Radar Observation and Plotting Q&A

CD-0049

Radar Observation and plotting

1

What is the fundamental principle of a marine radar? Detection of other objects outside own ship.

2

How is the amplifier protected from fro m the transmitted pulse? By the Transmitter/Receiver switch.

3

What is the relation between the scanners hori!ontal width "si!e# and hori!ontal beam width? $ar%e scanner hori!ontal width& narrow hori!ontal beam width.

4

What is the main function of the antenna? To transmit transmit the radar si%nals and receive echoes from objects. obje cts.

5

How does radar antenna hei%ht influence on sea clutter? Hi%h antenna hei%ht results in more sea clutter displayed on the screen.

6

What is the main function of the receiver? 'mplify the incomin% si%nals.

7

What is the correct settin% for the ()ain* control? ' little noise "spec+led effect# remainin% visible on the screen.

8

How can the hori!ontal e,tent of a (Blind -ector* be accurately determined? By turnin% the ship throu%h 0 de%rees and determinin% when a stron% echo disappears and reappears on the radar screen.

9

Does the ships trim affect radar minimum ran%e? 1es& it may introduce obstructions and blind sectors. 2nly at short distance.

10

3an the fre4uency of radar pulses transmitted per second affect the radars ma,imum ran%e? 1es.

11

What is the meanin% of (radars Ran%e Discrimination*? The radar ability to display as separate spots on the screen& close tar%ets on the same bearin%.

12

What is the meanin% of (radar Bearin% Discrimination*? The radar ability to display as separate spots on the screen& close tar%ets on the same ran%e.

13

The reflection of radar pulses is similar to that of? $i%ht waves.

14

What is +nown as (-ide $obes* with reference to marine radar? 5nwanted lobes of ener%y transmitted outside the main radar transmission beam.

15

We have normal transmission of radar waves when the radar hori!on is? 607 lon%er than the visible hori!on.

16

Which radar condition can be associated with a temperature inversion? Ductin%.

17

What is the effect of -ub8refraction? Distance to the radar hori!on is reduced.

18

What is the purpose of the )ain control? To adjust adjust the amount of amplification of the echoes.

CD-0049

Radar Observation and plotting

19

What is the purpose of the 'nti -ea 3lutter controls? Reduces the affects of the echo returns from the sea waves.

20

9arine radar bearin% accuracy is %enerally? )ood& but not as %ood as the ran%e rin%s.

21

9arine radar ran%e accuracy is %enerally? )ood& but the ran%e rin%s are better than the :R9.

22

Which course should be fed in to the radar with a stabilised radar picture? True course steered by own ship.

23

How can the Beam Width Distortion be minimi!ed? Reduce the settin% of the )ain control.

24

What is the purpose of the Headin% $ine "H$# 8suppression control To switch off the H$ temporarily in order to see under the line on the screen.

25

What is the purpose of the :R9 control? To measure distance of a tar%et on the screen accurately from own ship.

26

;92 resolution <== applies to all ships built after? 6><

27

What is the minimum radar display diameter for ships of 60 000 tons and upwards? 6 inch

28

What is the re4uired accuracy of the headin% mar+er? @/8 6.0A

29

;s it a re4uirement to have the H98suppress button sprin% loaded? 1es& it is a ;92 re4uirement.

30

What is the ma,imum radar (warm8up* time? < min

31

What is the minimum number of ran%e scales re4uired? 

32

What is the minimum display diameter re4uired on ships bi%%er than 600 tons but less than 60 000 tons? C0 mm

33

The radar must be able to operate in relative wind speeds up to? 600 +nots

34

What is the main purpose of plottin%? 2btain information about whether dan%er of collision e,ists& 3'& T3'& tar%et course and speed.

35

Which of the followin% provides the complete answer& when related to the effect of usin% incorrect bearin%s in plottin%? 3'& T3'& 3ourse and -peed of the tar%et are effected.

36

What is the effect of %yro error? 'll bearin%s will be wron%.

CD-0049

Radar Observation and plotting

37

What is the effect of error in own ships speed& when completin% a plot? Error in the tar%ets course and speed.

38

What is the purpose of determinin% the 'spect of a tar%et vessel ? rovide the same information as could be seen visually out of the wheelhouse window.

39

What is the 4uic+est method of decidin% whether collision dan%er e,ists or not? By ta+in% several bearin%s of the tar%et.

40

What is the main disadvanta%e of true plottin%? 3ollision ris+ "3'# can only be found by completin% the plot.

41

When completin% a full Relative plot "Forth up#& what input information is re4uired? ' series of tar%et ran%es and bearin%s and own ships course and speed throu%h the water.

42

Why should radar still be used durin% the day in clear visibility? To improve confidence and competence in the use of that specific radar.

43

What is the purpose of a radar reflector? 9a+in% small objects more radar visible.

44

When does a radar display the identity si%nal of a racon? When the wavelen%th of the racon is similar to the radar in use.

45

What is sometimes +nown as a 3oded Racon? ' racon which displays a 9orse code on the radar screen.

46

What is the main purpose of the parallel inde, lines? To assist the navi%ator in maintainin% the desired course over the %round..

47

Which of the radar controls can be left at the settin% determined when the set was first switched on? Fone.

48

What is the correct type of radar display to be selected when at sea? 'lways use a compass stabili!ed display either True 9otion or Relative 9otion to suit e,perience and environment.

49

What radar ran%e should be selected to suit all conditions? The ran%e most suitable to the pro,imity of tar%ets and land& but with fre4uent chec+s of hi%her and lower ran%es.

50

Does the 3ollision Re%ulations %ive any preference to ships e4uipped with radar? Fo.

51

What is the main content of Rule 6> in the 3ollision Re%ulations? The conduct of vessels in restricted visibility.

52

The action ta+en to avoid collision in reduced visibility should beG ositive& in ample time and avoidin% a series of small alterations.

53

The actions re4uired by the 3ollision Re%ulations can be i%nored whenG Fever.