Furuno 1830 User Manual

AIDS TO NAVIGATION
V'arious aids have been deveioped to oid tlie navigstor in jdontifyinc radar
targets.
RADAR 13EACONS
Radar beacons are transmitters operating in the marine frequency band
which produce distinctive indications on the radar displays of ships within
range of these bRaeons- There are two classea of beacons: racan and
ramark.
Racon
A racon is an omnidirectional transmitter which emits a distinctive signal
when triggered by ihe pulse from a ship's radar. Both range and bearing
to the target can be extracted from the signal. Because the beacon ' S Signal
travels at the same time as the echo arriving the ship's range to the target
can be determined. Since the signal will be received only when the scanner
is pointing directly at the beacon, bearing is shown as well as the range
and the vessel s position is thus determined. The range and bearing of the
racon signal is measured in exactly the same manner as a normal target pip-
The racon signal appears on the .display as either a radial line originating at
a point juGt beyond the radar beacon or as a Morse code Signal dispJayed
radially from just beyond the beacon. See Fig.49. Note that with the FT C
or IR Circuit switched on, the racon marker line may partially disappear.
(A) Coded Racon Signal (B) Racon Signal
Fig.49 Racon Signal Appearance
Ramark
A similar type of beacon is known as a ramark. It tranemits continuously on
a frequency constantly varying so as to sweep through the en Ure radar
band. The ramark signal appears as a radial line from the center of the
CRT. Tha radial line may be a eontinuous narrow line, a series of dashes
a sei'ica of Uots, or a series of dots and dashes. Fig.50 illustrates the
appearance of a ramark signal, as a dotted line, and as a dashed line.
Although the ramark flash shows only the bearing to the beacon, if the
ramark is mounted on the ooast and this can be also seen on the screen, a
fix can be obtained from the ramark.
(A) as a dotted line (13) as a dashed line
Fig.50 Ramark Signal Appearance
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Furuno 1830 Specifications

General

Brand	Furuno
Model	1830
Category	Marine Radar
Language	English