Why do we persist with this ridiculous pattern of arbitrary (read stupid) rotation conventions? When we are taught at Uni to take a measurement of a plane with an internal pitching lineation we take a strike and dip or a dip and dip direction, and then measure the pitch in the plane as a rotation from the horizontal.
Then you can always go to Isatis with its flash build you own (I know most software programs have this option but not many use it) with a bunch of rotations called Fred, Fred2, Datamine, Datamine2 (both of which do not seem to match Datamines own), GSLIB - which I am sure is correct because I have never been able to get the GSLIB rotation right in my own mind - took me years to workout the major axis is the X axis and not the Y axis like most other programs! They even have a Leapfrog rotation now - which somehow never seems to give me the rotation I get out of Leapfrog! Then there is Isatis Mathematical - a real do ya head innerer?
I reviewed another estimate recently where you could see they simply screwed up, used a +ve rotation rather than a -ve one the Y axis rotation and pushed the search 90 degrees in the wrong direction (and then obviously never bothered looking at the blocks in 3D!). Conclusion was either the original author had poor record keeping skills, didn't have a clue what they were doing or I was simply unable to understand the intricacies of Datamine's search rotation rules (would not be a bad bet to place money on the latter!). And when I tried to create a search ellipse to match these rotations I simply could not get one to match the smoothing trend I could see in the grade estimate (which certainly didn't match the rotations in the paperwork!). But it is different again in Datamine where it seems you simply make it up as you go along! I reviewed a model done using Datamine where every domain used a different rotation convention (Dom1 = 3:2:1, Dom 2 = 3:1:3, Dom 3 = 3:1:2). If you use Surpac, and if someone gives you a model estimated using Vulcan the rotations discussed in the paperwork (assuming the author got it correct in the first place) are different. I might not be the sharpest tool in the shed and I like to think I am not stupid but working out what rotation has been used to estimate a resource sometimes does my head in. Every company seems to want to use a unique, individual method of defining the rotation and then provide a set of instructions guaranteed to confuse anyone who attempts to read them.