三副航海英语习题讲解3教学文稿.doc

三副航海英语习题讲解3

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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. distance 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 reading
B. A low-lying coastline with a long, flat 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 targets D. bearing of objects
D361. 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 radar
C. a sandy beach will show up clearer on radar than a rocky cliff
D. small wooden boats may not show up on radar
B327. 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 target 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 control
C. brilliance control D. 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 constant (differentiator)
D372. ______is on the panel of radar.
A.KEYLOCK B.REPEATER C.STATIC INVERTER D.ANTI-CLUTTER-SEA
A391. What is the purpose of VRM control?
A. To measure distance accurately B. To measure bearing accurately
C. 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．sweep introduction B．sweep interest C．sweep intention D．sweep 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 radar 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 conditions
C. radar bearing are less accurate than radar range
D. 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 ______ long．
A．a few centimeters B．a few fathoms C．a few meters D．a few feet
【知识点】雷达技术指标（波长）
【解析】航海雷达主要是3cm和10cm
C336. The 10-cm radar as compared to a 3-cm radar of similar specifications will ______.
A be more suitable for river and harbor navigation
B. provide better range performance on low lying targets during good weather and calm seas
C. have a wider horizontal beam 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 range performance in rain, hail, etc.
B. display small targets in a mass of dense sea clutter at a greater range
C. have less sea return in choppy rough seas
D. display a more maplike presentation for inshore navigation
A364. Coral atolls, or a chain of islands at right angles to the radar beam, may show as a long line rather than as individual targets due to ______.
A. the effects of beam width B. limitations on range resolution
C. 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 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 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 water
B. The contact is on the same course and speed as your vessel
C. The contact is on a reciprocal course at the same speed as your vessel
D. 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 vessel
C. on the same course and speed as your vessel
D. on a reciprocal course at the same speed as your vessel
D363. 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 contact?
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)t
C353. 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. 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 a(n)__
A. relative display B. composite display C. stabilized display D. unstabilized display
C392. 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 display. Which of the following will NOT appear to move across the PPI scope?
A. Echoes from a buoy
B. Own ship's marker
C. Echo from a ship on the same course at the same speed
D. 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 situation exists, the target causing the alarm condition are identified on {PPI} by a bright T adjacent thereto.
A. plan position indicator B. plane position indicator
C. 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 light 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 vessel’s position by radar ______.
A. should never use radar bearings
B. should only use radar bearings when the range exceeds the distance to the horizon
C. can use radar information from one object to fix the position
D. 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 ship’s position is ______.
A. keeping a close watch and lookout B. taking a radar range and bearing
C. observing a radar target and listening to signals D. keeping a well clear caution
C356. 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 changing 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 C.P.A. is the abbreviation of ______.
A. closest point to approach B. close point to approach
C. crossing point to approach D. fog or steady rain
【知识点】雷达标绘
【解析】CPA
C340. 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 radar
B. only if the radar scope is watched constantly
C. after the contact has been marked at least twice
D. 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 aspect
C. Producing large errors in calculated aspect D. Produce errors in calculated CPA / TCPA
B395. 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 seriously
B381. An indirect radar echo is caused by a reflection of the main lobe of the radar beam off the observer’s 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 appreciably
B. They always appear on a bearing of 90 degrees from the true bearing of the contact
C. The indirect echoes usually appear in shadow sectors
D. When plotted, their movements are usually abnormal
【知识点】假回波
【解析】间接反射假回波：雷达波经烟囱、大桅等间接反射到目标，目标回波经原路线回到天线形成。
特点：在阴影区内，一般方位不变。
A549. You have another ship overtaking you close aboard to starboard. You have 3 radar targets bearing 090° relative at ranges of 0.5 mile，1 mile，and 1.5 miles. In this case，the unwanted echoes are called ____.
A. multiple echoes B. spoking C. indirect echoes D. side-lobe echoes
【知识点】假回波
【解析】多次反射假回波：等间距，强度逐渐减弱。
A359. Which condition indicates that your radar needs maintenance?
A. Serrated range rings B. Indirect echoes C. Multiple echoes D. Blind sector
【知识点】雷达故障
【解析】固定距标圈呈现锯齿状时，雷达需要维修。
B543. Radar beacons are transmitters designed to produce a __ on the screens of ship’s radar sets.
A. incorrect image B. distinctive image C. pictorial image D. pictographic image
【知识点】雷达信标
【解析】雷达信标在雷达屏幕上产生独特的图像。
D 236. You are approaching a light fitted with a RACON. The light may be identified on the radar by___.
A. a dashed line running from the center of the scope to the light
B. an audible signal when the sweep crosses the light
C. a circle appearing on the scope surrounding the light
D. a coded signal appearing on the same bearing at a greater range than the light
【知识点】雷达信标
【解析】雷达信标在雷达上的图像。
相关题目
A362. You are scanning the radar screen for a buoy fitted with Racon. How should this signal appear on the PPI display？
A. starting with a dash and extending rapidly outward from the target
B. as a broken line from center of PPI to the target
C. starting with a dot and extending rapidly inward from the target
D. starting with a dash and extending to the right of the target
A332. It may be found that, in certain circumstances, Rader Beacon can cause unwanted interference particularly ______.
A. at close range B.at end on situation C. at head on situation D. at crossing situation
【知识点】雷达信标
【解析】近距离可能导致干扰杂波。
相关题目
A554. It may be found that, in certain circumstances, Rader Beacon emissions can cause ____ with the normal radar display, particularly at close range.
A. unwanted interference B. unexpected figures C. abnormal data D. unwanted information
D384. What does a Racon help with?
A. Measuring the distance B. Measuring the relative speed
C. Identifying a vessel D. Identifying a seamark
C387. What is a coded racon?
A. A racon which automatically activate itself
B. A racon only working at night
C. A racon which display a morse code on the radar screen
D. A future racon expected to be operational after Y2000
A385. How is an uncoded Racon displayed on the PPI?
A. As a line B. As a dot C. As small circle D. As a large circle
A386. What type of radar can activate a Racon?
A. X-band radar B. S-band radar C. C-band radar D. No radar can
D540. In order to insure that the racon signal is visible on your 3 cm radar, the ______.
A 10 cm radar should be placed on standby or turned off
B. gain control should be turned to maximum
C. radar should be stabilized, head up
D. rain clutter control should be off but, if necessary, may be on low
B344. The fitting of an efficient radar reflector is likely to considerably increase the ship’s probability of ____.
A. detection B. being detected C. the detective D. the detected
【知识点】雷达反射器
【解析】提高被探测到的可能性。
相关题目
D388. What is the purpose of the radar reflector?
A. Making objects less visible B. Making echoes weaker on the radar
C. Making large echoes smaller D. Making small objects better visible
B393. What is the correct speed input to an ARPA used for traffic surveillance?
A. Ground speed B. Speed through water C. Speed from GPS D. Speed from Doppler
【知识点】ARPA工作原理
【解析】交通监管用的ARPA应输入对水速度。
D338. The ARPA may swap targets when automatically tracking if two targets ______
A. are tracked on reciprocal bearings B. are tracked at the same range
C. are tracked on the same bearing D. pass close together
【知识点】ARPA自动跟踪存在的问题
【解析】自动跟踪时，如果两个目标相邻太近，ARPA可能会发生目标调换（误跟踪）。
两个或两个以上目标落入同一个波门而引起跟踪错误的现象
B350. What is TRUE of the history display of a target’s past positions on a ARPA?
A. It provides a graphic display to emphasize which vessel is on a collision course.
B. In the true presentation, it provides a quick visual check to determine if a vessel has changed course.
C. The display is one of the primary