Virtual Marshal now offers checkpoints with directional control. It is standard practice to have timing controls setup in a road book rally where marshals operate the timing only if the entry on competitor is in the correct direction. This is useful in cases where the road book has been made that requires navigation around a “loop”. A normal checkpoint is triggered for recording time stamp when competitor reaches the geo-coordinates of the checkpoint irrespective of direction of entry.
Now you can create checkpoints with direction of entry too. The checkpoint will only trigger time stamping if the competitor reaches the geo-coordinates coming from the correct direction. You can do this by specifying the heading direction of the competitor while hitting the checkpoint. The system provides control within +/- 20º from the specified heading. Read the linked HowTo to understand how this is implemented while defining the checkpoint.
As an example suppose the route as defined by road book at a particular checkpoint is heading due east. By defining the checkpoint with heading 90º the time stamp is done only if the competitor enters from this heading only. Entering from any other direction will not trigger the time stamp.
The diagram on left shows checkpoint located just after the bend in the road with heading due north or 0º. If the competitor comes from opposite side on the route the time stamping will not be triggered.