Division 4.14 Radar picture presentation and overlay

The radar image representation is mandatory for operation in the navigation mode.

The dimensions, resolution and attributes of the radar presentation shall fulfil the relevant radar requirements.

The radar picture shall not be degraded by other contents of the picture (see also point 4.3(c) of this Section).

Provided the functional requirements are fulfilled, overlaying of different information layers is permitted.

The overlay of information regarding the position and orientation of other vessels is only allowed when:

• the information is up-to-date (real-time), and

• the age of information does not exceed the maximum time out values provided in the first table in point 5.1(e) of Section 1. The symbols shall be marked as outdated, if the age of the information exceeds 30 seconds for moving vessels. The position information of the own vessel shall only be displayed when the position is detected by an on board subsystem and not if the position is received from a repeater station.

The overlaid information derived from tracking and tracing devices regarding the position and orientation of other vessels shall be faded out at a user-definable range. The activation of this feature and the selected range of the restricted area shall be indicated on the display.

Only if the heading of other vessels is available, the position and the orientation of those other vessels may be presented by:

• a directed triangle, or

• a true outline (to scale).

In all other cases a generic symbol shall be used (an octagon is recommended, a circle shall be used for inland applications only).

It shall be possible to switch off the chart and any other information layer and to display only the radar picture by one easily accessible control element or menu area.

If the quality and plausibility monitoring of the Inland ECDIS equipment detect that the chart cannot be oriented and/or positioned with the accuracy required by this Annex, an alarm shall be presented on the display and the chart shall be switched off automatically. If there is no radar signal, the information mode shall be displayed. In both cases a warning or an alarm shall be given. The switching shall always be possible by manual action.