Which Way Is Up? – Plan View Rotation

Chesapeake Times, Vol 5 | April 2021

North-up has until recently been the only plan view orientation available in SonarWiz. Views other than the main plan view – the external helm display and the 3D viewer – have been able to orient to the current survey line or vessel, but the plan view has always remained north-up.

A recent release of SonarWiz includes as a new feature the ability to rotate the main plan view itself. This allows for easy orientation to a user-specified heading, the current steering line, or actual vessel heading. Real-time collection benefits the most from this; SonarWiz can now make it easier to follow planned lines and ensure good coverage without the overhead of managing other programs and windows, especially with the help of the L/R steering indicator:

In the 2D Map Display section of the View ribbon tab, note the additions of a Compass Rose checkbox and an Orientation drop-down:

The Compass Rose checkbox in the ribbon displays a compass rose in the top right corner of the plan view to make its orientation apparent. It’s a four-pointed design with one red point indicating zero, with a textual indicator in the center denoting the heading at the top of the screen. Tick marks are arranged at 30 degree intervals.

The Orientation drop-down offers quick switching between three modes: user-specified, ship up, and line up. Switching into any of these modes directly in the drop-down will switch to that mode, and apply it if/when it becomes applicable.

User-specified at 315 degrees:

Oriented to the currently-selected steering line:

Oriented to a vessel recording some simulated bathymetry data:

User-specified mode is applied by default at program startup with a zero heading, replicating north-up. Switching into this mode from either of the other two via the drop-down will snap the plan view back to its prior user-specified orientation. Ship-up and line-up orient the plan view to the currently active vessel or currently-selected steering survey line, if any.

The Settings entry at the bottom of the Orientation menu will allow for providing parameters to the user-specified and ship-up modes. User-specified mode allows for entering a heading value to place at the top of the plan view. Ship-up mode offers a threshold; incoming navigation headings differing from the current plan view orientation by more than this threshold will trigger a rotation.


– Jonathan Fleetwood, Engineer