11 航海仪器.doc

11 航海仪器11.2 雷达及ARPA的使用1211It may be found that，in certain circumstances，radar beacon emissions can cause _ with the normal radar display，particularly at close range A. unwanted interference B. unexpected figuresC. abnormal data D. unwanted information KEY: A1212My radar is not workingI require shore based radar assistanceIs shore based radar assistance _ ？ A. used B. available C. in use D. can be used KEY: B1213No assumptions _ on the basis of scanty information，especially scanty radar information A. should not be made B. are not to be taken C. should be taken D. shall be made KEY: D1214Proper use shall be made _ radar equipment A. with B. to C. for D. of KEY: D1215Radar 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 KEY: B1216Radar 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 KEY: A1217Radar reflectors are required for _. A. all fishing vessels over 39 feet in length B. sail-propelled fishing vessels C. all fishing vessels of less than 200 GT D. wooden hull fishing vessels with a poor radar echo KEY: D1218SWEEP INT on radar panel is the abbreviation of _. A. sweep introduction B. sweep interest C. sweep intention D. sweep intensity KEY: D1219The 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 KEY: C1220The 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 map like presentation for inshore navigation KEY: D1221The 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 KEY: D1222The articulated light is superior to other types of buoys because _. A. the radar reflectors reflect better signals B. fog horn signals travel farther to sea C. it is equipped with strobe lights D. it has a reduced watch circle KEY: D1223The 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 KEY: C1224The common way to obtain your ships 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 KEY: B1225The correct method of switching off a marine radar is to turn power switch to _ position first，then to _ position A. offstandby B. standbyoff C. standbyclose D. closestandby KEY: B1226The description Racon beside an illustration on a chart would mean a _. A. radar transponder beacon B. radar conspicuous beacon、 C. radar calibration beacon D. circular radiobeacon KEY: A1227The 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 KEY: B1228The officer of the watch should use radar when appropriate and at all times in _ waters A. congesting B. congested C. congestion D. congest KEY: B1229The 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) KEY: A1230The radar control that shortens all echoes on the display and reduces clutter caused by rain or snow is _. A. sensitivity time control (sea clutter control) B. receiver gain control C. brilliance control D. fast time constant (differentiator) KEY: D1231The radar control used to reduce sea return at close ranges is the _. A. gain control B. sensitivity time control C. fast time constant D. pulse length control KEY: B1232The 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 KEY: A1233The shoreline along Rocky Point should give a good radar return because _. A. the shore is bluff and rocky B. of offshore exposed rocks C. submerged reefs cause prominent breakers D. the lookout tower is marked with radar reflectors KEY: A1234To determine if risk of collision exists，a vessel which is fitted with radar must use _. A. radar scanning B. radar plotting C. compass bearings D. All of the above KEY: D1235Vessel required to have an Automatic Radar Plotting Aid must have a device to indicate the _. A. speed of the vessel over the ground or through the water B. distance to the next port C. time of the next navigational satellite pass D. None of the above KEY: A1236What is TRUE of the history display of a targets past positions on an 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 inputs and must be in use when using the trial maneuver capability. D. It provides a graphic display of a target vessels relative course，speed，and CPA. KEY: B1237What is TRUE when operating in fog and other vessels are detected by radar? _. A. You should make an ample change to port for a vessel crossing on the starboard bow. B. You should maneuver in ample time if a close-quarters situation is developing. C. You should determine the course and speed of all radar contacts at six minute intervals. D. Long-range scanning will provide early warning of ALL other vessels within the radars range. KEY: B1238What provides little or no indication that a vessel is dragging anchor? A. Increasing radar range to a fixed object ahead B. Drift lead with the line leading perpendicular to the centerline C. Vibrations felt by placing a hand on the cable D. Changing bearings to distant fixed objects abeam KEY: B1239What will cause the ARPA to emit a visual alarm，audible alarm，or both? A. An acquired target entering into a guard zone B. A tracked target lost for one radar scan C. A tracked target entering your preset CPA-TCPA limits D. A target being initially detected within a guard zone KEY: C1240When 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 KEY: D1241When navigating in thick fog with the radar on，you should _. A. station the look-out in the wheelhouse to keep a continuous watch on the radar B. secure the sounding of fog signals until a vessel closes within five miles C. station a look-out as low down and far forward as possible D. keep the radar on the shortest available range for early detection of approaching vessels KEY: C1242When 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 KEY: C1243When using an ARPA，what should you consider in order to evaluate the information displayed? A. The target vessels generated course and speed are based solely on radar inputs. B. Navigational constraints may require a target vessel to change course. C. The trial maneuver feature will automatically determine a course that will clear all targets. D. You cannot determine if a small target has been lost due to sea return. KEY: B1244When using the ARPA in heavy rain，which action should you take? A. Increase the radar gain to pick up weak echoes through the rain. B. Increase the STC setting to reduce close-in spurious signals. C. Navigate as though the effective range of the radar has been reduced. D. Increase the range of the inner and outer guard rings. KEY: C1245When 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 close 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 80to 85apart KEY: C1246When will the float-free emergency position indicating radiobeacon be activated after abandoning ship? A. Immediately after floating free B. After about one hour when the salt water activates the battery C. Only when keyed by the radar of another vessel D. Only when daylight activates the photovoltaic cell KEY: A1247When you turn on the fast time constant (differentiator) control of a radar it will _. A. enhance weak target echoes and brighten them on the PPI B. reduce clutter over the entire PPI by shortening the echoes C. only suppress weak targets to a limited distance from the ship (sea clutter) D. reduce the beam width to provide a map-like presentation for navigation KEY: B1248Which ARPA data should you use in order to determine if a close quarters situation will develop with a target vessel? A. Set and drift of the current B. Relative track information C. Predicted time of CPA D. Initial range of acquisition KEY: B1249Which condition indicates that your radar needs maintenance? A. Serrated range rings B. Indirect echoes C. Multiple echoes D. Blind sector KEY: A1250Which 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 bearings are less accurate than radar ranges. D. Radar should be checked regularly during clear weather to ensure that it is operating properly. KEY: B1251Which procedure(s) shall be used to determine risk of collision? A. Watching the compass bearing of an approaching vessel B. Systematic observation of objects detected by radar C. Long-range radar scanning D. All of the above KEY: D1252Which statement about an estimated position is TRUE? A. It is more reliable than a fix based on radar bearings. B. It may be based on a single LOP or questionable data. C. When a 3-LOP fix plots in a triangle，the center of the triangle is the estimated position. D. It is usually based on soundings. KEY: B1253Which statement concerning the operation of radar in fog is TRUE? 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. KEY: D1254Which statement is TRUE concerning a vessel equipped with operational radar? _. A. She must use this equipment to obtain early warning of risk of collision. B. The use of a radar excuses a vessel from the need of a look-out. C. The radar equipment is only required to be used in restricted visibility. D. The safe speed of such a vessel will likely be greater than that of vessels without radar. KEY: A1255Which statement is true concerning a vessel equipped with operational radar? _. A. The Master of the vessel must be on the bridge when the radar is in use. B. The radar equipment is only required to be used in restricted visibility. C. The use of a radar excuses a vessel from the need of a look-out. D. This equipment must be used to obtain early warning of risk of collision. KEY: D1256You 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 radially outward from the target B. As a broken line from center of PPI to the target C. Starting with a dot and extending radially inward from the target D. Starting with a dash and extending to the right of the target KEY: A1257You are underway at 5 knots and see on your radar a contact 10 miles directly astern of you. 12 minutes later，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 KEY: D1258You are underway in restricted visibility and hear a fog signal forward of the beam. Nothing appears on your radar screen. You must _. A. stop your engines B. sound two prolonged blasts of the whistle C. sound the danger signal D. slow to bare steerageway KEY: D1259You are underway in thick fog. You have not determined if risk of collision exists. Which statement is TRUE? _. A. Your speed must be reduced to bare steerageway. B. A look-out is not required if the radar is on. C. Fog signals are only required when a vessel is detected by radar. D. The radar should always be kept on a short-range scale. KEY: A1260You are using a radar in which your own ship is shown at the center，and the heading flash always points to 0. If bearings are measured in relation to the flash，what type of bearings are produced? A. Relative B. TRUE C. Compass D. Magnetic KEY: A11.3 磁罗经与陀螺罗经的使用1261If a magnetic compass is not affected by any magnetic field other than the Earths，which statement is TRUE? A. Compass error and variation are equal. B. Compass north will be true north. C. Variation will equal deviation. D. There will be no compass error. KEY: A1262If the compass heading and the magnetic heading are the same then _. A. the deviation has been offset by the variation B. there is something wrong with the compass C. the compass is being influenced by nearby metals D. there is no deviation on that heading KEY: D1263If the gyrocompass error is east，what describes the error and the correction to be made to gyrocompass headings to obtain true headings? A. The readings are too low (small numerically) and the amount of the error must be added to the compass to obtain true B. The readings are too low and the amount of the error must be subtracted from the compass to obtain true C. The readings are too high (large numerically) and the amount of the error must be added to the compass to obtain true D. The readings are too high and the amount of the error must be subtracted from the compass to obtain true KEY: A1264If the magnetic heading is greater than the compass heading，the deviation is _. A. east B. west C. north D. south KEY: A1265Indications of the master gyrocompass are sent to remote repeaters by the _. A. follow-up system B. transmitter C. phantom element D. azimuth motor KEY: B1266Knowing the compass heading that is 90to the side of a ship will enable the operator of a survival craft to initially steer _. A. into the wind B. away in fire and smoke C. directly to the standby boat D. directly to the nearest land KEY: B1267Magnetic compass deviation _. A. varies depending upon the bearing used B. is the angular difference between magnetic north and compass north C. is published on the compass rose on most nautical charts D. is the angular difference between geographic and magnetic meridians KEY: B1268Magnetic dip is a measurement of the angle between the _. A. geographic pole and the magnetic pole B. lubbers line and true north C. horizontal and the magnetic line of force D. compass heading and the magnetic heading KEY: C1269Magnetic heading differs from compass heading by _. A. compass error B. true heading C. variation D. deviation KEY: D1270Magnetic variation changes with a change in _. A. the vessels heading B. sea conditions C. seasons D. the vessels position KEY: D1271Magnets are placed in horizontal trays in the compass binnacle to compensate for the _. A. induced magnetism in the vessels horizontal soft iron B. change in the magnetic field when the vessel inclines from vertical C. permanent magnetism of the vessel D. magnetic fields caused by electrical currents in the vicinity KEY: C1272Quadrantal error in a gyrocompass has its GREATEST effect _. A. in high latitudes B. near the equator C. on north or south headings D. on intercardinal headings KEY: D1273The compass deviation changes as the vessel changes _. A. geographical position B. speed C. heading D. longitude KEY: C1274The compass error of a magnetic compass that has no deviation is _. A. zero B. equal to v