Section 7 True and False Echoes on Display
7-4
7.3 Sea Clutter and Rain/Snow Clutter
In addition to the echoes required for observing ships and land, radar video images that are displayed
also include undesirable echo images, such as reflection from waves on the sea surface and reflection
from rain and snow. Reflection from the sea surface is called sea clutter and reflection from rain, snow,
and cloud is called rain and snow clutter. Those interfering waves must be eliminated by the clutter
rejection function ([Settings] – [Signal Process] – [Video Noise Rejection]). (Refer to “13.2 Setting
Radar Signal Processing”.)
7.3.1 Sea clutter
Sea clutter appears as an image radiating outwardly from the centre of the radar display and changing
depending on the size and the shape of waves. Generally, as waves become larger, image level of the
sea clutter is intensified and the clutter far away is also displayed. In this case, it is difficult to
distinguish sea clutter from a small boat whose reflection intensity is weak. Accordingly, it is necessary
to properly adjust the sea clutter rejection function.
The following tables show the relation between the sea state (SS) showing the size of waves
generated by wind and the radar's detection probability.
Sea State and Probability of Target Detection
RCS
SS1 to 2 SS2 to 3 SS3 to 4 SS4 to 5
0.1 m
2
V
V-M
M-NV
0.5 m
2
V
V
V-M
M-NV
1 m
2
V
V
V
V-M
S band radar (probability to detect a target at a range of 0.4 NM)
RCS
SS1 to 2 SS2 to 3 SS3 to 4 SS4 to 5
1m
2
V-M
M-NV
5 m
2
V
V-M
M-NV
10 m
2
V
V
V
V-M
X band radar (probability to detect a target at a range of 0.7 NM)
V: Detection probability of 80 %
M: Detection probability of 50 %
NV: Detection probability of less than 50 %
Содержание JMR-5410-4X
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Страница 54: ...Contents 20 ...
Страница 68: ...Section 1 Overview 1 14 Outline Drawing of Radar Antenna NKE 2632 A ...
Страница 70: ...Section 1 Overview 1 16 Outline Drawing of Radar Antenna NKE 2043 NKE 2043 ...
Страница 72: ...Section 1 Overview 1 18 Outline Drawing of Radar Antenna NKE 2103 4 4HS ...
Страница 74: ...Section 1 Overview 1 20 Outline Drawing of Radar Antenna NKE 2255 7 ...
Страница 76: ...Section 1 Overview 1 22 Outline Drawing of Radar Antenna NKE 2255 6HS ...
Страница 78: ...Section 1 Overview 1 24 Outline drawing of 19inch Display NWZ 214 NWZ 214 ...
Страница 80: ...Section 1 Overview 1 26 Outline Drawing of Process Unit NDC 1678 NDC 1678 ...
Страница 82: ...Section 1 Overview 1 28 Outline Drawing of Trackball Operation Unit NCE 5605 Option ...
Страница 84: ...Section 1 Overview 1 30 Outline Drawing of Junction Box NQE 1143 ...
Страница 86: ...Section 1 Overview 1 32 Outline Drawing of 19inch Desktop Frame CWB 1659 ...
Страница 88: ...Section 1 Overview 1 34 Outline Drawing of Interswitch Unit NQE 3141 8A Option ...
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Страница 214: ...Section 4 Range and Bearing Measurement Methods 4 32 ...
Страница 244: ...Section 5 Basic Operation of the Radar 5 30 ...
Страница 324: ...Section 8 Monitoring a Dragging Anchor 8 8 ...
Страница 374: ...Section 11 Setting up Screen View 11 20 ...
Страница 380: ...Section 12 Setting up Alerts 12 6 Polygon tab Set a polygon alarm issuing range This function cannot be used now ...
Страница 520: ...Section 15 Maintenance Inspection 15 70 ...
Страница 546: ...Section 16 Failures and After Sale Services 16 26 ...
Страница 590: ...Appendix A Radar Antenna Display Unit Block Diagrams A 8 A 1 8 NKE 2255 7 9 6HS ...
Страница 592: ...Appendix A Radar Antenna Display Unit Block Diagrams A 10 A 1 10 NKE 2063A ...
Страница 596: ...Appendix A Radar Antenna Display Unit Block Diagrams A 14 A 2 3 NCE 5794 operation unit ...
Страница 622: ...Appendix D Menu List and Materials D 8 Tools VHF Call VHF1 Call VHF2 Call VHF3 Call ...
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