On Sun, Jan 01, 2012 at 01:50:35PM +1300, Bruce wrote: > At first look it seems like this might be a desired response from Therion. > How can two stations with specified and differing co-ordinates be 'equal'? > > My assumption was that the standard errors give the actual position of the > station a degree of uncertainty or 'fuzzyness', and that by equating two > such stations they would be 'averaged out' in a similar way to loop closures > or two fixed stations connected by a survey network.
That's how Survex handles this case. It'll only give an error if you omit the standard deviations (the "4 4 12" in this case) from both fixed points and the coordinates aren't the same). Cheers, Olly