三副航海英语习题讲解.docx

1、三副航海英语习题讲解2017航海英语复习三Key word 10: Radar and ARPA（60）A335. Radar makes it possible and much safer for us to sail _.A. in dense fog B. in boisterous weather C. in the open sea D. in rivers【知识点】雷达的使用【解析】主要作用：雾航B380. Radar makes the most accurate determination of the _.A. direction of a target B. distan

2、ce to a target C. size of a target D. shape of a target【知识点】雷达的使用【解析】雷达测距最准确。相关题目A382. Without doubt the radar is a highly important navigation aid. But duty officer shall aware that _when using it.A. Its range reading is more accurate than its bearing readingB. A low-lying coastline with a long, fl

3、at beach will show up properly on the radar.C. Radar is only aimed at collision avoidance.D. the use of radar is necessary only when visibility is restricted、D527. Radar is not only to obtain _, but also to measure their distance away from you.A. brightness of objects B. color of targets C. shape of

4、 targets D. bearing of objectsD361. Which statement concerning the operation of radar in fog is TURE ?A. radar ranges are less accurate in fog B. navigation buoys will always show up on radarC. a sandy beach will show up clearer on radar than a rocky cliffD. small wooden boats may not show up on rad

5、arB327. The correct method of switching off a marine radar is to turn power switch to _ position first, then to _ position.A. off / standby B. standby / off C. standby / close D. close / standby【知识点】雷达的使用【解析】雷达关机步骤。B606、As the radar antenna scans through _ a rotation , it can be show where the targe

6、t is relative to your position .A. 60 degree B. 360 degree C. 180 degree D. 90 degree【知识点】雷达的使用【解析】雷达天线。A345. The radar control that reduces weak echoes out to a limited distance from the ship is the _A. sensitivity time control ( sea-clutter control) B. receiver gain controlC. brilliance control D.

7、 fast time constant ( differentiator )【知识点】雷达的使用（控钮）【解析】近距离的杂波相关题目D346. The radar control that shortens all echoes on the display and reduces clutter caused by rain or snow is the _. A. sensitivity time control (sea clutter control) B. receiver gain control C. brilliance control D. fast time constan

8、t (differentiator)D372. _is on the panel of radar. INVERTER A391. What is the purpose of VRM control?A. To measure distance accurately B. To measure bearing accuratelyC. To measure range and bearing D. To adjust radar monitor【知识点】雷达的使用【解析】活动距标圈。D557. SWEEP INT on radar panel is the abbreviation of_A

9、sweep introduction Bsweep interest Csweep intention Dsweep intensity【知识点】雷达的使用【解析】扫描亮度A605、When will you have to adjust gain ?A. every time you change ranges B. each watch C. every day D. every week【知识点】雷达的使用【解析】增益：每次改变量程后需重新调整。D352. When hitting a solid object such as a ship or an airplane, the rad

10、ar waves are reflected back _ they came.A. in the way B. the way C. by the way D. through the path【知识点】雷达的工作原理【解析】雷达波路径B360. Which general statement concerning radar is FALSE?A. raising the antenna height increases the radar range B. the ability of radar to detect objects is unaffected by weather co

11、nditionsC. radar bearing are less accurate than radar rangeD. radar should be checked regularly during clear weather to ensure that it is operating properly 【知识点】雷达的工作原理【解析】雷达探测物标的能力会受到天气的影响。A348. The radio waves used for radar are very short，only _ longAa few centimeters Ba few fathoms Ca few meter

12、s Da few feet【知识点】雷达技术指标（波长）【解析】航海雷达主要是3cm和10cmC336. The 10-cm radar as compared to a 3-cm radar of similar specifications will _.A. be more suitable for river and harbor navigationB. provide better range performance on low lying targets during good weather and calm seasC. have a wider horizontal be

13、am width D. have more sea return during rough sea conditions【知识点】雷达技术指标（波长）【解析】1）最大作用距离：正常天气下，3cm雷达的大；雨雪天，10cm雷达的大。 2）距离分辨力和测距精度：波长短，脉冲前沿短，脉冲宽度短3cm好。3）方位分辨力和测方位精度：波长越短，波束宽度越窄3cm好。4）抗杂波能力：10cm好。相关题目D337. The 3-cm radar as compared to a 10-cm radar with similar specifications will _.A. give better ran

14、ge performance in rain, hail, etc.B. display small targets in a mass of dense sea clutter at a greater rangeC. have less sea return in choppy rough seasD. display a more maplike presentation for inshore navigationA364. Coral atolls, or a chain of islands at right angles to the radar beam, may show a

15、s a long line rather than as individual targets due to _.A. the effects of beam width B. limitations on range resolutionC. the pulse length of the radar D. the multiple-target resolution factor【知识点】雷达技术指标（天线波束宽度）【解析】天线水平波束宽度对方位分辨力的影响。A 237. You are using radar in which your own ship is shown at the

16、center, and the heading flash always points to 00. If bearings are measured in relation to the flash, _ bearing are produced. A. relative B. true C. compass D. a circle appearing on the scope surrounding the light【知识点】雷达显示方式【解析】首向上显示方式B331. You have been observing your radar screen and notice that a

17、 contact on the screen has remained in the same position, relative to you, for several minutes. Your vessel is making 10 knots through the water. Which statement is TRUE?A. The contact is dead in the waterB. The contact is on the same course and speed as your vesselC. The contact is on a reciprocal

18、course at the same speed as your vesselD. The radar is showing false echoes and is probably defective【知识点】雷达显示方式【解析】相对运动相关题目C374. A radar contact will remain stationary on a relative motion radar display only when it is _.A. on the same course as your vessel B. at the same speed as your vesselC. on

19、the same course and speed as your vesselD. on a reciprocal course at the same speed as your vesselD363. You are underway at 5 knots and see on your radar a contact 10 miles directly astern of you. 12 minutes latter, the contact is 8 miles directly astern of you. What is the estimated speed of the co

20、ntact? A. dead in the water B. 1 knot C. 10 knots D. 15 knots【知识点】雷达显示方式【解析】相对运动：d=(V2-V1)tC353. When using a radar in a unstabilized mode, fixes are determined most easily from _.A. center bearings B. tangent bearings C. ranges D. objects that are close aboard【知识点】雷达显示方式【解析】不稳定显示方式首向上，航向变，方位变。B375.

21、 A radar display in which North is always at the top of the screen is a(n) _.A. unstabilized display B. stabilized display C. composition display D. relative display【知识点】雷达显示方式【解析】北向上稳定显示方式。相关题目C376. A radar display which is oriented,（标定方向） so that north is always at the top of the screen, is called

22、 a(n)_A. relative display B. composite display C. stabilized display D. unstabilized displayC392. What course should be fed into a stabilized radar picture?A. Compass course B. Gyro course C. True course D. Course made good【知识点】雷达显示方式【解析】稳定显示方式：使用航向为真航向。A529. Your radar is set on a true motion displ

23、ay. Which of the following will NOT appear to move across the PPI scope?A. Echoes from a buoy B. Own ships markerC. Echo from a ship on the same course at the same speedD. Echo from a ship on a reciprocal course at the same speed【知识点】真运动【解析】真运动模式A339. When the system determines that a collision situ

24、ation exists, the target causing the alarm condition are identified on PPI by a bright T adjacent thereto.A. plan position indicator B. plane position indicatorC. policy proof of interest D. policy proof of interest【知识点】雷达显示【解析】平面位置显示器相关题目B377. A radar range to a small, charted object such as a ligh

25、t will provide a line of position in which form? A. Straight line B. Arc C. Parabola D. Hyperbola【知识点】雷达测距【解析】距离位置线C330. A navigator fixing a vessels position by radar _.A. should never use radar bearingsB. should only use radar bearings when the range exceeds the distance to the horizonC. can use r

26、adar information from one object to fix the positionD. must use information from targets forward of beam【知识点】雷达定位【解析】雷达定位方法。相关题目B342. The common way to obtain your ships position is _.A. keeping a close watch and lookout B. taking a radar range and bearingC. observing a radar target and listening to

27、 signals D. keeping a well clear cautionC356. When using the radar for navigating_.A. The best fix is obtained by using a tangent bearing and a range.B. And using two radar ranges for a fix, the objects of the ranges should be closed to reciprocal bearings.C. And using ranges, the most rapidly chang

28、ing range should be measured last.D. And crossing a radar range of one object with the visual bearing of a second object, the two objects should be 80 to 110 apart.【知识点】雷达定位【解析】测距定位时，距离变化快的后测。A341. In radar plotting is the abbreviation of _.A. closest point to approach B. close point to approachC. c

29、rossing point to approach D. fog or steady rain【知识点】雷达标绘【解析】CPAC340. The closest point of approach ( CPA ) of a contact on a relative motion radar may be determined _.A. immediately when the contact is noted on radarB. only if the radar scope is watched constantlyC. after the contact has been marked

30、 at least twiceD. by an occasional glance at the radar【知识点】雷达标绘【解析】CPA的标绘方法：固定的时间间隔确定两个以上位置，连线即得相对运动线。相关题目A394. How does current and drift effect the relative motion, relative vector presentation?A. No effect B. Producing small errors in calculated aspectC. Producing large errors in calculated aspec

31、t D. Produce errors in calculated CPA / TCPAB395. Does current and drift effect the CPA / TCPA calculations on a true motion display?A. Yes B. No C. Only a little bit D. Yes, very seriouslyB381. An indirect radar echo is caused by a reflection of the main lobe of the radar beam off the observers vessel. Which of the following is not a characteristic of indirect echoes?A. Their bearing is almost constant, even when the true bearing of the contact changes appreciablyB. They always appear on a bearing o