24 electronic plotting aid (epa), Plotting a target, E-plot label target data – Furuno FR-2805 Series User Manual

Page 37: Vector

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1.24 Electronic Plotting Aid

(EPA)

A maximum 10 operator-selected targets
can be plotted electronically (manually)
to assess their motion trend. Five past po-
sitions can be displayed for each of the
plotted targets. If you enter a 7th plot on
a certain target, the oldest plot (past po-
sition) will be erased.

A vector appears when you enter a sec-
ond plot for the target and is updated each
time a new plot is entered. The vector
shows the target motion trend based on
its latest two plots.

Alphanumeric readouts at the upper right-
hand corner of the screen show range,
bearing, course, speed, CPA, TCPA, BCR
and BCT of the last-plotted target.

It should be noted that the true course and
true speed data are not updated in real
time.

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RNG 4.91NM
BRG 226.1

°

T

TRU CSE 263.3

°

T

TRU SPD 12.4KT

EPA

TRUE VECTOR 1 MIN WT

CPA 2.9NM TCPA *** MIN
BCR 8.9NM BCT 20MIN

E-plot label

Target
data

Vector

13:28

1

1

Note: EPA reguires own speed input (au-
tomatic or manual) and a compass sig-
nal. The vector and data are updated on
real time between plot entires. Note that
the plots will be lost when the compass
fails.

Plotting a target

To perform electronic plotting:

1. Place the cursor(+) on a target of in-

terest by operating the trackball.

2. Select a desired plot no. by pressing

one of the plot no. keys on the plotting
keypad.

3. Press the ACQ key on the operator

control panel, and the selected plot no.
is marked at the cursor position.

4. Watching the EPA time (TIM xx:xx)

shown at the upper right margin of the
screen, wait for at least 30 seconds.
Place the cursor (+) on the target at its
new location, select the same plot no.
for the target and press the ACQ key.

The plot no. moves to the new target
position and previous position is
marked by a small dot.

5. To acquire other targets, repeat the

above steps selecting different plot no.

Note: If a target once plotted is not plot-
ted again within 10 minutes, the warning
"UPDATE PLOT No" will appear on the
upper right margin of the screen and the
plot no. of the target flashes. If you want
to continue plotting this target, reacquire
it within five minutes. Otherwise, the tar-
get will be regarded as a "lost target" and
its plot no. and target data will be erased.
The larger the plotting interval, the less
accurate the plotted target data.

When a target has been plotted more than
once, the radar calculates its motion trend
and automatically displays a vector on the
target.

If you make entry of plot at the uninten-
tional position by mistake, re-enter the plot
no. at the intentional position within five
seconds. Then, a correction is accepted.

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