Calibration of Vertex IV

Lesson 21: How to calibrate a Vertex IV for tree height and distance measurement?
#unigöttingen
#forestinventory
#forestmensuration

[@naughtysecretaryyy]

are you sure for the transponder it's the back end and not the front end that should be used for calibration? because when using the vertex on the sound mirror the front end emits the ultrasound which is then reflected circularly, otherwise the depth of the transponder itself would need to be substracted internally when measuring distance to a middle point. plus the way i learned how to measure tree heights for example, you would have to hold the transponder to the side of the tree you want to measure, at the point where the center of the tree is. when putting the transponder on the surface of the tree in your own direction you have a fairly big distance deviation the bigger the tree gets. loving the channel though, i'm happy to learn if i'm wrong!

[@forestinventory]

The first one is a valid point, it depends what you intend to measure. If you use the Transponder to get distances to the plot center (on the mirror), I would calibrate to the pole to compensate the 3.5cm. The second point (tree height) is not relevant from my point of view. You like to measure a baseline of a right triangle that you never get perfect on a tree. The small difference between stem axis and front side is not of relevance here and far below all the other errors you do anyway. The small hook is to fix it on the bark, if you measure to the stem axis, you would need a second person...

[@naughtysecretaryyy]

@@forestinventory yes, the point with needing a second person stands valid, I was looking at it from my experience in a forest engineer office, where we would almost always work in teams of two. so technically it would be more accurate to hold the transponder next to the tree, however as you'll probably never be able to aim for the exact top of the tree, that few centimeters might not make the biggest difference. thanks for responding this quickly!