Q: How can I setup a dragged offset in NaviPac?
A: The dragged offset driver can be used for:
- 2D Positioning, if used without the compensate for depth option
- 3D Positioning, if used with the compensate for depth option of an object created in NaviPac config based on the offsets introduced, layback value and the depth from an echosounder.
(1) To 2D Positioning:
The screenshot shows a setup for the vehicle Vehicle dragged at surface that is being positioned in 2D from a Reference point - Towpoint with a layback of 50 m behind the Main Vessel.
(2) To 3D Positioning:
The screenshot shows a setup for the vehicle Vehicle dragged on the sea floor that needs to be positioned 3D by using the dragged offset driver from a reference point - Towpoint with a layback of 100 m behind the Main Vessel and compensated for depth below mother object.
The depth is being taken from the echosounder interfaced in the Main Vessel. The input is treated as cable out information and the layback is calculated using simple triangle (Pythagoras) calculation of depth and cable out.
The depth is being taken from the echosounder interfaced in the Main Vessel. The input is treated as cable out information and the layback is calculated using simple triangle (Pythagoras) calculation of depth and cable out.
The calculation of the positions for the two objects can be seen in the Helmsman display and in the Object monitor:
The layback can be adjusted in the Online while surveying by modifying the value in POI - User defined offsets view that can be accessed from Edit - POI (User defined offsets) or Alt+o :
