); or datum points and new points (together).
So, you can not combine datum points and reference points; but new points and datum points, or even new points and reference/stochastic points.

What is best practice of calculation actaul heights of the points?

The point group type is interchangeable: right click at the tree item, and select the desired point type. To move points of a group, select the points in the point table, right click at the selected items in the table, and separate the points.

To move points from group to group, drag and drop is the best practice.

regards
Micha

I got same results - 3.8 mm closure of the loop which is ok.

https://ibb.co/0QDxZnB

My problem is that on the field we used some custom height for the reference point e.g. 0.00 while actual height differs.

When I insert reference points with actual height I am getting message "Error, the project contains uncombinable point typs, i.e. datum points as well as reference or stohastic points"

https://ibb.co/yWmMqhC

What is best practice of calculation actaul heights of the points?

Matija

okay, I import your GSI file to JAG3D and enabled the erroneous observation. The adjustment works fine. The loop error is about 4 mm. The results are presented in the "result table" of the points and the observation group, respectively.

I'm not sure about your problem. Can you provide further information?

regards
Micha