How To Show Sart Marks On The Radar Display; General Remarks On Receiving Sart - Furuno FCR-2107 Operator's Manual

3.3.2

How to show SART marks on the radar display

This radar is equipped with a feature that optimally sets up the radar for SART detection. This feature automatically
detunes the radar receiver out of its best tuning condition. This erases or weakens all normal radar echoes, but the
SART marks are not erased because the SART response signal scans over all frequencies in the 9 GHz band. When
the radar approaches the SART in operation, the SART marks will enlarge to large arcs, blurring a large part of the
screen.
To set up for SART detection do the following:
1. Use the trackball to select the MENU box then push the left button.
2. Spin the scrollwheel to select Echo then push the left button.
[Echo]
Go Back
2nd Echo Rej
PM
SART
Tune Initialize
Echo menu
3. Spin the scrollwheel to select SART then push the scrollwheel. Check to set up for SART, uncheck for normal
operation.
4. With SART turned on, radar functions are automatically set as follows:
Range: 12 nm
Pulse Length: Long
Echo Stretch: Off
Noise Rejector: Off
Echo Averaging: Off
Interference Rejector: Off
Performance Monitor: Off
A/C Rain:Off
"SART" appears when this feature is active. Be sure to turn off the SART feature when SART detection is no longer
your objective.
3.3.3

General remarks on receiving SART

SART range errors
When responses from only the 12 low frequency sweeps are visible (when the SART is at a range greater than about
1 nm), the position at which the first dot is displayed may be as much as 0.64 nm beyond the true position of the
SART. When the range closes so that the fast sweep responses are seen also, the first of these will be no more than
150 meters beyond the true position.
Radar bandwidth
This is normally matched to the radar pulse length and is usually switched with the range scale and the associated
pulse length. Narrow bandwidths of 3-5 MHz are used with long pulses on long range scales and wide bandwidths
of 10-25 MHz with short pulses on short ranges.
A 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, side lobes 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 side lobes as they may be easier to detect in clutter conditions and also they will confirm that
the SART is near to own ship.
Note: SART information excerpted from IMO SN/Circ 197 OPERATION OF MARINE RADAR FOR SART
DETECTION.
3. Radar Observation
3-5