I am interested in preprocessing of network, like preliminary accuracy assessment.

You have to provide the design of the network, i.e., the (approximated) coordinates of the network. Moreover, you have to specify the observations between these coordinates. It is not mandatory to provide exact readings of the observations. You just have to specifiy the connections, i.e.,

P1 P2 0.00
P1 P3 0.00
P1 P4 0.00

In this example, the point P1 observs Point P2, P3, and P4. The observation values are arbitrary numbers.

Finally, you have to switch the estimation mode from L2-Norm (Least-Squares) to Simulation.

kind regards
Micha

P.S. I've moved you posting to a new thread.

Thanks for answer.

I am interested in preprocessing of network, like preliminary accuracy assessment. For example for 2D network with 4 points, if I have approximately coordinates of those 4 points and plan what I will measure in network like direction 1-4.., distance 1-2.. And I want to know how accurate and reliable my network will be.

I hope you understand now.

Thanks.