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精品资料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 readingB. 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 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 radarB327. 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 controlC. 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-SEAA391. 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_Asweep 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 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 conditionsC. 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 meters 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 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 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 as 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 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 waterB. The contact is on the same course and speed as your vesselC. The contact is on a reciprocal 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 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 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)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. 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 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 display. 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 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 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 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 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 radar 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 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 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 approachC. crossing 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 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 aspect 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 of 90 degrees from the true bearing of the contactC. The indirect echoes usually appear in shadow sectorsD. 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 ships 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 lightB. an audible signal when the sweep crosses the lightC. a circle appearing on the scope surrounding the lightD. 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 targetB. as a broken line from center of PPI to the targetC. starting with a dot and extending rapidly inward from the target D. starting with a dash and extending to the right of the targetA332. 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 informationD384. What does a Racon help with?A. Measuring the distance B. Measuring the relative speedC. 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 nightC. A racon which display a morse code on the radar screen D. A future racon expected to be operational after Y2000A385. 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 circleA386. 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 offB. gain control should be turned to maximum C. radar should be stabilized, head upD. rain clutter control should be off but, if necessary, may be on lowB344. The fitting of an efficient radar reflector is likely to considerably increase the ships 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 visibleB393. 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 rangeC. 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 targets 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