Vessels in Hydromagic Dredging

In Hydromagic Dredging, a vessel object is used to represent a moving object like a dredger, barge or an excavator. A moving object can be configured as a vessel when it has been equipped with its own (GNSS) positioning system. When configuring dredging equipment, like a suction tube, cutter ladder or backhoe dredger, a vessel is used as a 'base' for this equipment.

Most of the time, for instance when you are configuring a trailing suction hopper dredger or cutter dredger, the dredging equipment is attached to the vessel, and you only have to configure the primary vessel. In the event that an excavator is placed on a barge, and both the barge and excavator are equipped with a positioning system, you have to configure both vessels to show them both in the navigation display. The images below show the difference between a single and dual vessel configuration:

Single vessel configuration. The dredging equipment is attached directly to the vessel or barge.

Dual vessel configuration. The excavator (red) has its own positioning system and can move around the barge (blue).

Configuring Vessels

To change the description, shape, color or other map display settings of a vessel, select "Preferences..." from the "Options" menu and select the "Dredging" tab. On this tab, you will find two buttons labeled "Primary Vessel..." and "Secondary Vessel...". Click the "Primary Vessel..." button to setup your vessel or barge. The "Secondary Vessel..." button can be used to setup, for example, an excavator which is on the barge.

NOTE: When two vessels are drawn in the display view despite of having only one vessel configured, just un-check all the data sources in the secondary vessel configuration screen to get rid of the second shape. See the "Selecting data sources" paragraph for more information.

Configure the vessel's from the "Dredging" tab.

Vessel Description

You can enter a vessel description in this field, for instance "Barge" or "Excavator". When configuring dredging equipment you can select the 'base' vessel by selecting this name. This is also the name which is displayed when including the vessel name in user defined log files. It is not allowed to use special characters here (except for spaces).

Enter a descriptive name for the vessel.

Selecting data sources (plugins)

By checking the check boxes, you can select which data sources (or plugin data) is used to set the vessel's position, heading, speed and motion (pitch and roll). When only one vessel needs to be configured, check all the boxes for the primary vessel and un-check all boxes in the secondary vessel's configuration. No need to select dredging sensors here, unless they provide draft, pitch or roll information.

Select the plugins used to position the selected vessel.

Heading sensor configuration

Some plugins for position can report both magnetic and true heading. For instance when data is coming in via a data combiner, or when a GNSS device contains a build-in magnetic compass. True heading is a heading calculated by movement, for instance by calculating heading between the current and previous position. When a magnetic compass or gyro has been installed, select the magnetic heading rather then a true heading, since a magnetic heading is also reliable when the vessel is not moving (or very moving slowly).

When using a RTK or GNSS heading sensor, it is sometimes needed to apply an additional offset. For instance when antenna's are placed next to each other instead of parallel to the vessels direction. In this case select a 90 or 270 degrees offset.

Select which heading sensor to use, either a compass or calculated heading.

Vessel shapes and color

In this section you must provide a shape file for the vessel. This can be the shape of a barge, vessel or excavator. When you are configuring an excavator on a barge, where both the excavator and barge are equipped with their own positioning system, you have to select the barge shape for the primary vessel and the excavator shape for the secondary. Click the "Browse..." button to select a vessel shape. Hydromagic ships with a collection of vessel shapes which are installed in the "Vessel" folder. By clicking the "Editor..." button you will launch the "Vessel Designer"", which can be used to draw or modify vessel shapes, or to import vessel shapes from AutoCAD DXF files.

You can select other vessel colors, for instance make sure the vessel contrasts with the background map (i.e. dark color when a street map or vector map is used, or yellow to improve visibility on a satellite image.

Select the vessel (top view) shape file to be used in the map view.

Distance rings

With the "Ring Count" option set to any value higher than zero, a set of rings will be drawn around the ship at fixed intervals. Use this function, for example, to see at a glance how far away the objects are from the boat. Another useful option is to set the interval to the distance between survey lines to get some sort of guidance. In addition to setting the distance between the rings and the number of rings, it is also possible to choose a drawing color for the rings, which is clearly visible against the background.

Distance rings can be used to see how far away objects are.

Distance rings around your GNSS position at a specified interval.

Course Line

The course line can be used to see where the vessel is going. Please note that the course line is indicating the correct heading only when the NMEA0183 output of your GPS or RTK receiver outputs this information and the vessel is moving. Alternatively, a compass or RTK heading sensor can be used to determine the correct course.

Check the show bearing option to display a course line on the map display.

Saving the settings

Click the "OK" button to save your changes. When more then one vessel needs to be displayed on the map display, just repeat this step for the secondary vessel by clicking the "Secondary Vessel..." button on the "Dredging" tab in the global preferences window.

"An example vessel configuration using the first NMEA0183 plugin for positioning.