Furuno FAR-2218 Operator's Manual page 55

How to interpret the graph
Using the graph below as an example, a radar target originally detected on the 8 NM
range can only be detected in rain at the ranges shown below:
16
16 mm/h rain - short pulse
14 4 mm/h rain - short pulse
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.
Accordingly, the short pulse may be preferable in rain on ranges less than 10 NM.
4 6 8
Original range of first detection (NM)
4 6 8
Original range of first detection (NM)
1. OPERATIONAL OVERVIEW
10 12 14
10 12 14
4 mm/h rain (short pulse)
16 mm/h rain (short pulse)
4 mm/h rain (long 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
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