Chapter 3
TRUE AND FALSE ECHOES ON DISPLAY
3.1
RADAR WAVE WITH THE HORIZON
3-1
3
INS
TRUCT
IO
N
M
ANUAL
Chapter 3
TRUE AND FALSE ECHOES ON
DISPLAY
The radar operator has a role of interpreting the radar displays to provide his best aid in
maneuvering the ship.
For this purpose, the operator has to observe the radar displays after fully understanding
the advantages and disadvantages that the radar has.
For better interpretation of radar display, it is important to gain more experiences by
operating the radar equipment in fair weathers and comparing the target ships watched
with the naked eyes and their echoes on the radar display.
The radar is mainly used to monitor the courses of own ship and other ships in open seas,
to check buoys and other nautical marks when entering a port, to measure own ship’s
position in the coastal waters relative to the bearings and ranges of the shore or islands
using a chart, and to monitor the position and movement of a heavy rain if it appears on
the radar display. Various types of radar display will be explained below.
3.1
RADAR WAVE WITH THE HORIZON
Radar beam radiation has the nature of propagating nearly along the curved surface of
the earth. The propagation varies with the property of the air layer through which the
radar beam propagates. In the normal propagation, the distance (D) of the radar wave to
the horizon is approximately 10% longer than the distance to the optical horizon. The
distance (D) is given by the following formula:
' ¥K
+
¥KQP
h1: Height (m) of radar scanner above sea level
h2: Height (m) of a target above sea level
Fig. 3.1-1 is a diagram for determining the maximum detection range of a target that is
limited by the curve of the earth surface in the normal propagation.
Fig. 3.1-1
D
㻱㼍㼞㼠㼔
h
1
h
2
Radar
Targets
Summary of Contents for JMA-3300 Series
Page 2: ......
Page 16: ...WARNING LABEL MOUNTING POINT xiv NCD 2182 Display Unit ...
Page 17: ...WARNING LABEL MOUNTING POINT xv NBA 5111 Power Supply NBD 865 Rectifier unit ...
Page 30: ...GLOSSARY xxviii ...
Page 46: ...Chapter 1 GENERAL AND EQUIPMENT COMPOSITION 1 5 GENERAL SYSTEM DIAGRAMS 1 16 ...
Page 244: ...Chapter 4 MAINTENANCE 4 6 TROUBLE SHOOTING 4 36 ...
Page 266: ...APPENDIX APPENDIX 2 Fig A2 NKE 2043 SCANNER INTERCONNECTION DIAGRAM ...
Page 268: ...APPENDIX APPENDIX 4 Fig A4 NKE 2062HS SCANNER INTERCONNECTION DIAGRAM ...
Page 271: ...APPENDIX APPENDIX 7 APPENDIX INSTRUCTION MANUAL LJ 1 6 6 11 5 17 5 211 7 21 5 0 ...
Page 272: ...APPENDIX APPENDIX 8 Fig A8 NKE 2063AHS SCANNER INTERCONNECTION DIAGRAM ...
Page 274: ...APPENDIX APPENDIX Fig A NCD 2182 DISPLAY UNIT INTERCONNECTION DIAGRAM ...
Page 276: ...APPENDIX APPENDIX 1 Fig A1 JMA 3314 INTERCONNECTION DIAGRAM ...
Page 277: ...APPENDIX APPENDIX 1 APPENDIX INSTRUCTION MANUAL Fig A1 JMA 3334 INTERCONNECTION DIAGRAM ...
Page 278: ...APPENDIX APPENDIX 1 Fig A1 JMA 3316 HS INTERCONNECTION DIAGRAM ...
Page 280: ...APPENDIX APPENDIX 1 Fig A1 JMA 3340 4 4HS 6 6HS INTERCONNECTION DIAGRAM ...
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