ArborCAD - Accuracy
ArborCAD transmits most values as double precision values. However, for our purposes we are unlikely to need such accuracy and single point precision is normally adequate with the exception of the X/Y positions. These are READ from a manual plot as double precision and stored within ArborCAD as such.
The calculation of the RPA radius, its area and square side is rounded to 1 decimal place.
Calculation of multiple points along crown spreads are carried out using single precision.
If a canopy is being rotated then the rotated calculated dimension does lose some accuracy. I have so far calculated a tolerance of around +/- 1mm. You can check this accuracy by plotting a tree with rotate in force and measuring the dimension.
For example, the following image shows a tree with 0 degrees rotate and the same tree with +45 degree rotate. I measured the north dimension in both cases and are showing them highlighted in red in the text box. The first reading is the 6m value which is correct. The second is .5 of a millimetre out.
The calculation of the RPA radius, its area and square side is rounded to 1 decimal place.
Calculation of multiple points along crown spreads are carried out using single precision.
If a canopy is being rotated then the rotated calculated dimension does lose some accuracy. I have so far calculated a tolerance of around +/- 1mm. You can check this accuracy by plotting a tree with rotate in force and measuring the dimension.
For example, the following image shows a tree with 0 degrees rotate and the same tree with +45 degree rotate. I measured the north dimension in both cases and are showing them highlighted in red in the text box. The first reading is the 6m value which is correct. The second is .5 of a millimetre out.
