Furuno Marine Radar - Manual (Page 3)

1. Principles of Radar
What is Radar?
Radar is an acronym meaning RAdio Detecting And
Ranging. It is a device which measures not only the
time it takes for a pulsed signal to be reflected back
from an object but also its bearing relative to your
position. No other piece of marine electronics can give
you as much information about objects around your
own ship as Radar.
Present state of Radar:
Radar was developed during World War II. Today,
Radar is available for all classes of vessels including
small fishing vessels and pleasure craft. Many
pleasure boats may also have a color video sounder
(Fish Finder) or navigation device such as a GPS
receiver, but the single most important piece of
electronics is the Radar. No other gear can give you
the ability to spot a vessel coming at you out of the
fog, or tell you the location of the inlet to a harbor in
the pitch black of night.
For navigational safety, nothing beats Radar. While
your chart plotter may show you where everything
around you is supposed to be, only your Radar can
show you where everything is, including coastline
and navigation aids such as beacons or buoys, as well
as uncharted objects such as vessel traffic and other
obstructions.
About Furuno Radars:
The National Marine Electronics Association (NMEA)
annually recognizes its member marine electronics
manufacturers for superior products. Furuno annually
takes home the top award in several categories of
marine electronics equipment, and our Radars have
won the top prize every year since 1976. Furuno
has repeatedly won the coveted NMEA award for
Manufacturer of the Year - Support. These awards
make it clear that Furuno is the leading manufacturer
of Radar in terms of quality, reliability and after-
purchase support.
What Radar Can Do
Radar mainly functions as an anti-collision aid. It
also provides information about the whereabouts of
neighboring vessels, coastal outlines, etc.
Navigate in darkness and fog •
In fog or darkness, you may lose situational awareness
around your own ship because of poor or no visibility.
With Radar acting as your eyes, however, you have
the ability to monitor other ships’ movement under
these conditions.
Collision avoidance •
The guard alarm feature of every Furuno Radar alerts
you when targets enter a particular area, or own ship is
nearing a danger area. The alarm area can be forward
of own ship or a 360-degree circle around the vessel.
When Radar targets such as other ships, landmasses or
buoys enter the zone, an audible alarm sounds to alert
the operator.
Assess target movement •
The Echo Trail feature simulates target movement
in afterglow. It is useful for assessing the movement
of all targets relative to own ship. Some Radars have
the capability to show the true movement of targets,
providing increased navigational safety.
Determine own ships position •
Since Radar sees further than the naked eye, the
echoes from islands and landmasses can be used to
determine own ships’ position. When running near
land, you can use peninsulas and other targets whose
echoes show distinct contours on the display to
determine own ships’ position. Distant, tall mountains
or bridges may be similarly used provided they are
above the horizon
Navigate to specific location •
Fishing vessels and pleasure boats use Radar to
help them navigate to favorite fishing spots. When
navigating to a fishing spot, the forces of wind
and current can combine to throw the vessel off its
intended course. To remember your location if your
ship drifts, use the VRM and EBL to mark range and
bearing to nearby islands or peninsulas.
1 20
Mark Display:
Table 2 describes the marks commonly found on Furuno Radars.
Mark Appearance Description
Cursor + The cursor is controlled by operating the trackball, arrow keys or
omnipad. Its main function is to measure range and bearing to a
target, select AIS and ARPA targets, and set guard zones
Tuning Bar
+
The tuning bar shows receiver tuning state. Normally, a longer bar
indicates better tuning, however the length of the bar can vary
with range and number of targets.
Heading Mark
+
The heading mark shows own ships heading. With no gyro or flux-
gate compass the mark always points to zero degrees.
North Mark
+
This mark appears when a gyro or fluxgate compass is connected
to the Radar. The short dashed line always points to north.
Range Rings
+
Range rings provide an estimate of range to target. The interval
and number of rings may change with range.
VRM
+
Variable Range Marker. These marks appear on the display as
dashed circles. The length of the dash of the #2 VRM is longer
than that of the #1 VRM. They function to measure range to tar-
get.
EBL
+
Electronic Bearing Line. These marks appear on the display as
dashed lines. The length of the dash on the #2 EBL is longer than
that of the #1 EBL. They function to measure bearing to target.
Guard Zone
+
The guard zone defines an area which, when targets enter or leave
as per user settings, an audible alarm is triggered to alert the user
to the change.
AIS Target Display: ARPA Target Display: