Navigation 6 RADAR ARPA EXERCISE
- 1. 1. The word “RADAR” is derived from the phrase: a. Ranging Detection and Radio b. Radio Detection and Ranging c. Detection Ranging and Radio d. Detection Radio and Ranging 2. A short burst of electromagnetic energy transmitted and hit to an objectand then return. a. Radiowave b. Wavelength c. RADAR d. Frequency 3. An Electromagnetic Waves motion consistof crest and through. a. Wavelength b. RADAR c. Frequency d. Radiowave 4. A distance between a successive crestofwaves. a. Radiowave b. Frequency c. Wavelength d. RADAR 5. Another way ofmeasure of waves motion, which indicates the number ofcrest that pass a fix of initial time. a. RADAR b. Radiowave c. Frequency d. Wavelength 6. Transmit and receive in an concentrated beam and a motor turns the antenna in rotation, the signal, which are amplified the signal becomes visible to the operator in form of a radar picture. a. Antenna b. Display c. Receiver d. Transmitter 7. A radar echoes are display in a cathode ray tube (CRT). Several types ofCRT are utilized like A- SCAN or Short PersistentTube, Plan Position Indicator or PPI, Raster Scan Display. a. Antenna b. Display c. Receiver d. Transmitter 8. The incoming signal is fed to a series ofamplifier and further to detector demodulator for which smoothes the signal, the main task ofthe receiver is to amplify the reflected (incoming echoes) weak echoes and make them suitable for transmission to the indicator. a. Antenna b. Display c. Receiver d. Transmitter 9. It is the trigger pulses to the modulator and converted the inputs into a high frequency oscillation thru magnetron. A high frequency oscillation are fed via wave guide or into a coaxial cable to the transmitter/receiver switch. a. Antenna b. Display c. Receiver d. Transmitter 10. Is a long persistenttube, the trace is rotated around in unison with the rotation of the scanner and echoes previously recorded are retained during a period ofatleast one scanner revolution. a. PPI display
- 2. b. Raster Scan c. Radar Scan d. Radar Sweep 11. Normally a rectangular screen with dimension in the ratio 4:3 consisting of; example 1024 horizontal lines and 1280 vertical line or picture elements (pixel) a. PPI display b. Raster Scan c. Radar Scan d. Radar Sweep 12. It is a one complete 360 degrees rotation ofthe antenna (during one scan normally thousand sweeps are generated and transmitted). a. PPI display b. Raster Scan c. Radar Scan d. Radar Sweep 13. Is the transmission of one radar pulse only. a. PPI display b. Raster Scan c. Radar Scan d. Radar Sweep 14. Means more power and longer range butless resolution in range. a. Long Pulse b. Short Pulse c. PRF d. Radar Sweep 15. Means a weaker pulse, less radar range butbetter resolution in range. a. Long Pulse b. Short Pulse c. PRF d. Radar Sweep 16. Define as the number of pulses transmitted per second. a. Long Pulse b. Short Pulse c. PRF d. Radar Sweep 17. The ability of radar to discriminate between two small objects close together in the same bearing. a. Range Discrimination b. Bearing Discrimination c. Magnetic Compass d. Radiation 18. The ability of radar to discriminate between two small objectclose together atthe same range but different bearing. a. Range Discrimination b. Bearing Discrimination c. Magnetic Compass d. Radiation 19. The master compass on all ships and thus should be taken good care of. a. Range Discrimination b. Bearing Discrimination c. Magnetic Compass d. Radiation 20. Marine radar transmits energy of varying strength in form of short pulses or bursts. a. Range Discrimination b. Bearing Discrimination c. Magnetic Compass d. Radiation
- 3. 21. Temperature end humidity will increase with altitude and the radar wave will bend upwards; decreasing the radar range is called: a. Sub-Refraction b. Ducting c. Radar Blackout d. Sea Clutter 22. When radar beam is reflected several times between the fog and sea surface. The radar range can be increased considerably. a. Sub-Refraction b. Ducting c. Radar Blackout d. Sea Clutter 23. If the heightof the fog is less that the height ofthe radar antenna, a total reflection ofthe radar signal from the top ofthe fog may take place. a. Sub-Refraction b. Ducting c. Radar Blackout d. Sea Clutter 24. Are caused by reflection ofthe radar pulse againstthe sea waves. The reflection is spectacular and conditions for the pulse to return to the scanner are favorable near the ship. a. Sub-Refraction b. Ducting c. Radar Blackout d. Sea Clutter 25. The radar waves transmit in a straight line. A radar coastline echo (or any other objects) appearance will be determined by the topography.The radar picture can be quite different from the map. a. Radar Shadow b. Radar Reflector c. Radar Beacons d. Radar Picture 26. The ____________ is a plain picture of the ships surroundings. a. Radar Shadow b. Radar Reflector c. Radar Beacons d. Radar Picture 27. The purpose ofradar reflector is to directas much as possible ofthe reflected radar energy back to the radar antenna, which means stronger echoes on the PPI. a. Radar Shadow b. Radar Reflector c. Radar Beacons d. Radar Picture 28. Racon signal appears in PPIand provides bearing and range oftarget. a. Radar Shadow b. Radar Reflector c. Radar Beacons d. Radar Picture 29. Can be created by reflection between own ship and an objectbefore the scanner finally collects its energy. a. Multiple Echoes b. Side Echoes c. False Echoes d. Blind Sectors 30. Nearby target are picked up by the side lobes as well as by the main lobe. a. Multiple Echoes b. Side Echoes c. False Echoes
- 4. d. Blind Sectors II. Illustrate the following symbols for radar control. (2pts. each) 1. Radar Off 2. Radar On 3. Radar Stand By 4. Aerial Rotating 5. North-up Presentation 6. Head-up Presentation 7. Heading Marker Alignment 8. Range Selector 9. Short Pulse 10. Long Pulse 11. Gain 12. Gain 13. Anti Clutter Rain Minimum 14. Anti Clutter Rain Maximum 15. Anti Clutter Sea Minimum 16. Anti Clutter Sea Maximum 17. Scale Illumination 18. Display Brilliance 19. Range Rings Brilliance 20. Variable Range Marker END