Smiths Kelvin Hughes Nucleus 3 5000 Series, System Handbook

Page: 70 / 510

PLOT MENU
Func tion
19 Provides a selection of functions; Past Plot ON/OFF
History (when ‘ON’ shows previous four plot positions)
Guard ring functions (switching ON/OFF and setting
Variable ring range and bearing) Deleting all plots and
Selecting Bow Crossing Range (BCR) or Closest Point of
Approach (CPA), and Labels allowing up to twenty targets to
be labelled numerically. The menu also contains END to
EXIT the PLOT menu.
Se lec tion
20 To select the Plot menu:
(1) H i g h l i g h t t h e P L O T b o x a n d p r e s s a n y
pushbutton. The Plot menu boxes appear in the
lower right-hand corner of the screen as shown
below.
(2) To change the ON/OFF state of the Plot History
facility, highlight the [HIST] box and press any
pushbutton.
(3) To delete all plots, Highlight the DEL ALL box.
Press any pushbutton to delete all plots. A warning
box is displayed; CLICK AGAIN NOW TO
CONFIRM ACTION.
(4) T o s e l e c t B o w C r o s s i n g R a n g e / T i m e
(BCR/BCT), the displayed target information is
changed. BCR/BCT data replaces CPA/TCPA.
(5) To change Target Data Function:
(a) Highlight the BCR/CPA box.
(b) Press any pushbutton to change the functions
CPA/TCPA and BCR/BCT.
CPA/TCPA is replaced with . . .
BCR/BCT readings in the ranges of :
-99.9 to +99.9nm
—.- after +/-99.5min
(6) To enable the Labels facility: position the cursor
o v e r t h e L A B E L S b o x a n d o p e r a t e a n y
pushbutton. The box outline highlights in red - the
LABELS facility is enabled. To disable this facility
position the cursor over the LABELS box and
operate any pushbutton.
(7) To leave the Plot menu, highlight the END box
and press any pushbutton.
Guard Zones
21 Two Guard Zones are available, one Fixed and the
other Variable, each zone is preset to 0.5nm wide. The
guard zones operate by directly ‘Searching’ the screen for
targets inside the zones.
When in use, the following
points are to be remembered :
(1) Radar Controls GAIN/SEA/RAIN, Correlation,
Pulse Lengths and Video Enhance affect the
amount of video on the screen and may be used to
optimise the ‘Searching ‘ of the zones (i.e. False
alarm rate should be reduced).
(2) If the range in use is less than the guard zones
range then the zones do not operate until the
range scale is increased.
(3) The Operator must note that ‘WHAT HE SEES ON
THE SCREEN IS WHAT THE GUARD ZONES
SEE’.
Fixed Guard Zone
22 The Fixed guard zone is preset between 5.5nm and
6nm (i.e. Outside the sea clutter field).
23
To activate the Fixed guard zone, select the [GUARD]
function in the PLOT menu. Press any pushbutton and
the Fixed and Variable guard zones appear on the screen at
5.5nm and 6nm respectively. Press the right-hand
pushbutton (Vari OFF) to turn off the variable guard zone.
Press the left-hand pushbutton (Zones Active) to activate the
guard zones. The centre pushbutton (Guards OFF) deletes
fixed and variable rings.
NOTE:
(1) Subsequent operation of the pushbutton turns the Fixed
guard zone off, and the guard zone ring is cancelled.
(2) Targets are acquired and marked with a symbol when
the Guard Zone is activated, further plotting is to be carried
out manually by means of SELECT and ACQ (Acquire) for
each target.
Vari able Guard Zone
24 Activation of the Variable Ring guard zone is automatic
when the Fixed guard ring is turned on. The Variable
Ring guard zone appears on the screen at the default
initialisation range of 7nm to 7.5nm.
25 The Variable Ring guard zone can be positioned at any
range from 0.5nm out to 40nm.
26 To change the Variable guard ring range, move the
trackerball to anywhere on the ring (not at the ends)
and press the SELECT pushbutton. Movement of the
trackerball then changes the range. Pressing SELECT again
fixes the new range.
KH 2020
Chap 2a
Amdt 5 2a.3 July 03
CD-2072
HIST
END
GUARD
DEL ALL
BCR/
CPA
LABELS
OFF
Plot Menu (EPA System)