Furuno FCR-2139S-BB - Page 72

2. RADAR, CHART RADAR OPERATION
2-6
How to read the graph
Using the X-band graph as an example, a radar target detected in rain on the 8 NM
range scale can only be detected at the ranges shown below:
4 mm/h rain (short pulse): approx 7.5 NM
16 mm/h rain (short pulse): approx 5.6 NM
4 mm/h rain (long pulse): approx 2.6 NM
16 mm/h rain (long pulse): approx 0.9 NM
Reduction of range of first detection (NM)
16 mm/h rain - short pulse
4 mm/h rain - short pulse
16 mm/h rain - long pulse
4 mm/h rain - long pulse
14
16
12
10
8
6
4
2
0
0 2 4 6 8 10 12 14 16
16
12
10
8
6
4
2
0
14
0 2 4 6 8 10 12 14 16
4 mm/h rain (short pulse)
16 mm/h rain (short pulse)
4 mm/h rain (short pulse)
16 mm/h rain (long pulse)
4 mm/h rain (short pulse)
16 mm/h rain (short pulse)
4 mm/h rain (long pulse)
16 mm/h rain (long pulse)
Original range of first detection (NM)
Original range of first detection (NM)
16 mm/h rain - short pulse
4 mm/h rain - short pulse
16 mm/h rain - long pulse
4 mm/h rain - long pulse
16 mm/h rain - short pulse
4 mm/h rain - short pulse
16 mm/h rain - long pulse
4 mm/h rain - long pulse
Reduction of rain to first detection due to rain at S-band
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.
Reduction of Range of First Detection (NM)Reduction of Range of First Detection (NM)