Electronic Plotting Aid (Epa) - Furuno FR1500 Mk3 Operator's Manual

1.25 Electronic Plotting Aid (EPA)

10 targets can be plotted electronically to assess their motion trend. Five past positions can be
displayed for each target. Working range of EPA is 0-48 nm irrespective of range scale. Note that
EPA is disabled when the ATA (ARP-17) is accommodated.
340 350
330
320
310
300
TAZ
290
280
270
260
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240
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200
190
Target data is shown in the data display area including range, bearing, course, speed, CPA and
TCPA of the last-plotted or selected target.
EPA SYMBOLS
○ Target plotted
□ Plotted target and the data being read
Flashing: Targets in Target Alarm Zone
△ Target on a collision course
Note: Plots will be lost when the compass or speed log fails.
1.25.1 Plotting a target
1. Place a cursor on a target of interest and press the
[PLOT SYMBOL] key. The target position changes
with a calculated speed and course every 1-2 seconds
by the auto follow-up feature, maintaining the
calculation origin at point (a). If option (7) TRACK is
ON, tracked positions are indicated by dots.
2. In more than 30 seconds but within 10 minutes, place the cursor on the latest calculated
position (b) and press the [ENTER/SELECT] key. The plot symbol changes from ○ to □. This
step is to identify the target on which you want the plotting data.
3. Place the cursor on the target within 5 seconds, maybe at a different location due to leeway at
(c), and press [PLOT SYMBOL] key. The vector will be drawn based on a trip between (a) and
(c). The target data is indicated in the text area to the right. Correction of plot position (c'), if
necessary, is possible within 5 seconds, to show the course made good and speed made good
(a-c').
4. Do the same for other targets (maximum 10). For targets already in auto follow-up, do steps 2
and 3.
000 010 020
030
040
1
050
060
3
1
070
080
2
090
100
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180
MAN 00:01
3 TRUE VECT
3Min WT
RNG 4.7NM
BRG 41.5°T
CSE 198.0°T WT
SPD 10.3K WT
CPA 0.9NM
TCPA 15:20
Target 2 is on a collision course as the extension of its
vector goes through the own ship position. Placing the
offset EBL will help for assessment. TCPA is counted
up to 99.59 min and beyond that it is indicated as
TCPA > 99.99 min.
-1.21-
+
(a) First plot position
+
(b) Latest calculated
position
(c) 2nd plot position
(c') Re-entry for correction