[Therion] Standard deviation of estimated station coordinates from least-squares loop correction?

Xavier Pennec Xavier.Pennec at inria.fr
Sun Nov 6 11:58:27 CET 2011

I have a large graph of archaeological sites (medieval mines) connected 
by multiple surface surveys. The ensemble counts more than 120 sites 
("entrances") with 28km of survey including about 5000 stations 
connected by 500 legs with 187 loops and 297 connected components. Of 
course the surveys were done by different teams with different 
accuracies and the fixed points are GPS points with very different 
accuracy (from more than 30m to 1m for the professional GPS points by a 

I have heavily used the sd command to correctly weight the different 
measures in the least-squares loop correction estimation, which means 
that internally the system should have a pretty good idea of the 
accuracy of each station location. What I would like is to extract the 
standard deviation of the entrance locations when I export the 
coordinates in the cave-list export.
Does anybody has an idea of how to extract this standard deviation 


>  -------------------------
>  Xavier Pennec
>  Senior Research Scientist / Directeur de recherche
>  Asclepios project-team, INRIA Sophia-Antipolis
>  2004 Route des Lucioles, BP93
>  F-06902 Sophia-Antipolis Cedex, France
>  +33 4 92 38 76 64
>  +33 6 78 35 16 90
>  http://www-sop.inria.fr/asclepios/
>  -------------------------------

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