Navedtra 14090 Et Volume 5 Chapter 1&2

Front 1

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

Back 1

Dead reckoning

Front 2

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 2

It decreases

Front 3

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

Back 3

Piloting

Front 4

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

Back 4

Seeing the landmarks

Front 5

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

Back 5

NAVSTAR

Front 6

LORAN rakes advantage of what radio signal characteristic?

Back 6

Constant velocity

Front 7

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 7

a common time base

Front 8

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

Back 8

SINS

Front 9

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

Back 9

Accelerometer

Front 10

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

Back 10

GYRO

Front 11

Which of the following is a standalone SINS?

Back 11

AN/WSN-5

Front 12

Approximately how often can operators using the NNSS obtain fixes?

Back 12

Every 2 hours

Front 13

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

Back 13

2

Front 14

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

Back 14

Fixed and variable

Front 15

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

Back 15

Fixed

Front 16

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

Back 16

Computer Center

Front 17

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

Back 17

Control Center

Front 18

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

Back 18

15 seconds

Front 19

If errors are detected during a read back of freshly injected satellite data, how often is NNSS satellite message injection repeated until the transmission is verified as being correct?

Back 19

Every 2 minutes

Front 20

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

Back 20

Refraction

Front 21

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

Back 21

2

Front 22

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

Back 22

Vessel's speed

Front 23

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

Back 23

SINS

Front 24

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 24

Line-of-sight

Front 25

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

Back 25

Eight

Front 26

What is the "at sea" accuracy of the AN/SRN-19(v)2?

Back 26

0.25 miles

Front 27

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

Back 27

Sunspots

Front 28

You are initializing the AN/SRN-19(v)2. In addition to programming the set's position, what other parameter must you enter?

Back 28

Antenna height

Front 29

What navigational system will replace the NNSS?

Back 29

NAVSTAR GPS

Front 30

Which of the following terms describe GPS satellite positioning data?

Back 30

Almanac and Ephemeris

Front 31

How Often is the GPS satellite navigation data message updated?

Back 31

Every 24 hours

Front 32

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

Back 32

Manned control center

Front 33

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

Back 33

(a)3 (b)21

Front 34

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

Back 34

Two

Front 35

What communications technique is used for GPS satellite broadcasts?

Back 35

Spread-spectrum

Front 36

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

Back 36

Four

Front 37

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

Back 37

Precise code

Front 38

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

Back 38

Spectral

Front 39

GPS navigation is based on what principle?

Back 39

Satellite ranging

Front 40

Whithin how many feet can GPS determine position fixes?

Back 40

50

Front 41

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

Back 41

Four

Front 42

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 42

Directly proportional

Front 43

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

Back 43

Clock

Front 44

Troposperic delay is predicted and included in what satellite data?

Back 44

Almanac

Front 45

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

Back 45

Multipath

Front 46

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

Back 46

Navigation

Front 47

Which of the following is a portable GPS receiver?

Back 47

AN/WRN-6

Front 48

TACAN is based on what type of radio air-navigation system?

Back 48

Polar-coordinate

Front 49

Instead of depending on radio-wave reflection, becaon-transponders generate what type of replies?

Back 49

Artificial

Front 50

What type of decoders do TACAN transponders use?

Back 50

Twin-pulse

Front 51

Which of the following receiver controls provides noise-generated output?

Back 51

Squitter

Front 52

If more interrogating aircraaft come into the TACAN's range, the number of noise generated pulses will____

Back 52

Decrease

Front 53

What signal does the TACAN ground station transmit to identify itself?

Back 53

Identification pulse group

Front 54

What characteristic of the transmitted TACAN pulses supplies the distance information to aircraft?

Back 54

Timing

Front 55

What type of modulation is used to convey TACAN bearing information?

Back 55

Amplitude modulation

Front 56

What type of radiation pattern is transmitted by the TACAN gound station antenna?

Back 56

Cardioid

Front 57

what is the common name of the 135-Hz reference burst?

Back 57

North reference burst

Front 58

How often is the identification code broadcast?

Back 58

Every 37.5 seconds

Front 59

What is the designation of latest TACAN equipment in the fleet?

Back 59

AN/URN-25

Front 60

In the AS-3240 electronically-scanned antenna, the old sigle phase rotating parasitic element has been replaced by how many electronically-switched inner parasitic elements?

Back 60

12

Front 61

What is one big advantage the electronically-scanned antenna has over the old mechanically-rotated antenna?

Back 61

It eliminates bandwidth limitations

Front 62

What is the total number of TACAN channels available using both X and Y modes?

Back 62

252

Front 63

the TACAN receiver frequency is always displaced how many MHz from the transmitter frequency?

Back 63

63

Front 64

How many aircraft can be provided distance data simultaneously?

Back 64

100