Hello cavers, if one uses compass and backcompass in the centreline section Therion averages both data after inverting the backcompass value. The same is true for clino and backclino. Is there a way to give some kind of threshold to the survey data so Therion issues a warning if compass and (inverted) backcompass differ too much? Say the threshold is 2 degrees, the value for compass is 90 degrees and the backcompass reading 273 degrees. Now Therion should give a warning that the difference between both readings is 3 degrees. The same should be true for clino and backclino readings. The cherry on top would be if Therion could generate a list of stations / legs with differences greater than the threshold. With such kind of list it would be easy to locate legs which need a re-survey. Thanks, Roger