Simrad ARGUS FMCW 3G, User Manual

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Radar presentation and video processing | Argus Radar Operator Manual
Furthermore:
When only the responses generated by the slow sweeps are visible (when the SART is at a
range greater than approx. 1 NM), the position of the SART must be estimated 0.64 NM closer
than first dot. Whereas, when the distance from the SART is short and the responses gener-
ated by the fast sweep are visible, the position of the first of these will be no more than 150 m
beyond the true position of the SART. The long pulse should attenuate the SART response, for
this reason, if using a range scale of 24 NM, it is recommended to proceed as follows:
•
Select the “Short Range Small Echoes” preset video processing.
•
Set the Gain control at 80%.
•
Set Sea Control at minimum.
This way the “Power Pull Down” function will be activated and the transceiver will use the
medium pulse for the 24 NM range scale and the short pulse for the 6 and 12 NM range scale.
Getting closer to the SART and changing the range scale to under 6 NM it is recommended to
return to the “Standard Video Proc”.
As the SART is very near, side lobes from the radar antenna may show the SART responses as a
series concentric arcs or rings. This effect can be removed by using the sea control.
Anyway, it could be operationally useful to observe the side lobes as they might be easier to
detect in clutter conditions and also they will confirm that the SART is very near to own ship.
To improve the visibility of the SART in clutter conditions, the radar may be detuned to reduce
the clutter response without reducing the SART signal. To perform this operation, the tuning
must be set to manual and the potentiometer moved to one side. The operator should take
care when doing this, because the detuned Radar will not be able to see and track targets as
it will when it is tuned. And the anti-collision functions may no longer be working. The tuning
should be returned to normal as soon as possible.
¼
Note:
SART can be revealed on X Band radar only. Small echoes are displayed on short pulse
only.
Screen A: SART is far away. Screen B: SART is close.
The lines are shown as concentric arcs.
SART signal on the monitor