Navedtra 14090 Electronics Technician Volume 05 Navigation Systems Chapter 1

Front 1

NAVEDTRA 14090
ELECTRONICS TECHNICIAN VOLUME 05
NAVIGATION SYSTEMS
CHAPTER 1

Back 1

NAVEDTRA 14090
ELECTRONICS TECHNICIAN VOLUME 05
NAVIGATION SYSTEMS
CHAPTER 1

Front 2

Tactical navigation is directly
concerned with maneuvering the ship
in navigable waters. TRUE OR FALSE.

Back 2

1. True
2. False

Front 3

Estimating ship’s position between
known navigational points or fixes
is known as

Back 3

1. ship maneuvering
2. dead reckoning
3. ship reckoning
4. dead maneuvering

Front 4

Radio navigation consists of which
of the following categories?

Back 4

1. Sub-space systems
2. Space–based systems
3. Terrestrial systems
4. Both 2 and 3 above

Front 5

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?

Back 5

1. It increases
2. It decreases
3. It stays the same
4. It fluctuates

Front 6

Referring to landmarks with known
positions on earth describes which
one of the following navigation
methods?

Back 6

1. Celestial
2. Charting
3. Dead reckoning
4. Piloting

Front 7

Which of the following actions
required to determine position in
piloting is/are not required in
electronic navigation?

Back 7

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

Front 8

According to the 1992 Federal Radio
Navigation Plan, which of the
following systems will become the
primary reference navigation system
for surface ships?

Back 8

1. LORAN
2. OMEGA
3. NAVSTAR
4. TACAN

Front 9

LORAN takes advantage of what radio
signal characteristic?

Back 9

1. Constant amplitude
2. Constant velocity
3. Constant phase
4. Constant volume

Front 10

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?

Back 10

1. A common receiver
2. A common signal shift
3. A common time base
4. A common transmitter

Front 11

Which navigation system continually
computes the latitude and longitude
of a ship by sensing acceleration?

Back 11

1. NAVSTAR
2. OMEGA
3. MILSTAR
4. SINS

Front 12

A ship’s inertial navigation system
is dependent on celestial, sight,
and radio navigation aids. TRUE OR FALSE?

Back 12

1. True
2. False

Front 13

What device measures changes in
speed or direction along the axis
in which it lies?

Back 13

1. Gyroscope
2. Accelerometer
3. Axilometer
4. Servoscope

Front 14

What type of system is used to keep
a SINS platform stabilized?

Back 14

1. Servo
2. Synchro
3. Gyro
4. Turbo

Front 15

Which of the following is a standalone
SINS?

Back 15

1. AN/WSN-5
2. AN/WSN–25
3. AN/WRN-6
4. AN/WRN-8

Front 16

Approximately how often can
operators using the NNSS obtain
fixes?

Back 16

1. Every hour
2. Every 2 hours
3. Every 3 hours
4. Every 4 hours

Front 17

NNSS satellites transmit phase
modulated data every 2 minutes on
how many rf carriers?

Back 17

1. One
2. Two
3. Three
4. Four

Front 18

What are the two types of NNSS
satellite parameters included in
the phase-modulated data?

Back 18

1. Systems and command
2. Terrestrial and space
3. Status and update
4. Fixed and variable

Front 19

The nominal orbit of NNSS
satellites is what type of orbital
parameter?

Back 19

1. Status
2. Command
3. Systems
4. Fixed

Front 20

NNSS satellite data can be used as
an accurate time reference. TRUE OR FALSE?

Back 20

1. True
2. False

Front 21

NNSS satellite refined orbits are
calculated at which of the
following facilities?

Back 21

1. Tracking station
2. Control station
3. Computer center
4. Injection station

Front 22

Which of the following facilities
calculates NNSS satellite clock
error before satellite message
injection?

Back 22

1. Control center
2. Computer center
3. Tracking station
4. Injection station

Front 23

Approximately how long does it take
the injection station to transmit
information to an NNSS satellite?

Back 23

1. 10 seconds
2. 12 seconds
3. 15 seconds
4. 18 seconds

Front 24

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?

Back 24

1. Every 20 seconds
2. Every 2 minutes
3. Every 2 hours
4. Every 12 hours

Front 25

At what point during the satellite
pass will expansion effects cause
the received frequencies to drop
below the generated frequencies?

Back 25

1. T1
2. T2
3. T3

Front 26

At what point will the received
frequencies exactly match the
transmitted frequencies?

Back 26

1. T1
2. T2
3. T3

Front 27

At what point will compression
effects cause the received
frequencies to be higher than the
transmitted frequencies?

Back 27

1. T1
2. T2
3. T3

Front 28

Which of the following factors
affects the measurement of Doppler
shift?

Back 28

1. Refraction
2. Reflection
3. Reduction
4. Reproduction

Front 29

To solve the problem of Doppler
shift accuracy, satellites are
designed to transmit on how many
frequencies?

Back 29

1. One
2. Two
3. Three
4. Four

Front 30

Accurate NNSS position fixes for a
moving vessel require what
additional computation?

Back 30

1. Vessel’s draft
2. Vessel’s length
3. Vessel’s speed
4. Vessel’s class

Front 31

Which ship’s system will provide
the information required to perform
the additional computation required
by NNSS?

Back 31

1. OMEGA
2. LORAN
3. PNNS
4. SINS

Front 32

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?

Back 32

1. Skip zone
2. Line–of–sight
3. Scatter zone
4. Line-of-support

Front 33

One of the capabilities of the
AN/WRN-5 includes time-ordered
alerts for up to how many
satellites?

Back 33

1. Six
2. Two
3. Eight
4. Four

Front 34

What is the “at sea” accuracy of
the AN/SRN-19(V)2?

Back 34

1. 0.25 feet
2. 0.25 meters
3. 0.25 miles
4. 0.25 kilometers

Front 35

What activity may degrade the
accuracy of the AN/SRN-19(V)2?

Back 35

1. Ship’s maneuvers
2. Sunspots
3. Rain
4. High sea state

Front 36

You are initializing the AN/SRN–
19(V)2. In addition to programing
the set’s position, what other
parameter must you enter?

Back 36

1. Antenna height
2. Ship’s length
3. Usable power
4. Cabling length

Front 37

What navigational system will
replace the NNSS?

Back 37

1. NAVSTAR GPS
2. OMEGA MK2
3. LORAN D
4. NNSS MK2

Front 38

Which of the following terms
describe GPS satellite positioning
data?

Back 38

1. Update and status
2. Variable and fixed
3. Daily and hourly
4. Almanac and ephemeris

Front 39

How often is the GPS satellite
navigation data message updated?

Back 39

1. Every hour
2. Every 12 hours
3. Every 24 hours
4. Every 36 hours

Front 40

What facility transmits the data
required to update the GPS
satellite navigation data message?

Back 40

1. Manned control center
2. Manned tracking station
3. Unmanned monitor station
4. Unmanned injection station

Front 41

There are how many (a) active spare
and (b) active operational GPS
satellites?

Back 41

1. (a) 21 (b) 3
2. (a) 3 (b) 21
3. (a) 3 (b) 24
4. (a) 24 (b) 21

Front 42

How many earth orbits will each GPS
satellite complete in a 24–hour
period?

Back 42

1. One
2. Two
3. Three
4. Four

Front 43

What communications technique is
used for GPS satellite broadcasts?

Back 43

1. Spontaneous–emission
2. Spread–spectrum
3. Standard–broadcast
4. Spectral–emission

Front 44

GPS satellites are positioned so a
minimum of how many satellites are
observable to a user anywhere on
earth?

Back 44

1. One
2. Two
3. Three
4. Four

Front 45

Which of the two codes (C/A and P)
transmitted by GPS satellites is
NOT available to civilian users?

Back 45

1. Course acquisition code
2. Precise code

Front 46

Which of the following data is
NOT included in the GPS NAV–msg?

Back 46

1. Clock–bias
2. Correction data
3. Ephemeris
4. Spectral

Front 47

GPS navigation is based on what
principle?

Back 47

1. Satellite ranging
2. Satellite speed
3. Satellite broadcast
4. Satellite response

Front 48

Within how many feet can GPS
determine position fixes?

Back 48

1. 50
2. 250
3. 500
4. 1000

Front 49

To obtain the above accuracy, how
many satellite inputs are required?

Back 49

1. Five
2. Two
3. Three
4. Four

Front 50

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?

Back 50

1. Inversely proportional
2. Directly proportional

Front 51

GPS satellites use atomic clocks;
the receivers do not. What type of
error must be computed based on
this fact?

Back 51

1. Delay
2. Eccentricity
3. Modulation
4. Clock

Front 52

Tropospheric delay is predicted and
included in what satellite data?

Back 52

1. Bias
2. Almanac
3. Variable
4. Precision

Front 53

Ionospheric delay is greatest when
a signal is received from directly
overhead.

Back 53

1. True
2. False

Front 54

Of the frequencies listed below,
which one will ionospheric delay
phase–shift the most?

Back 54

1. 1227.60 MHz
2. 1575.42 MHz
3. 1883.65 MHz
4. 2879.23 MHz

Front 55

Satellite signals reflecting off
one or more objects before reaching
the navigation set produce what
type of reception?

Back 55

1. Multipath
2. Faded
3. Skip-zone
4. Ground-wave

Front 56

What data do operators enter into
the AN/WRN-6(V) to speed up
satellite acquisition?

Back 56

1. Satellite type
2. Time and date
3. Current position
4. Both 2 and 3 above

Front 57

Which of the following is the
normal operating mode of the
AN/WRN-6(V)?

Back 57

1. Initialization
2. Test
3. Navigation
4. Tracking

Front 58

Which of the following is a
portable GPS receiver?

Back 58

1. AN/WRN–6
2. AN/WSN-5
3. AN/PSN–8
4. AN/SPA-2