- •Textbook Series
- •Contents
- •1 Properties of Radio Waves
- •Introduction
- •The Radio Navigation Syllabus
- •Electromagnetic (EM) Radiation
- •Polarization
- •Radio Waves
- •Wavelength
- •Frequency Bands
- •Phase Comparison
- •Practice Frequency (
- •Answers to Practice Frequency (
- •Questions
- •Answers
- •2 Radio Propagation Theory
- •Introduction
- •Factors Affecting Propagation
- •Propagation Paths
- •Non-ionospheric Propagation
- •Ionospheric Propagation
- •Sky Wave
- •HF Communications
- •Propagation Summary
- •Super-refraction
- •Sub-refraction
- •Questions
- •Answers
- •3 Modulation
- •Introduction
- •Keyed Modulation
- •Amplitude Modulation (AM)
- •Single Sideband (SSB)
- •Frequency Modulation (FM)
- •Phase Modulation
- •Pulse Modulation
- •Emission Designators
- •Questions
- •Answers
- •4 Antennae
- •Introduction
- •Basic Principles
- •Aerial Feeders
- •Polar Diagrams
- •Directivity
- •Radar Aerials
- •Modern Radar Antennae
- •Questions
- •Answers
- •5 Doppler Radar Systems
- •Introduction
- •The Doppler Principle
- •Airborne Doppler
- •Janus Array System
- •Doppler Operation
- •Doppler Navigation Systems
- •Questions
- •Answers
- •6 VHF Direction Finder (VDF)
- •Introduction
- •Procedures
- •Principle of Operation
- •Range of VDF
- •Factors Affecting Accuracy
- •Determination of Position
- •VDF Summary
- •Questions
- •Answers
- •7 Automatic Direction Finder (ADF)
- •Introduction
- •Non-directional Beacon (NDB)
- •Principle of Operation
- •Frequencies and Types of NDB
- •Aircraft Equipment
- •Emission Characteristics and Beat Frequency Oscillator (BFO)
- •Presentation of Information
- •Uses of the Non-directional Beacon
- •Plotting ADF Bearings
- •Track Maintenance Using the RBI
- •Homing
- •Tracking Inbound
- •Tracking Outbound
- •Drift Assessment and Regaining Inbound Track
- •Drift Assessment and Outbound Track Maintenance
- •Holding
- •Runway Instrument Approach Procedures
- •Factors Affecting ADF Accuracy
- •Factors Affecting ADF Range
- •Accuracy
- •ADF Summary
- •Questions
- •Answers
- •8 VHF Omni-directional Range (VOR)
- •Introduction
- •The Principle of Operation
- •Terminology
- •Transmission Details
- •Identification
- •Monitoring
- •Types of VOR
- •The Factors Affecting Operational Range of VOR
- •Factors Affecting VOR Beacon Accuracy
- •The Cone of Ambiguity
- •Doppler VOR (DVOR)
- •VOR Airborne Equipment
- •VOR Deviation Indicator
- •Radio Magnetic Indicator (RMI)
- •Questions
- •In-flight Procedures
- •VOR Summary
- •Questions
- •Annex A
- •Annex B
- •Annex C
- •Answers
- •Answers to Page 128
- •9 Instrument Landing System (ILS)
- •Introduction
- •ILS Components
- •ILS Frequencies
- •DME Paired with ILS Channels
- •ILS Identification
- •Marker Beacons
- •Ground Monitoring of ILS Transmissions
- •ILS Coverage
- •ILS Principle of Operation
- •ILS Presentation and Interpretation
- •ILS Categories (ICAO)
- •Errors and Accuracy
- •Factors Affecting Range and Accuracy
- •ILS Approach Chart
- •ILS Calculations
- •ILS Summary
- •Questions
- •Answers
- •10 Microwave Landing System (MLS)
- •Introduction
- •ILS Disadvantages
- •The MLS System
- •Principle of Operation
- •Airborne Equipment
- •Question
- •Answer
- •11 Radar Principles
- •Introduction
- •Types of Pulsed Radars
- •Radar Applications
- •Radar Frequencies
- •Pulse Technique
- •Theoretical Maximum Range
- •Primary Radars
- •The Range of Primary Radar
- •Radar Measurements
- •Radar Resolution
- •Moving Target Indication (MTI)
- •Radar Antennae
- •Questions
- •Answers
- •12 Ground Radar
- •Introduction
- •Area Surveillance Radars (ASR)
- •Terminal Surveillance Area Radars
- •Aerodrome Surveillance Approach Radars
- •Airport Surface Movement Radar (ASMR)
- •Questions
- •Answers
- •13 Airborne Weather Radar
- •Introduction
- •Component Parts
- •AWR Functions
- •Principle of Operation
- •Weather Depiction
- •Control Unit
- •Function Switch
- •Mapping Operation
- •Pre-flight Checks
- •Weather Operation
- •Colour AWR Controls
- •AWR Summary
- •Questions
- •Answers
- •14 Secondary Surveillance Radar (SSR)
- •Introduction
- •Advantages of SSR
- •SSR Display
- •SSR Frequencies and Transmissions
- •Modes
- •Mode C
- •SSR Operating Procedure
- •Special Codes
- •Disadvantages of SSR
- •Mode S
- •Pulses
- •Benefits of Mode S
- •Communication Protocols
- •Levels of Mode S Transponders
- •Downlink Aircraft Parameters (DAPS)
- •Future Expansion of Mode S Surveillance Services
- •SSR Summary
- •Questions
- •Answers
- •15 Distance Measuring Equipment (DME)
- •Introduction
- •Frequencies
- •Uses of DME
- •Principle of Operation
- •Twin Pulses
- •Range Search
- •Beacon Saturation
- •Station Identification
- •VOR/DME Frequency Pairing
- •DME Range Measurement for ILS
- •Range and Coverage
- •Accuracy
- •DME Summary
- •Questions
- •Answers
- •16 Area Navigation Systems (RNAV)
- •Introduction
- •Benefits of RNAV
- •Types and Levels of RNAV
- •A Simple 2D RNAV System
- •Operation of a Simple 2D RNAV System
- •Principle of Operation of a Simple 2D RNAV System
- •Limitations and Accuracy of Simple RNAV Systems
- •Level 4 RNAV Systems
- •Requirements for a 4D RNAV System
- •Control and Display Unit (CDU)
- •Climb
- •Cruise
- •Descent
- •Kalman Filtering
- •Questions
- •Appendix A
- •Answers
- •17 Electronic Flight Information System (EFIS)
- •Introduction
- •EHSI Controller
- •Full Rose VOR Mode
- •Expanded ILS Mode
- •Full Rose ILS Mode
- •Map Mode
- •Plan Mode
- •EHSI Colour Coding
- •EHSI Symbology
- •Questions
- •Appendix A
- •Answers
- •18 Global Navigation Satellite System (GNSS)
- •Introduction
- •Satellite Orbits
- •Position Reference System
- •The GPS Segments
- •The Space Segment
- •The Control Segment
- •The User Segment
- •Principle Of Operation
- •GPS Errors
- •System Accuracy
- •Integrity Monitoring
- •Differential GPS (DGPS)
- •Combined GPS and GLONASS Systems
- •Questions
- •Answers
- •19 Revision Questions
- •Questions
- •Answers
- •Specimen Examination Paper
- •Appendix A
- •Answers to Specimen Examination Paper
- •Explanation of Selected Questions
- •20 Index
15 Questions
Questions
Questions 15
1.Airborne DME equipment is able to discriminate between pulses intended for itself and pulses intended for other aircraft because:
a.aircraft transmit and receive on different frequencies
b.aircraft will only accept unique twin pulses
c.aircraft reject pulses not synchronized with its own random pulse recurrence rate
d.each aircraft has its own frequency allocation
2.A DME beacon having a transmit frequency of 962 MHz would have a receive frequency of:
a.1030 Mhz
b.902 Mhz
c.1025 Mhz
d.962 Mhz
3.A VOR/DME share the same first two letters of their respective identifiers; the last identifying letter of the DME is a Z. This means that:
a.they are co-located
b.they are more than 600 m apart but serve the same location
c.they are widely separated and do not serve the same location
d.they are a maximum distance of 30 m apart
4. |
Distance Measuring Equipment is an example of ............... |
radar operating on a |
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frequency of ............... |
in the ................ |
band. |
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a. |
primary |
8800 MHz |
SHF |
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b. |
secondary |
1030 MHz |
UHF |
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c. |
secondary |
962 MHz |
UHF |
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d. |
primary |
9375 MHz |
SHF |
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5.A DME transponder does not respond to pulses received from radars other than DME because:
a.each aircraft transmits pulses at a random rate
b.DME transmits and receives on different frequencies
c.it will only accept the unique twin DME pulses
d.DME only responds to the strongest 100 interrogators
6.The range indicated by DME is considered to be accurate to within:
a.3% of range
b.1.25 % of range
c.0.5 NM
d.+/-0.25 NM +/-1.25% of range
254
Questions 15
7.A DME receiver is able to distinguish between replies to its own interrogations and replies to other aircraft because:
a.DME is secondary radar and each aircraft transmits and receives on a different frequency
b.DME transponders reply to interrogations with twin pulses and the airborne equipment ejects all other pulses
c.each aircraft transmits pulses at a random rate and will only accept synchronized replies
d.when DME is in the search mode it will only accept pulses giving the correct range
8.When a DME transponder becomes saturated:
a.it reverts to standby
b.it increases the number of pulse pairs to meet the demand
c.it increases the receiver threshold to remove weaker signals
d.it goes into a selective response mode of operation
9.An aircraft flying at FL250 wishes to interrogate a DME beacon situated 400 ft AMSL. What is the maximum range likely to be achieved?
a.210 NM
b.198 NM
c.175 NM
d.222 NM
10.For a DME and a VOR to be said to be associated it is necessary for: b. the DME to transmit on the same VHF frequency as the VOR
b.the aerial separation not to exceed 100 ft in a TMA or 2000 ft outside a TMA
c.the aerial separation not to exceed 100 m in a TMA or 2000 m outside a TMA
d.both beacons to have the same first two letters for their ident but the last letter of the DME to be a ‘Z’
11.The transmission frequency of a DME beacon is 63 MHz removed from the aircraft interrogator frequency to prevent:
a.interference from other radars
b.the airborne receiver locking on to primary returns from its own transmissions
c.static interference
d.receiver accepting replies intended for other interrogators
12.The accuracy associated with DME is:
a.+ or - 3% of range, or 0.5 NM, whichever is greater
b.+ or - 1.25% of range
c.+ or - 3% of range
d.+/-0.25 NM +/-1.25% of range
Questions 15
255
15 Questions
13.For a VOR and a DME beacon to be said to be associated the aerial separation must not exceed ............... in a terminal area and ................ outside a terminal area.
a. |
100 m |
2000 m |
b. |
50 ft |
200 ft |
c. |
30 m |
600 m |
d. |
50 m |
200 m |
14.DME is a ............... radar operating in the ............... band and uses ................ in order to obtain range information. The correct words to complete the above statement are:
a. |
primary |
SHF |
CW signals |
b. |
secondary |
UHF |
twin pulses |
c. |
secondary |
SHF |
“jittered pulses” |
d. |
primary |
UHF |
pulse pairs |
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15. |
The receiver of airborne DME equipment is able to “lock on” to its own “reply pulses” |
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because: |
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a. |
each aircraft has its own unique transmitter frequency and the receiver only |
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accepts reply pulses having this frequency |
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b. |
the reply pulses from the ground transmitter have the same frequency as the |
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incoming interrogation pulses from the aircraft |
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c. |
the aircraft receiver only accepts reply pulses which have the same time interval |
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between successive pulses as the pulses being transmitted by its own transmitter |
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15 |
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d. |
the aircraft receiver only accepts reply pulses which arrive at a constant time |
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interval |
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Questions |
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16. |
the emission designator of ............... |
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DME operates in the ............... frequency band, it transmits ............... which give it |
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a. |
SHF |
double size pulses |
P01 |
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b. |
UHF |
twin pulses |
P0N |
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c. |
EHF |
twin pulses |
A9F |
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d. |
UHF |
double pulses |
J3E |
17.Referring to DME during the initial stage of the “search” pattern before “lock-on”:
a.the airborne receiver checks 150 pulses each second
b.the airborne transmitter transmits 150 pulses each second
c.the ground receiver maintains the ground transmitter pulse transmission rate at no more than 150 per second
d.the aircraft transmits 24 pulses per second and the receiver checks a maximum of 150 pulses per second
18.DME and VOR are “frequency paired” because:
a.the same receiver can be used for both aids
b.the VOR transmitter is easily converted to the required DME frequency
c.cockpit workload is reduced
d.both ground transmitter aerials can be placed on the same site if required
256
Questions 15
19.A DME receiver is able to distinguish between replies to its own interrogation pulses and those intended for other aircraft using the same transponder because:
a.DME is a secondary radar and each aircraft transmits and receives on a different frequency
b.DME transponders reply to interrogations by means of twin pulses and the airborne equipment rejects all single pulses
c.each aircraft transmits pulses at a random rate(“jittering”) and will only accept replies that match this randomization
d.when DME is in the range search mode it will accept only pulses separated by + or - 63 MHz from the interrogation frequency
Questions 15
257