This is an advanced feature, don't use it if you aren't sure.
When this function is actived in toolbar () the position reading from GPS is moved orthogonally the desired distance (warning with the sense of the walk!!).
This feature is useful when the perimeter of study is to a certain distance from the walking path (par example, by car)
In the figure, the blue contour was measured without this function and the red with an offset of 3 meters to left (anticlockwise sense)
The use of this function may cause strange corners. If this happened, manually delete the necessary points.