User Chart Control; Introduction; Objects Of User Charts - Furuno FEA-2807 Operator's Manual

15. User Chart Control

15.1

Introduction

User charts are simple overlay charts that the operator makes for his own purposes. They can be displayed on both
the radar display and the electronic chart. These charts are intended for highlighting safety-related items like
position of important navigation marks, safe area for the ship, etc. User charts areas can be used to activate alerts
and indications based on operator-defined danger symbols, lines and areas. When route or estimated ship's position
is going to cross a user chart symbol, line or area that is defined as a dangerous one, an alert or indication is
generated by the system. For details about chart alerts, see Chapter 11 "Chart Alerts".
A user chart consists of points, lines and letter/number, symbols, etc. The number of elements for a user chart is
limited as follows:
•
200 Points
•
2000 Lines
•
1000 Symbols (alphanumerics)
•
50 Areas; an area can have 20 corner points.
The user chart is displayed on the radar display and its position and shape are based on the ship's actual position.
When your ship is moving in the area covered by the user chart, the elements of the user chart are superimposed on
the radar overlay, with max. 80 nearest elements of drawing point displayed. The user charts can also be shown on
the ECDIS display. In this way the radar display can be kept as "clean" as possible for radar target detection.
15.1.1

Objects of user charts

Below is a description of the objects used in a user chart.
•
Line: You can define six different types of lines. Lines can be used in chart alert calculation and/or display on
the radar:
•
Navigation lines: Displayed on both radar overlay and ECDIS. Navigation lines are reference lines for
coastline.
•
Coastline: Displayed on the ECDIS display only. A coastal line is usually a well-defined (by chart
digitizer) multi-segment line showing a coastline. The operator is able to create this type of line in case
there is no suitable chart available over desired area in ARCS or S57 format.
•
Depth contour: Displayed on the ECDIS display only. A depth line shows the selected depth levels. The
operator is able to create this type of line in case there is no suitable chart available over desired area in
ARCS or S57 format.
•
Route line: Displayed on both radar overlay and ECDIS. Route lines are zones for anchoring, traffic
separation lines, etc.
•
NMT (Not More Than) line, NLT (Not Less Than) line: A danger bearing or clearing line. Single line
with an arrowhead directed at the base of a charted object. Displayed on ECDIS only.
•
Area: User can define closed areas that the system can use to detect safe water areas. If route or estimated ship
position is going to cross the area, the system generates a warning to the operator. These areas can be used to
specify safe areas as defined by the master of the ship or by the policy of the ship's owner. They are always
available regardless of the type of chart material used.
•
Symbols: User selectable symbols can be displayed on both displays or on the ECDIS display only. Symbols
are used to indicate buoys, lighthouses, fixed targets, wrecks, etc. Symbols can be used in chart alert
calculation.
•
Tidals: Displayed on the ECDIS display only. Tidals can be used to make own notes about tides at operator-
defined points.
•
Points: It doesn't itself have a symbol on the radar screen, but it is a very important element of a user chart. For
details, see section 15.2 "What is a User Chart Point and How is it Used?"
15-1