Filter
Top Products
3-6
Radar bandwidth
This is normally matched to the radar
pulselength and is usually switched with
the range scale and the associated
pulselength. Narrow bandwidths of 3-5
MHz are used with long pulses on long
range and wide bandwidths of 10-25 MHz
with short pulses on short ranges.
Any radar bandwidth of less than 5 MHz
will attenuate the SART signal slightly, so it
is preferable to use a medium bandwidth to
ensure optimum detection of the SART.
Radar side lobes
As the SART is approached, sidelobes
from the radar antenna may show the
SART responses as a series of arcs or
concentric rings. These can be removed by
the use of the anti-clutter sea control
although it may be operationally useful to
observe the sidelobes as they may be
easier to detect in clutter conditions and
also they will confirm that the SART is near
to the ship.
GAIN
For maximum range SART detection the
normal gain setting for long range detection
should be used, that is, with background
noise speckle visible.
STC control
For optimum range SART detection, this
control should be set to the minimum. Care
should be exercised as a wanted target in
sea clutter may be obscured. Note also that
in clutter conditions the first few dots of the
SART response may not be detectable,
irrespective of the setting of the anti-clutter
sea control. In this case, the position of the
SART may be estimated by measuring 9.5
nm miles from the furthest dot back
towards own ship.
Some sets have automatic/manual anti-
clutter sea control facilities in which case
the operator should switch to manual.
FTC control
This should be used normally (to break up
areas of rain) when trying to detect a SART
response which, being a series of dots, is
not affected by the action of the anti-clutter
rain circuitry. Note that Racon responses,
which are often in the form of a long flash,
will be affected by the use of this control.
Some sets have automatic/manual anti-
clutter rain control facilities in which case
the operator should switch to manual.
When the range to the SART is reduced to
about 1 nm, the radar display may show
also the 12 responses generated during
the fast sweeps. These additional dot
responses, which also are equally spaced
by 0.64 nm, will be interspersed with the
original line of 12 dots. They will appear
slightly weaker and smaller than the
original dots.