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58 Cards in this Set
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NAVEDTRA 14090
ELECTRONICS TECHNICIAN VOLUME 05 NAVIGATION SYSTEMS CHAPTER 1 |
NAVEDTRA 14090
ELECTRONICS TECHNICIAN VOLUME 05 NAVIGATION SYSTEMS CHAPTER 1 |
|
Tactical navigation is directly
concerned with maneuvering the ship in navigable waters. TRUE OR FALSE. |
1. True
2. False |
|
Estimating ship’s position between
known navigational points or fixes is known as |
1. ship maneuvering
2. dead reckoning 3. ship reckoning 4. dead maneuvering |
|
Radio navigation consists of which
of the following categories? |
1. Sub-space systems
2. Space–based systems 3. Terrestrial systems 4. Both 2 and 3 above |
|
One of the characteristics of dead
reckoning is that the accuracy of the estimated position never exceeds the navigation method used to obtain the last fix. What happens to the accuracy of the estimated position over time? |
1. It increases
2. It decreases 3. It stays the same 4. It fluctuates |
|
Referring to landmarks with known
positions on earth describes which one of the following navigation methods? |
1. Celestial
2. Charting 3. Dead reckoning 4. Piloting |
|
Which of the following actions
required to determine position in piloting is/are not required in electronic navigation? |
1. Seeing the landmarks
2. Determining the ship’s heading 3. Having the ship on a dead reckoned course 4. Both 2 and 3 above |
|
According to the 1992 Federal Radio
Navigation Plan, which of the following systems will become the primary reference navigation system for surface ships? |
1. LORAN
2. OMEGA 3. NAVSTAR 4. TACAN |
|
LORAN takes advantage of what radio
signal characteristic? |
1. Constant amplitude
2. Constant velocity 3. Constant phase 4. Constant volume |
|
OMEGA is a hyperbolic phase—
difference measuring system that compares the phase angle of two or more radio signals synchronized to what device or factor? |
1. A common receiver
2. A common signal shift 3. A common time base 4. A common transmitter |
|
Which navigation system continually
computes the latitude and longitude of a ship by sensing acceleration? |
1. NAVSTAR
2. OMEGA 3. MILSTAR 4. SINS |
|
A ship’s inertial navigation system
is dependent on celestial, sight, and radio navigation aids. TRUE OR FALSE? |
1. True
2. False |
|
What device measures changes in
speed or direction along the axis in which it lies? |
1. Gyroscope
2. Accelerometer 3. Axilometer 4. Servoscope |
|
What type of system is used to keep
a SINS platform stabilized? |
1. Servo
2. Synchro 3. Gyro 4. Turbo |
|
Which of the following is a standalone
SINS? |
1. AN/WSN-5
2. AN/WSN–25 3. AN/WRN-6 4. AN/WRN-8 |
|
Approximately how often can
operators using the NNSS obtain fixes? |
1. Every hour
2. Every 2 hours 3. Every 3 hours 4. Every 4 hours |
|
NNSS satellites transmit phase
modulated data every 2 minutes on how many rf carriers? |
1. One
2. Two 3. Three 4. Four |
|
What are the two types of NNSS
satellite parameters included in the phase-modulated data? |
1. Systems and command
2. Terrestrial and space 3. Status and update 4. Fixed and variable |
|
The nominal orbit of NNSS
satellites is what type of orbital parameter? |
1. Status
2. Command 3. Systems 4. Fixed |
|
NNSS satellite data can be used as
an accurate time reference. TRUE OR FALSE? |
1. True
2. False |
|
NNSS satellite refined orbits are
calculated at which of the following facilities? |
1. Tracking station
2. Control station 3. Computer center 4. Injection station |
|
Which of the following facilities
calculates NNSS satellite clock error before satellite message injection? |
1. Control center
2. Computer center 3. Tracking station 4. Injection station |
|
Approximately how long does it take
the injection station to transmit information to an NNSS satellite? |
1. 10 seconds
2. 12 seconds 3. 15 seconds 4. 18 seconds |
|
If errors are detected during a
readback of freshly injected satellite data, how often is NNSS satellite message injection repeated until the transmission is verified as being correct? |
1. Every 20 seconds
2. Every 2 minutes 3. Every 2 hours 4. Every 12 hours |
|
At what point during the satellite
pass will expansion effects cause the received frequencies to drop below the generated frequencies? |
1. T1
2. T2 3. T3 |
|
At what point will the received
frequencies exactly match the transmitted frequencies? |
1. T1
2. T2 3. T3 |
|
At what point will compression
effects cause the received frequencies to be higher than the transmitted frequencies? |
1. T1
2. T2 3. T3 |
|
Which of the following factors
affects the measurement of Doppler shift? |
1. Refraction
2. Reflection 3. Reduction 4. Reproduction |
|
To solve the problem of Doppler
shift accuracy, satellites are designed to transmit on how many frequencies? |
1. One
2. Two 3. Three 4. Four |
|
Accurate NNSS position fixes for a
moving vessel require what additional computation? |
1. Vessel’s draft
2. Vessel’s length 3. Vessel’s speed 4. Vessel’s class |
|
Which ship’s system will provide
the information required to perform the additional computation required by NNSS? |
1. OMEGA
2. LORAN 3. PNNS 4. SINS |
|
Given the orbital parameters of a
satellite, the Doppler shift of the signal transmitted from that satellite, and the velocity of a vessel, it is possible to obtain a navigational fix if the satellite is within what distance from the navigation set? |
1. Skip zone
2. Line–of–sight 3. Scatter zone 4. Line-of-support |
|
One of the capabilities of the
AN/WRN-5 includes time-ordered alerts for up to how many satellites? |
1. Six
2. Two 3. Eight 4. Four |
|
What is the “at sea” accuracy of
the AN/SRN-19(V)2? |
1. 0.25 feet
2. 0.25 meters 3. 0.25 miles 4. 0.25 kilometers |
|
What activity may degrade the
accuracy of the AN/SRN-19(V)2? |
1. Ship’s maneuvers
2. Sunspots 3. Rain 4. High sea state |
|
You are initializing the AN/SRN–
19(V)2. In addition to programing the set’s position, what other parameter must you enter? |
1. Antenna height
2. Ship’s length 3. Usable power 4. Cabling length |
|
What navigational system will
replace the NNSS? |
1. NAVSTAR GPS
2. OMEGA MK2 3. LORAN D 4. NNSS MK2 |
|
Which of the following terms
describe GPS satellite positioning data? |
1. Update and status
2. Variable and fixed 3. Daily and hourly 4. Almanac and ephemeris |
|
How often is the GPS satellite
navigation data message updated? |
1. Every hour
2. Every 12 hours 3. Every 24 hours 4. Every 36 hours |
|
What facility transmits the data
required to update the GPS satellite navigation data message? |
1. Manned control center
2. Manned tracking station 3. Unmanned monitor station 4. Unmanned injection station |
|
There are how many (a) active spare
and (b) active operational GPS satellites? |
1. (a) 21 (b) 3
2. (a) 3 (b) 21 3. (a) 3 (b) 24 4. (a) 24 (b) 21 |
|
How many earth orbits will each GPS
satellite complete in a 24–hour period? |
1. One
2. Two 3. Three 4. Four |
|
What communications technique is
used for GPS satellite broadcasts? |
1. Spontaneous–emission
2. Spread–spectrum 3. Standard–broadcast 4. Spectral–emission |
|
GPS satellites are positioned so a
minimum of how many satellites are observable to a user anywhere on earth? |
1. One
2. Two 3. Three 4. Four |
|
Which of the two codes (C/A and P)
transmitted by GPS satellites is NOT available to civilian users? |
1. Course acquisition code
2. Precise code |
|
Which of the following data is
NOT included in the GPS NAV–msg? |
1. Clock–bias
2. Correction data 3. Ephemeris 4. Spectral |
|
GPS navigation is based on what
principle? |
1. Satellite ranging
2. Satellite speed 3. Satellite broadcast 4. Satellite response |
|
Within how many feet can GPS
determine position fixes? |
1. 50
2. 250 3. 500 4. 1000 |
|
To obtain the above accuracy, how
many satellite inputs are required? |
1. Five
2. Two 3. Three 4. Four |
|
How is the time difference between
satellite transmission and when the navigation set receives this signal related to the distance between the satellite and the receiver? |
1. Inversely proportional
2. Directly proportional |
|
GPS satellites use atomic clocks;
the receivers do not. What type of error must be computed based on this fact? |
1. Delay
2. Eccentricity 3. Modulation 4. Clock |
|
Tropospheric delay is predicted and
included in what satellite data? |
1. Bias
2. Almanac 3. Variable 4. Precision |
|
Ionospheric delay is greatest when
a signal is received from directly overhead. |
1. True
2. False |
|
Of the frequencies listed below,
which one will ionospheric delay phase–shift the most? |
1. 1227.60 MHz
2. 1575.42 MHz 3. 1883.65 MHz 4. 2879.23 MHz |
|
Satellite signals reflecting off
one or more objects before reaching the navigation set produce what type of reception? |
1. Multipath
2. Faded 3. Skip-zone 4. Ground-wave |
|
What data do operators enter into
the AN/WRN-6(V) to speed up satellite acquisition? |
1. Satellite type
2. Time and date 3. Current position 4. Both 2 and 3 above |
|
Which of the following is the
normal operating mode of the AN/WRN-6(V)? |
1. Initialization
2. Test 3. Navigation 4. Tracking |
|
Which of the following is a
portable GPS receiver? |
1. AN/WRN–6
2. AN/WSN-5 3. AN/PSN–8 4. AN/SPA-2 |