EQPS Flashcards
How fast do radio waves travel?
300,000,000m per second
What is a cycle?
Wave travelling from 0, up and down back to 0
What is amplitude?
The maximum displacement or value attained by the wave from its mean value during a cycle
What is a Hertz?
1 oscillation/cycle
What is the frequency of a wave?
The rate of oscillation
What are the wavelengths for VHF?
1-10m
Equation for velocity:
Frequency x Wavelength
What use of radio waves is made in the provision of ATC?
Voice comms
Nav VOR/NDB
Surveillance systems
Weather radar
Data transfer
Advantages of FM:
Resilience to noise
Low power modulation
less battery power needed
What is attenuation?
A radio wave reducing in strength with range or time from the point of transmission
What is ducting?
refraction due to a temperature inversion
What are the common contents of a CPDLC message?
Flight levels
lateral deviations
route changes
clearances
routine delivery of messages
Advantages of AM:
ATC can override pilots
Heterodyne
What medium do we use for transmission of radar data?
Short distance Co-axial & Fibre optic
Long distances radio link
telephone link
What means do we use to communicate in ATC?
RTF
Direct controller to controller communication
Landlines
Interphone
intercom system
mobile phone
ATOTN
Air traffic operational telephone network
what is SELCAL?
Selective calling
RTF is replaced by ‘coded tones’ sent over RTF channels
What frequency does SELCAL use?
VHF and HF and code is found in flight plan
What is the AFS?
Aeronautical Fixed Service
A telecommunications service between specified fixed points provided primarily for the safety of air navigation and for the regular, efficient and economical operation of air services
What is MOTNE?
MET Operation Telecomms Network Europe
“A channel of AFS for the exchange of
aeronautical meteorological information”
What is OLDI?
Online Data Interchange
A protocol for co-ordination and transfer of current flight data between adjacent air traffic control units.
What is Radar?
Radio Detection and Ranging
How does radar work?
A pulse of electromagnetic energy reflects off an object
Which part of the Waveband spectrum is used by radar?
1mm - 100cm
What factors affect choice of Radar system?
Attenuation of particular wavelengths
Which wavelength is used for Primary approach?
3cm-10cm
Which wavelength is used for primary area radar?
23cm - 50cm
What causes clutter?
Ground objects
weather
What are the 3 basic blocks of a primary radar system?
Transmission
Reception
Display
How does the transmission block work?
Trigger unit sends a series of pulses to the modulator which is an ON/OFF switch for the transmitter, the transmitter sends a series of pulses to the aerial
How does the reception block work?
The signal reception block detects reflected signals and the boosted clean signal received is displayed on the situation display
What is PRI?
Pulse repetition interval
What factors affect radar coverage?
Attenuation
Ducting
Atmosphere
PRF
Transmitter power
Anaprop
Pulse length
How do we remove unwanted returns?
MTI
CP
What is tangental fade?
A target moving 90 degrees to radar beam
What signal does the ground transponder use to request information?
1030MHz
What signal is used by the airborne transponder to reply to an interrogation
1090MHz
What wavelength is used for SSR systems?
30cm
What modes are used for the SSR interrogator process?
Mode A for Ident
Mode C for Vertical info
How many transponder codes are available?
4096
What types of SSR codes can be issued?
Discrete
Non discrete
Special
Conspicuity
What is CCAMS?
Centralised code assignment and management system
What are Emergency codes?
7700- General emergency
7600- Radio Failure
7500- Unlawful Interference
What is Mode C?
The transmission of vertical position information is the response to an interrogation
What are the disadvantages of SSR?
Garbling
Fruiting
Antenna Shadowing
Factors determining Radar coverage? SSR
Aerial size and shape
Target size
Atmosphere
Transmitter power
Receiver efficiency
PRF
Pulse length
Operational Radar procedures are determined using which vertical coverage diagram?
UCD
What does mode S Elementary provide?
Position
Ident
Altitude
Mode S frequency band?
1030MHz and 1090MHz
Mode S Elementary allows what functionality?
24bit Ident on Mode A
25ft altitude reporting Mode C
What operational improvements will be made with enhanced Mode S?
datalink
automatic provision of airborne data
What are the safety benefits of EHS?
Early detection of A/C movement
Level busts
What are the capacity benefits of EHS?
Reduced workload
Direct up to date info to ATCO
Reduced RTF occupancy
What is Multi-radar processing?
Processing signals from disparate radar/surveillance sites
What items are depicted on a video map?
Significant points
Final approach tracks
airspace restrictions
CAS boundaries
Coastlines and rivers
What moveable data is available on radar?
ERBM
Curser
DF bearing
Alpha numeric
symbols
What is ADS?
A means by which aircraft and other objects can automatically transmit and or receive data such as identification, position and additional data , as appropriate, In broadcast mode via a data link
What info does ADS broadcast?
Horizontal position
vertical position
velocity
How can other aircraft make use of ADS data?
Use it in order to facilitate airborne traffic situational awareness, spacing and self separation
What are the primary types of ADS message?
position
identification
velocity
What are the 3 ‘On-event’ messages?
Trajectory
status
test
What is the maximum and minimum accuracy of a position report for ADS-B?
7.5nm
>20nm
what are the aircraft requirements?
GPS navigation
Mode-S transponder
Avionics capable of providing correct data
Correct connections between the three
What is ADS C?
C = Contract
MLAT questions
Triangulation of mode S sources
AFTN
Aeronautical fixed telecommunications network
Each station has its own individual address
consisting of 8 letters
The AFTN permits transmission of the following:
PERMITTED TRANSMISSION MATERIAL
Permitted Signs:
Alphabet
Numbers
Colon :
Semi-colon ;
Decimal Point .
Apostrophe ’
Oblique /
Plus +
Question Mark ?
Brackets ()
Comma ,
Double Hyphen =
AFTN Messages shall not contain the abbreviations:
SOH, STX, ETX, ZCZC, NNNN.
AFTN message priorities:
1- SS (distress and traffic)
2- DD or FF (urgency) (Flight safety messages)
3- GG or KK (Met messages) (regularity messages) (Aeronautical administrative Message)
Who assigns AFTN priority?
The person who signs off the message
When would a GG message be an FF message?
When the require immediate action
GG message
Met messages
regularity messages
Aeronautical administrative Message
NOTAMS and SNOWTAMS
FF messages
anything regarding movement and control
KK messages
Reservation messages
General Aircraft Operating Agency Messages
What is the reliability of OLDI?
99.86%
OLDI benefits
Automation of routine actions
Reduced controller workload
Better situational awareness
Indirect improvement of ATS system safety features.
Other AFTN networks-
OFTS
SITA
IACM
INDRA AIRSPACE CAPACITY MANAGER
EXCDS
EXTENTED COMPUTOR DISPLAY SYSTEM
SWIM
SYSTEM WIDE INFORMATION MANAGMENT
Advantages of PSR over SSR?
Self contained
Independent operation
Non reliant
Permanent echoes
Weather info
Advantages of SSR over PSR?
Lower transmitter power
No ground weather or clutter
Simple display of Ident
Vertical info
Emergency squawks
Independent of echoing area
Disadvantages of PSR over SSR?
No level info
No ident
Weather clutter
Range depends on specific factors
No emergency indication
ADS-C contracts
Periodic
Demand
Event
Types of ACARS messages
ATC
AOC
AAC