How To Reduce Rain Clutter Manually - Furuno FCR-21x9-BB Operator's Manual

2. RADAR, CHART RADAR OPERATION
2.8.2

How to reduce rain clutter manually

Control Unit: Push the RAIN control to display [MAN] on the [RAIN] mode indication
on the Status bar. While watching the radar picture, adjust the RAIN control to reduce
the clutter.
Trackball module: Click the [RAIN] mode indication on the Status bar to show [MAN].
For coarse adjustment, put the cursor within the slider bar area then push the left but-
ton. For fine adjustment, put the cursor at the end of the slider bar then roll the trackball
while pushing and holding down the left button. Release the button to finish.
Note: The detection range is reduced when the RAIN is used to show targets in rain.
Generally, the amount of rain, TX pulse length and TX frequency are factors in deter-
mining how the detection range is affected. The figures shown below illustrate this oc-
currence.
16
16 mm/h rain - short pulse
4 mm/h rain - short pulse
14
16 mm/h rain - long pulse
4 mm/h rain - long pulse
12
10
16 mm/h rain - short pulse
8
4 mm/h rain - short pulse
16 mm/h rain - long pulse
4 mm/h rain - long pulse
6
4
2
0
0 2
Reduction of rain to first detection due to rain at S-band
16
16 mm/h rain - short pulse
4 mm/h rain - short pulse
14
16 mm/h rain - long pulse
4 mm/h rain - long pulse
12
10
8
6
4
2
0
0 2
Reduction of rain to first detection due to rain at X-band
The author thanks the International Electrotechnical Commission (IEC) for permission to reproduce
Information from its Interantional Standard IEC 62388 ed.1.0 (2007). All such extracts are copyright of
IEC, Geneva, Switzerland. All rights reserved. Further information on the IEC is available from
www.iec.ch. IEC has no responsibility for the placement and context in which the extracts and
contents are reproduced by the author, or is IC in any way responsible for the other content or
accuracy therein.
2-10
4 6 8
Original range of first detection (NM)
4 6 8
Original range of first detection (NM)
10 12 14
10 12 14
4 mm/h rain (short pulse)
16 mm/h rain (short pulse)
4 mm/h rain (short pulse)
16 mm/h rain (long pulse)
16
4 mm/h rain (short pulse)
4 mm/h rain (long pulse)
16 mm/h rain (short pulse)
16 mm/h rain (long pulse)
16