C3 - Use of Radar and ARPA for the safety of navigation (200)

100問 • 2年前

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101. How long will it takes for the radar to be fully operational from the STANDBY position?

•Within 5 seconds

102. How much time frame should an ARPA present a steady state in tracking the motion of a target with a 95% probabilty accuracy value?

•Within 3 minutes

103. What is the required frequency of radar to be fitted on a 10, 000 gross tonnage ship as per Solas V regulation 19?

•9 GHz frequency band

104. You radar has a beam width of 2. The gyro bearing of the right tangent of an island is 316. The gyro error is 1E. Which true bearing should be plotted on the chart?

•316

105. What is TRUE of the history display of a target's past position on an ARPA?

•In the true presentation, it provides a quick visual check to determimne if a vessel has changed coutrse

106. What is the name given to unwanted radial lines that sometimes appear on the radar screen?

•Spoking

107. What should you do to establish an additional radar target data other than Closest Point of Approach on a relative plot?

•Draw a relative velocity triangle

108. What is the most accurate determination that a radar can make?

•Distance to a target

109. What statement is TRUE when operating in fog and other vessels are detected by radar?

•You should maneuver in accordance with the steering and sailing rules

110. Which of the following is the approximate time a radar pulse travel out to and the echo return from a target at 24 miles?

•400 microsec

111. What is the modulation frequency of most RADAR systems?

•Between 60 and 500 Hz

112. Identify the correct manual plot vector label that best represents an ARPA relative vector information?

•r-m

113. What is the ability of a radar set to clearly distinguish two targets, on the same range and slightly different bearings, as two separate targets on the PPI?

•Bearing discrimination

114. What is the name of the movable guide line used to measure direction on a radar?

•Cursor

115. In what time frame an ARPA should present a steady state tracking the motion of a target with the following accuracy (95% accuracy values)?

•Within 3 minutes

116. What is the intermediate frequency of a shipboard radar unit?

•30 to 60 MHz

117. Your ARPA has automatic speed inputs from the log. Due to currents, the log is indicating a faster speed than the speed over the ground. What should you expect under these circumstances?

•The target true course vector will be in error.

118. What will cause the ARPA to emit a visual alarm, audible alarm, or both?

•A tracked target entering your preset CPA-TCPA limits

119. What is the major component of a radar system which amplifies the weak echoes received thus retaining its distinct shapes?

•Indicator

120. According to Rule 19 of the COLREGs, what must be your action if you get into a close quarters situation with a vessel forward of the beam in restricted visibility?

•Reverse your engine until all way is lost.

121. An indirect radar echo is caused by a reflection of the main lobe of the radar beam of the observer's vessel. Which of the following is a characteristics of indirect echoes?

•Their bearing is almost constant, even when the true bearing of the contact changes appreciably.

122. What is the best way to monitor the risk of collision in poor visibility?

•Monitor the radar display and post a look-out

123. In radar principle, what determines the number of pulses that strike a target?

•The scanner rotational speed, aperture size of the aerial & PRF of the transmitter

124. What should be recorded in the radar log?

•The details of repairs and services carried out.

125. Which of the following ARPA data should you use in order to determine if a close quarter situation will develop with a target vessel?

•Relative track information

126. The radar has display has sectors of solid video (spoking). What woud be the first thing to check?

•For interference from nearby ships.

127. What is the radar control used to reduce sea return at close ranges?

•Sensitivity time control

128. What is the maximum number of minutes you should wait until utilizing ARPA data for collision avoidance decision making?

•3 minutes

129. Regarding the performance standards for navigational radar, what are the requirements for a scanner?

•It should rotate at a constant RPM of not less than 12 in relative wind speed up to 100 knots

130. What happens to the tracking accuracy of an ARPA as the range increases?

•Decreases

131. For all ships/crafts of 500 gross tonnage and upwards but less than 10,000 gross tonnage, what is the radar minimum operational display area in the performance requirements?

•250 mm

132. When using a radar in an unstabilized mode, how can you determine fixes easily?

•From ranges

133. Performance standards should apply to all shipborne radar installations, used in any configuration, mandated by the 1974 SOLAS Convention, as amended by the following EXCEPT:

•Back up arrangements

134. What is the minimum display area diameter in the performance requirements for all ships/crafts greater than 10,000 gross tonnage?

•340 x 340 mm

135. What is the two most important pieces of input information required to operate the ARPA?

•Speed and heading

136. Which type of radar do most ship's commonly operates?

•X-Band

137. What is the common radar frequency ranges of bands used in coastal radar systems?

•3-30 MHz

138. What is a radar display in which North is always at the top of the screen?

•Stabilized display

139. What is the best land target to use for a radar bearing?

•A small isolated feature.

140. What is the minimum sleeping target capacity of an ARPA?

•200 targets

141. Which general statement concerning radar is FALSE?

•The ability of radar to detect objects is unaffected by weather conditions

142. What purpose is the function "Brilliance/ Intensity/Brightness" on the radar?

•Regulations of the light on PPI

143. Which of the following radar presentation feature is useful in radar pilotage?

•True motion

144. Your ARPA has been tracking a target and has generated the targets data. The radar did not receive a target echo on its last two scans due to the weather. What should you expect under these circumstances?

•The ARPA will generate data as if the target is still being tracked by radar.

145. Which determine the minimum range at which a target can be detected?

•Pulse length

146. What purpose has the function "Brilliance / Intensity / Brightness" on the radar?

•Regulations of the light in PPI

147. What should you do in order to ensure that the Racon signal is visible on your 3 cm radar?

•Rain clutter control should be off, when necessary may be on low.

148. Which is the MOST correct statement containing the parameters which control the size of radar target echo?

•Transmitted power, antenna effective area, transmit and receive losses, RADAR cross section of the target, range to target.

149. The RADAR display has sectors of solid video (spoking). What would be the first thing to check?

•For interference from nearby ships.

150. When is the transmitted signal of the SART will be most conspicuous on the radar screen?

•When the receiver is not fined tuned

151. An estimated point in which of the distance between two objects of which at least one is in motion will reach a minimum value?

•Closest Point of Approach

152. What is the purpose of the function "Änticlutter" sea on the radar?

•Reduce the sea echoes

153. What is the average range of a ship's surface search radar unit?

•40 n miles

154. Ground stabilizing of the ARPA display using auto drift (echo reference) can be problematic due to the following EXCEPT:

•Bearing resolution

155. When can you determine the closest point of approach (CPA) of a contact on a relative motion radar?

•After the contact has been marked at least twice.

156. What are the advantages of manually acquiring ARPA targets?

•Operaqtor can control the number of the acquired targets

157. What is the radar control that reduces weak echoes out to a limited distances from the ship?

•Sensitivity time control sea clutter conntrol)

158. Which of the following controls is provided to check overall efficiency of the radar?

•Performance monitor

159. When two ships are on reciprocal courses, what is meant by the "approaching vessel's relative speed"?

•The sum of the speed of the two vessels

160. What are the four elements of a Radar system?

•Transmitter, antenna, receiver and display

161. What is the main reason that you will adjust the anti-clutter SEA control during boisterous weather?

•To reduce heavy sea echoes

162. What type of target would give the best radar echo?

•A 600-foot freighter beam on

163. You have another ship overtaking you close aboard to starboard. You have three radar targets bearing 090°, relative ranges 0.5 nm, 1 nm and 1.5 nm. In this case, what do you call the unwanted echoes?

•Multiple echoes

164. Your power-driven vessel is fitted with radar and is underway in poor visibility. At what speed should you proceed?

•A safe speed

165. If a target is 5 miles away, how long does it take for the radar echo to be received back at the antenna?

•61.70 microseconds

166. How many Radar Transponders (SART) are required to be carried onboard a ship for use in survival crafts?

•2 on new-builds only. Old ships have to comply by August-95

167. When using the radar in heavy rain what appropriate action should you take?

•Navigate as though the effective range of the radar had been reduced.

168. What caused the presentation of coral atolls or a chain of islands as long line rather than as individual targets ?

•The effects of beam width

169. What is the difference between a 10-cm radar compared to a 3-cm radar?

•A wider horizontal beam width

170. What facts show that an operator should carry out an operational check when a radar set is installed?

•To determine the limits of shadow sectors.

171. What is the minimum acquired radar target capacity in the performance requirements for all ships/crafts of less than 500 gross tonnage?

•20

172. Which of the following condition will happen if you turn on the fast time constant differentiator control on the radar?

•There is a better appearance definition

173. If your vessel, while proceeding East at 10 knots, observed by a radar a vessel proceeding West at 10 knots, what would be the approximate direction and rate at which the pip would move on your PPI scope?

•West at 20 knots

174. By what reason that edges of land should be avoided if possible when position fixing by radar.

•Their poor definition.

175. How will a rough surface target likely to appear on the display?

•Give good echo at any aspect.

176. When you examine the RADAR, you notice that there is no target video in the center of CRT. The blank spots gets smaller in diameter as you increase the range scale. What operatorr front panel control could be misadjusted?

•Sensitivity time control (STC)

177. What is one good practice of a navigator fixing a vesel position by means of Radar?

•Can use radar information from one object to fix the position

178. Which of the following do radar bearing discrimination depends mainly on?

•Horizontal beamwidth

179. What is the process of calculating target motion based on past positions by an ARPA?

•Smoothing

180. In fog, you observe your radar and determine that risk of collision exists with a vessel which is 2 miles of your port bow. Which action should you take?

•Take avoiding action as soon as possible

181. What does a low HDOP (Horizontal Dillution of Precision) number such as 2 indicates?

•Good fix

182. During navigation while ARPA running, you have the option to have two guard zones at the same time. What is the purpose of the inner guard zone?

•To give warning on small targets that are not initially detected by the outer guard zone.

183. The speed log input to your ARPA is in error, showing your vessel's speed to be 5 knots less than the actual speed. What would you expect under these circumstances?

•A target on a reciprocal course to own ship will show a speed that is too high and a target on the same course as own ship will show a true speed that is too low.

184. What will happen to the power of radar beam as distance from the scanner increases?

•Decreases rapidly

185. Which vector generated by ARPA has greater likelihood of errors ?

•True vector

186. Which vector generated by ARPA has greater likelihood of errors?

True vector

187. Ground stabilization of the ARPA is achieved through the following EXCEPT:

•Range resolution

188. What is the minimum acquired radar target capacity in the performance requirements for all ships/crafts greater than 10,000 gross tonnage?

•40

189. What is the typical figure for minimum radar range?

•25 meters

190. What should be the size of the display on which ARPA information with alphanumerical data area around it is presented?

•Display diameter should be at least 340 mm

191. What ratio would be used by a typical ARPA before writing a target into the final switch register?

5 returns to 10 pulses

192. Your radar displayed your ship off center. As you proceed on your course, your ships marker moves on the PPI scope while echoes from land masses remain stationary. What do you call this kind of display?

•True motion

193. Given the alteration of your own ship's course or speed required, from where can the desired Closest Point of Approach (CPA) be obtained?

•Radar plot

194. Identify the target that would give the best radar echo.

•A 600-foot freighter beam on

195. Which of these control is provided to check the overall efficiency of the radar?

•Performance monitor

196. How long must an ARPA produce a relative motion display with 95% accurate CPA/TCPA?

•Within 1 minute

197. In calm and clutter-free conditions, what is the minimum detection range for S-band radar if the target is a 4-meter tall small vessel with radar reflector meeting IMO Performance Standards?

•3.7 nm

198. Why should you carry out an operational check when a radar set is installed?

•To check the accuracy of the heading marker

199. An X band RADAR operates in which frequency band?

•8 - 12 GHz

100

200. If the radar antenna operates at 60 RPM, how long for a typical ARPA will generate a target vector?

•15 seconds

C1 - Plan and conduct a passage and determine position (200)

Joedz Padin · 100問 · 2年前

C1 - Plan and conduct a passage and determine position (200)