Dear Xavier, Thank you, this is exactly what I was looking for. I would imagine therefore a similar setting will allow small or no changes to be made to the az and the tape measurements when closing loops.
Something like: sd tape 1 cm sd azimuth 1 degree Cheers, Stelios On 05/03/2014 12:02, Xavier Pennec wrote: > Hi Stelios, > > if you believe that your clino measure is plus or minus 10 degrees (in > standard deviation, meaning that 95% of the measures at p/m 20 > degrees), then you state before your data: > sd clino 10 degrees > > You can put a higher value, for instance 1000 degrees or even more, > which means that all measurements (which will be between -90 and 90) > are in the flat part of the Gaussian, i.e. they have the same > probability. With such a sd, the (weighted) least-squares loop closure > algorithm will preferably change the clino measurement than any other > (provided that this allows closing the loops). Now therion will report > the closure error in meter and percentage error and the only > difference should be a decrease of error in X and Y and an increase in > Z (but usually little change on the norm of the 3D error). > > Hope that helps > > Xavier > > Le 04/03/2014 15:52, Stelios Zacharias a écrit : >> Dear all, >> >> I recall a discussion here about using a fairly broad sd value to >> allow loop closure when trying to transfer paper surveys into Therion >> - I may be misremembering. >> >> I recently surveyed a closed loop with a broken clinometer (spinning >> wildly with no fluid to damp the motion), so for each leg of the >> survey I have distance and azimouth accurately and slope as an >> approximation. How would I set up the sd (if indeed this is how I >> would do it) to close the loop and correct my approximate / estimated >> slopes? >> >> I look forward to hearing from you. >> Stelios Zacharias >> >> _______________________________________________ >> Therion mailing list >> Therion at speleo.sk >> http://mailman.speleo.sk/mailman/listinfo/therion >