VOLUME 5-NAVIGATION SYSTEMS CH 1 & CH 2

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

(a) 3 spare (b) 21 active operational

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

0.25 miles

How many aircraft can be provided distance data simultaneously? 1. 25 2. 50 3. 75 4. 100

100

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

1227.60 MHz

. What is the total number of TACAN channels available using both X and Y modes? 1. 68 2. 100 3. 126 4. 252

126

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

15 seconds

How many earth orbits will each GPS satellite complete in a 24-hour period? 1. One 2. Two 3. Three 4. Four

2

In the AS-3240 electronically- scanned antenna, the old singlephase rotating parasitic element has been replaced by how many electronically-switched inner parasitic elements? 1. 6 2. 12 3. 24 4. 32

32

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

4

To obtain the above accuracy, how many satellite inputs are required? 1. Five 2. Two 3. Three 4. Four

4

Within how many feet can GPS determine position fixes? 1. 50 2. 250 3. 500 4. 1000

50 or less

The TACAN receiver frequency is always displaced how many MHz from the transmitter frequency? 1. 20 2. 42 3. 63 4. 75

63

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

A common time base

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

AN/PSN-8

What is the designation of latest TACAN equipment in the fleet? 1. AN/URN-25 2. AN/URN-20 3. AN/URN-15 4. AN/URN-10

AN/URN-25

Which of the following is a standalone SINS? 1. AN/WSN-5 2. AN/WSN-25 3. AN/WRN-6 4. AN/WRN-8

AN/WSN-5

What device measures changes in speed or direction along the axis in which it lies? 1. Gyroscope 2. Accelerometer 3. Axilometer 4. Servoscope

Accelerometer

Tropospheric delay is predicted and included in what satellite data? 1. Bias 2. Almanac 3. Variable 4. Precision

Almanac

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

Almanac and Ephemeris

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

Antenna height

Instead of depending on radio-wave reflection, beacon-transponders generate what type of replies? 1. Neutral 2. Artificial 3. Basic 4. Torque

Artificial

What is the common name of the 135-Hz reference burst? 1. Composite burst 2. North reference burst 3. Auxillary reference burst 4. East reference burst

Auxillary reference burst

CHAPTER 2

CHAPTER 2

What type of radiation pattern is transmitted by the TACAN ground station antenna? 1. Parabolic 2. Cardioid 3. Vectorial 4. Tangential

Cardioid

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

Clock

NNSS satellite refined orbits are calculated at which of the following facilities? 1. Tracking station 2. Control station 3. Computer center 4. Injection station

Computer center

LORAN takes advantage of what radio signal characteristic? 1. Constant amplitude 2. Constant velocity 3. Constant phase 4. Constant volume

Constant velocity

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

Control center

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

Directly proportional

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

Eight

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

Every 2 hours

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

Every 2 minutes

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

Every 24 hours

How often is the identification code broadcast? 1. Every 37.5 seconds 2. Every 60 seconds 3. Every 37.5 minutes 4. Every 60 minutes

Every 37.5 seconds during the transmission of an identification code dot or dash

Tactical navigation is directly concerned with maneuvering the ship in navigable waters. 1. True 2. False

False

The nominal orbit of NNSS satellites is what type of orbital parameter? 1. Status 2. Command 3. Systems 4. Fixed

Fixed

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

Fixed and variable

What signal does the TACAN ground station transmit to identify itself? 1. Identification pulse group 2. Voice pulse group 3. Triangulation pulse group 4. Burst pulse group

Identification pulse group

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

It decreases

What is one big advantage the electronically-scanned antenna has over the old mechanically-rotated antenna? 1. It eliminates bandwidth limitations 2. It is cheaper to build 3. It is easier to troubleshoot 4. It eliminates propagation effects

It eliminates bandwidth limitations

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

Line-of-sight

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

Manned control center

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

Multipath

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

NAVSTAR

What navigational system will replace the NNSS? 1. NAVSTAR GPS 2. OMEGA MK2 3. LORAN D 4. NNSS MK2

NAVSTAR GPS

Which of the following is the normal operating mode of the AN/WRN-6(V)? 1. Initialization 2. Test 3. Navigation 4. Tracking

Navigation

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

Piloting / Electronic navigation is a form of piloting

TACAN is based on what type of radio air-navigation system? 1. Polar-coordinate 2. Polar-sync 3. Neutral-coordinate 4. Neutral-sync

Polar-coordinate

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

Precise code

What type of modulation is used to convey TACAN bearing information? 1. Frequency 2. Pulse 3. Continuous wave 4. Amplitude modulation

Pulse

Which of the following factors affects the measurement of Doppler shift? 1. Refraction 2. Reflection 3. Reduction 4. Reproduction

Refraction

Which navigation system continually computes the latitude and longitude of a ship by sensing acceleration? 1. NAVSTAR 2. OMEGA 3. MILSTAR 4. SINS

SINS

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

SINS

. GPS navigation is based on what principle? 1. Satellite ranging 2. Satellite speed 3. Satellite broadcast 4. Satellite response

Satellite ranging

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

Seeing the landmarks

What type of system is used to keep a SINS platform stabilized? 1. Servo 2. Synchro 3. Gyro 4. Turbo

Servo

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

Space-based systems Terrestrial systems

Which of the following data is NOT included in the GPS NAV-msg? 1. Clock-bias 2. Correction data 3. Ephemeris 4. Spectral

Spectral

What communications technique is used for GPS satellite broadcasts? 1. Spontaneous-emission 2. Spread-spectrum 3. Standard-broadcast 4. Spectral-emission

Spread-spectrum

Which of the following receiver controls provides noise-generated output? 1. Fidelity 2. Sensitivity 3. Cycle 4. Squitter

Squitter

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

Sunspots

At what point will compression effects cause the received frequencies to be higher than the transmitted frequencies? 1. T1 2. T2 3. T3

T1

At what point will the received frequencies exactly match the transmitted frequencies? 1. T1 2. T2 3. T3

T2

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

T3

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

Time and date

What characteristic of the transmitted TACAN pulses supplies the distance information to aircraft? 1. Amplitude 2. Frequency 3. Timing 4. Gain

Timing

A ship's inertial navigation system is dependent on celestial, sight,and radio navigation aids. 1. True 2. False

True

Ionospheric delay is greatest when a signal is received from directly overhead. 1. True 2. False

True

NNSS satellite data can be used as an accurate time reference. 1. True 2. False

True

The AN/URN-20 uses the same electronically-scanned antenna as the AN/URN-25. 1. True 2. False

True

What type of decoders do TACAN transponders use? 1. Twin-pulse 2. Single-pulse 3. Neutral-pulse 4. Basic-pulse

Twin-pulse

NNSS satellites transmit phase modulated data every 2 minutes on how many rf carriers? 1. One 2. Two 3. Three 4. Four

Two

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

Two

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

Vessel's spee

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

dead reckoning

If more interrogating aircraft come into the TACAN'S range, the number of noise-generated pulses will 1. increase 2. decrease

decrease