Smiths Kelvin Hughes Nucleus 3 5000 Series, System Handbook

Page: 61 / 510

STANDBY
175
This is the default condition of the radar at switch-on.
No radar information is displayed and the antenna is
not rotating.
176
The STANDBY menu screen is displayed, showing the
current status of the transceiver(s) (Master only).
There are three selectable options available to the operator:
GO TO MENUS, GO TO RUN and GO TO TEST (ATA and
ARPA fitted equipment display GO TO SIM instead of GO
TO TEST).
RUN
177 This is the active condition of the radar. The antenna is
rotating and the received radar information is
displayed on the screen. All functions are available for
selection.
CUR SOR PO SI TIONING
178
The cursor defaults to a particular (PARK) position
whenever the cursor is inactive outside the PPI for a
short time. The cursor parking position is an empty (black)
area of the screen close to the PPI and can be set either high
(35
°
position below GSR link box) or low (120
°
position,
above the cursor box). The cursor parking position (either
HIGH or LOW) can be set from the GO TO DEFAULT menu.
MAS TER GYRO HEAD ING & GYRO
WARN INGS
179 The master gyro heading is normally manually set to
the reading taken from the Ownship gyro repeater.
180
While the radar is switched on, Ownship heading is
tracked with the aid of a gyro compass. If the gyro
heading changes while the radar is switched off the radar
cannot keep track. Therefore when the radar is switched on
the gyro heading may be incorrect.
Gyro Alarm ON (Sea Mode)
181
This is the normal mode of operation for a ship borne
radar. On selecting GO TO RUN for the first time after
switch-on, the operator is requested to align the gyro
heading with Ownship heading before continuing to RUN
mode. Should a gyro fault be detected, a GYRO IS INVALID
warning box will immediately be displayed and the radar will
switch automatically to HEAD UP. A system warning will
also indicate that there is a gyro fault.
Gyro Alarm OFF (Land Mode)
182
This is the normal mode of operation for a land based
or fixed position radar where the heading is known and
will not change. On entering RUN mode for the first time after
switch-on, the cursor is positioned over the HDG box. A
warning box RADAR HAS BEEN OFF CHECK THE GYRO
is displayed, but the operator is not required to align the gyro
to Ownship heading. In the event of a gyro failure, or no gyro
being connected, no warnings are displayed, and the radar
will not switch automatically to HEAD UP.
SHORT/ME DIUM/LONG PULSE (MAS TER
ONLY)
183 A Master display controls the radar pulse length to be
transmitted depending on the range scale selected.
The operator may override the automatic settings shown
below:
Short Pulse (SP) - 0.25nm to 1.5nm ranges.
Medium Pulse (MP) - 3nm to 24nm ranges.
Long Pulse (LP) - 48nm and 96nm ranges.
184 The operator can select a pulse length either longer or
shorter than the automatic setting. If a shorter pulse
length is selected while using a range scale of 0.25nm to
1.5nm this will have no effect. However, the pulse length still
remains overridden and should the operator increase the
range scale to 3nm the automatic setting (MP) will be
overridden and SP will be used. Similarly, if a longer pulse
length is selected on 48nm or 96nm ranges, the pulse length
displayed will still be LP. Should the range scale be reduced
to 24nm then the automatic setting (MP) will be overridden
and LP will be used. While the pulse length is being
overridden the border of the pulse length box is red.
PER FOR MANCE MON I TOR
185
C h e c k s t h e o v e r a l l p e r f o r m a n c e o f t h e
transmitter/receiver system by displaying the radar
transmission PLUME and receiver response SUN at the
centre of the display. During installation, the radar
performance is measured to establish a performance
reference level, and written into the installation record.
TUNING & RE SPONSES
186
Tuning affects the signal received. A tuned receiver
will receive strong radar returns from its own
transmitter. Conversely a detuned receiver will receive very
weak or no radar returns at all from its own transmitter. This
feature is very useful for distinguishing between radar
returns and SART transmissions. A detuned receiver will still
receive SART transmissions even though its own
transmitter’s radar returns are not being received. This will
have the effect of removing all radar from the display except
SART responses.
Amdt. 5 1.25 July 03
KH 2020
Chap 1
GLOS SARY OF TERMS