ATM Communications Navigation and Surveillance SYST 460 560 Fall 2003 G.L. Donohue.

ATM Communications Navigation ATM Communications Navigation and Surveillanceand Surveillance

SYST 460 560

Fall 2003

G.L. Donohue

Evolution of CNS/ATMEvolution of CNS/ATM

1922 ATC begins

1930 Control Tower

1935, an airline consortium opened the first Airway Traffic

Control Station

Airway Centers

1940s Impact of radar

1960s & 70s

ADS-B GPS

Page 11-15 Katon, Fried

Radio FrequenciesRadio Frequencies

Name Abbreviation

Frequency

Frequency Wave length

Very low VLF 3 to 30 kHz 100 to 10km

Low LF 30 to 300 kHz 10 to 1km

Medium MF 300 to 3000 kHz 1km to 100 m

High HF 3 to 30 MHz 100 to 10m

Very high VHF 30 to 300 MHz 10 to 1cm

Ultrahigh UHF 300 to 3000 MHz 1m to 10cm

Super high SHF 3 to 30 GHz 10 to 1cm

Extremely high EHF 30 to 300 GHz 10 to 1mm

Line-of-Sight WavesLine-of-Sight Waves

VHF and UHF have about 70 nmi. Range at 6,000 ft. altitude

Line-of-sight range

WeatherWeather

• Instrument meteorological conditions (IMC) are weather conditions in which visibility is restricted, typically less than 3 miles

• Acft operating in IMC are supposed to fly under IFR

Visibility Categories (by ICAO) Visibility Categories (by ICAO) (1)(1)

• Category I– Decision height not lower than 200 ft; visibility not

less than 2600 ft, or Runway Visual Range (RVR) not less than 1800 ft with appropriate runway lighting.

– The pilot must have visual reference to the runway at the 200ft DH above the runway or abort the landing.

– Acft require ILS and marker-beacon receiver beyond other requirements for flights under IFR.

– Category I approaches are performed routinely by pilots with instrument ratings


• Category II – DH not lower than 100 ft & RVR not less than 1200 ft

(350m)– The pilot must see the runway above the DH or abort

the landing– Additional equipment that acft must carry include

dual ILS receivers, either a radar altimeter or an inner-marker receiver to measure the DH, an autopilot coupler or dual flight directors, two pilots, rain-removal equipment (wipers or chemicals), and missed-approach attitude guidance. An auto-throttle system also may be required


• Category III subdivided into– IIIA. DH lower than 100 ft and RVR not less than 700

ft (200m)-sometimes called see to land: it requires a fail-passive autopilot or a head-up display

– IIIB. DH low than 50 ft & RVR not less than 150 ft (50m)-sometimes called see to taxi; it requires a fail-operational autopilot & an automatic rollout to taxing speed

– IIIC. Zero visibility. No DH or RVR limits. It has not been approved anywhere in the world

Decision HeightDecision Height

• Acfts are certified for decision heights, as are crews

• When a crew lands an acft at an airport, the highest of the three DHs applies.

• An abort at the DH is based on visibility

• Alert height is the altitude below which landing may continue in case of equipment failure – Typical Alert height is 100 ft

Integrated Avionics Subsystems Integrated Avionics Subsystems (1)(1)

1. Navigation

2. Communication

– intercom among the crew members & one or more external two-way voice & data links

3. Flight control

– Stability augmentation & autopilot

– The former points the airframe & controls its oscillations

– The latter provides such functions as attitude-hold, heading-hold, altitude hold

4. Engine control

– The electronic control of engine thrust(throttle management)


5. Flight management– Stores the coordinates of en-route waypoints and

calculates the steering signals to fly toward them

6. Subsystem monitoring & control– Displays faults in all subsystems and recommends

actions to be taken

7. Collision-avoidance– Predicts impending collision with other acft or the

ground & recommends an avoidance maneuver


8. Weather detection– Observes weather ahead of the acft so that the

route of flight can be alerted to avoid thunderstorms & areas of high wind shears

– Sensors are usually radar and laser

9. Emergency locator transmitter(ELT)– Is triggered automatically on high-g impact or

manually – Emit distinctive tones on 121.5, 243, and 406 MHz

The Vehicle The Vehicle

Avionics Placement on multi-purpose transport

Architecture Architecture (1)(1)

• Displays;

– Present information from avionics to the pilot

– Information consists of vertical and horizontal navigation data, flight-control data (e.g. speed and angle of attack), and communication data (radio frequencies)


• Flight controls;

– The means of inputting information from the pilot to the avionics

– Traditionally consists of rudder pedals and a control-column or stick

– Switches are mounted on the control column, stick, throttle, and hand-controllers


• Computation;

– The method of processing sensor data

– Two extreme organizations exist:

1. Centralized; Data from all sensors are collected in a bank of central computer in which software from several subsystems are intermingled

2. Decentralized; Each traditional subsystem retains its integrity


• Data buses– Copper or fiber-optics paths among sensors,

computers, actuators, displays, and controls

• Safety partitioning– Commercial acft sometimes divide the avionics to;

1. Highly redundant safety-critical flight-control system

2. Dually redundant ,mission-critical flight-management system

3. Non-redundant maintenance system– Military acrft sometimes partition their avionics for

reason other than safety


• Environment

– Avionics equipment are subject to;

• acft-generated electricity-power transient, whose effects are reduced by filtering and batteries,

• externally generated disturbances from radio transmitters, lightening, and high-intensity radiated fields

– The effect of external disturbances are reduced by

• shielding metal wires and by using fiberoptic data buses

• add a Faraday shielding to meal skin of the acft


• Standards– Navaid signals in space are standardized by ICAO– Interfaces among airborne subsystems, within the

acft, are standardized by Aeronautical Radio INC. (ARINC), Annapolis Maryland, a nonprofit organization owned by member airlines

– Other Standards are set by:• Radio Technical Commissions for Aeronautics,

Washington DC• European Organization for Civil Aviation

Equipment (EUROCAE)• etc.

Human NavigatorHuman Navigator

• Large acft often had (before 1970) a third crew member, flight engineer:– To operate engines and acft subsystems e.g. air

conditioning and hydraulics)– Use celestial fixes for positioning

• Production of cockpits with inertial, doppler, and radio equipments facilitated the automatically stations selection, position/waypoint steering calculations and eliminated the number of cockpit crew to two or one.

Communications is the Glue for Communications is the Glue for ATM-CNSATM-CNS

Context for Communication ArchitectureContext for Communication ArchitectureContext for Communication ArchitectureContext for Communication Architecture

Operational Concepts

Traffic Mgmt Synchronization ATC AdvisoryFlt Plan Service

Process user preferences

TechConcepts

Services

FunctionalCapabilities

EnablingCommunicationLinks

• FIS• TIS• CPDLC• CPC• DSSDL• AOCDL• ADS-B• AUTOMET• APAXS

FP Processing

• VHF-AM• ACARS• VDL-2• VDL-3• VDL-4• VDL-B• SATCOM• MODE-S• UAT• HFDL

Message TypesMessage Types Message Types

Communications Architecture

FUNCTIONAL ARCHITECTURE

Air-Ground Comm Functional ArchitectureAir-Ground Comm Functional ArchitectureAir-Ground Comm Functional ArchitectureAir-Ground Comm Functional Architecture

AIRCRAFT

OTHERAUTHORIZED

USERSNWIS•INTERNATIONAL•MILITARY•FBO’S

•TV, RADIO•INTERNET

AUTOMET

CPC

CPDLC

DSSDL

ADS-B

POSITION/INTENT

VOICE

MESSAGING

NEGOTIATIONAIRCRAFT

AOCCOMM

•WEATHER•NAS STATUS

AIRLINESOPERATIONS

CENTER

AIRTRAFFIC

CONTROL

OPERATIONS, MAINTENANCE

ADS-B

AIRBORNE WEATHER OBSERVATION

FIS TIS APAXS

CommercialService Provider

NATIONALWEATHERSERVICE

Benefits Driven ConceptBenefits Driven ConceptBenefits Driven ConceptBenefits Driven Concept

Tactical Control

Strategic CDM

AutomatedNegotiation

Bro

ad

cast

2-w

ay

InfoBase

DSS-based

Human-based

Air Traffic Control

Aircraft

Range of User Equipage

• DSSDL

• CPC• CPDLC• AOCDL

• CPC• CPDLC

TechnicalConcepts

Dynamic Data

Static Data • FIS

• TIS• ADS-B• FIS• AUTOMET

Aeronautical Operational Control

AOCDL

Functional AnalysisFunctional AnalysisFunctional AnalysisFunctional Analysis

• 9 Technical Concepts

• Defined Message categories and message types for each Technical Concept

• Concept Description

• Concept Diagram

Architecture Alternatives SummaryArchitecture Alternatives SummaryArchitecture Alternatives SummaryArchitecture Alternatives Summary

Operational ConceptTechnical Concept

VHF-AM VDL-2/ ATN

VDL-3/ ATN

VDL-4/ ATN

VDL-B Mode-S UAT SATCOM-Broadcast

SATCOM-2way

Aircraft continuously receive Flight Information to enable common situational awareness

FIS

Aircraft continuously receive Traffic Information to enable common situational awareness

TIS

Controller - Pilot Communication CPC

Controller - Pilot messaging supports efficient Clearances, Flight Plan Modifications, and Advisories (including Hazardous Weather Alerts)

CPDLC

Aircraft exchange performance / preference data with ATC to optimize decision support

DSSDL

Aircraft continously broadcast their position and intent to enable optimum maneuvering

ADS-B

Pilot - AOC data exchange supports efficient air carrier/air transport operations and maintenance

AOCDL

Aircraft report airborne weather to improve weather nowcasting/forecasting

AUTOMET

Passengers enjoy in-flight television, radio, telephone, and internet service

APAXS

Acceptable Alternative NAS Architecture AATT CSA Recommendation

Operational Concept - Tech ConceptOperational Concept - Tech ConceptOperational Concept - Tech ConceptOperational Concept - Tech Concept

Message CategoriesMessage CategoriesMessage CategoriesMessage Categories

Concept Description - Flight Information Concept Description - Flight Information ServiceService

Concept Description - Flight Information Concept Description - Flight Information ServiceService

Aircraft continually receive dynamic Flight Information to enable common situational awareness• Weather Information• NAS Status• NAS Traffic Flow Status

Note: We assume that static data will be loaded on aircraft via portable storage media prior to

flight.

Msg ID (M#)

Message Category Definition/Comment Source (1)

M15 Convection Includes data regarding cloud tops, freezing level, lightning activity, projected decay, water content, etc. 33

M17 Departure ATIS AutomaticTerminal Information Service (Airport Domain)80

M18 Destination Field Conditions Combination of text, icons, and graphics potentially describing NOTAM information, RCR readings, ramp snow conditions, de-icing necessity, arrival rates, etc. 33

M20 En Route Strategic General Imagery Backup for synthesized weather products or for direct imagery requirement. Examples include satellite photos, lightning strike data, hand drawn surface analysis. 33

M21 FIS Planning - ATIS AutomaticTerminal Information Service (Terminal Domain)80

M22 FIS Planning Services Includes real-time weather advisories and warnings80

M26 General Hazard A general hazard product would likely include weather hazards in addition to other known hazards (traffic, terrain..) 33

M27 Icing (Terminal Tactical) May not be practical, difficult to implement. Would depend on automatic reports from in flight aircraft to a central ground location for constant plotting, updating and reporting.

33M28 Icing/ Flight Conditions (En Route Far

Term, Near Term Strategic, Tactical)IMC and icing are included in this product aimed at GA.

33M29 Low Level Wind Shear (Terminal Tactical) This product may identify dangerous shearing winds caused by microbursts, frontal passage, etc.

Generated from ground-based sensors, fused with NEXRAD or TDWR data to create a near-ground level view. 33

M35 Radar Mosaic Real-time broadcasts of NEXRAD or TDWR-type RADAR pictures in the terminal area.33

M37 Surface Conditions (En Route Far Term Strategic)

This product will project surface conditions to enhance situational awareness and support contingency planning 33

M39 Turbulence (En Route Far Term and Near Term Strategic, En route Tactical)

Strategic Turbulence information will become one of the most important future products. A true tactical product may not be feasible but future product may combine current sensed condition with next available nowcast.

33M40 Winds/Temperature (En Route Far Term

and Near Term Strategic)This product contains information on Enroute winds and temperatures

33Note: (1) Source 33 is the Data Communications Requirements, Technology and Solutions for Aviation Weather

Information Systems (Phase I Report), Lockheed Martin Aeronautical Systems 1999

Source 80 is RTCA DO 237, Aeronautical Spectrum Planning, 1997

FIS Message SetFIS Message SetFIS Message SetFIS Message Set

Flight Information Service - FIS Flight Information Service - FIS

SATCOM

CommI/F

SATCOMRCVR

VDLRCVR

MFDSOASIS

• NOTAM

FISPROC

WARP

AircraftAir / Ground Comm

Ground Systems

NAS / SUASTATUS

NEXRAD NWSWx

Vendor(s)ADAS

PortableStorageMedia

WxSensor(s)

AAIS

CommNetwork

CommNet-work

ATIS CSP

NWIS INTEGRATEDNETWORK

VDL Comm

Network

Ground-Based Pilot PC

AC

NETWORK

UAT Comm Network

UATXCVR

UAT

ADS-BGND RCVR

SecondaryPrimary

ATCFacility

UAT

CommNetwork

CommI/F


Ground Systems

Automation

SATCOMRCVR

ADS-BXCVR

AAIS

ADS-BProcessor

UAT Comm Network

UATXCVR

MFDS

•CDTI

LAN

AC

NETWORK

Traffic Information Services TISTraffic Information Services TISTraffic Information Services TISTraffic Information Services TIS

VDL-B VDL-BXCVR

VDL-B Comm

Network

CSP

SATCOM

ARTCC

TRACONVDL-3 XCVR

MFDS

AAIS


Ground Systems

Automation

Automation CommI/F

Automation CommI/F

Automation CommI/F

TOWER

FSS

VDL CommNetwork

CommI/F

LAN

LAN

LAN

LAN

AC

NETWORK

Controller / Pilot Data Link Communications Controller / Pilot Data Link Communications CPDLCCPDLC

Controller / Pilot Data Link Communications Controller / Pilot Data Link Communications CPDLCCPDLC


Ground Systems

CPC Controller/Pilot Voice CommunicationCPC Controller/Pilot Voice CommunicationCPC Controller/Pilot Voice CommunicationCPC Controller/Pilot Voice Communication

ATCVoice

VoiceSwitch

VHFVoiceRadio

Pilot Voice

FTI Comm

Network

VDLRadio

VoiceData

ExistingA/G Radio

NEXCOMRADIO

CommHead

FTI CommNetwork

CommI/F

ARTCC

TRACONVDL-3 XCVR

AAIS

FMS


Ground Systems

Automation

Automation CommI/F

Automation CommI/F

TOWER

LAN

LAN

LAN

AC

NETWORK

Decision Support System Data Link DSSDLDecision Support System Data Link DSSDLDecision Support System Data Link DSSDLDecision Support System Data Link DSSDL

AOC

VDL-2XCVR

MFDS

FMS

AAIS

AircraftAir / Ground CommGround Systems

Automation

CSPVDL-2 Comm

Network

CommI/F

LAN

AC

NETWORK

Aeronautical Operational Control Data Link Aeronautical Operational Control Data Link AOCDLAOCDL

Aeronautical Operational Control Data Link Aeronautical Operational Control Data Link AOCDLAOCDL

AOCDL Message SetAOCDL Message SetAOCDL Message SetAOCDL Message Set

Msg ID (M#)

Message Type

M8 Airline Maintenance Support: Electronic Database Updating

M9 Airline Maintenance Support: In-Flight Emergency Support

M10 Airline Maintenance Support: Non-Routine Maintenance/ Information Reporting

M11 Airline Maintenance Support: On-Board Trouble Shooting (non-routine)

M12 Airline Maintenance Support: Maintenance/ Information Reporting

M19 Diagnostic Data

M23 Flight Data Recorder

M25 Gate Assignment

M30 Out/ Off/ On/ In

M33 Position Reports

ADS-BGND RCVR

SecondaryPrimary

ATCFacility

CommNetwork

CommI/F


Ground Systems

Automation

GPSRCVR

AAIS

MFDS

ADS-BXCVR ADS-B

FMS

GPS

LAN

AC

NETWORK

Automatic Dependent SurveillanceAutomatic Dependent Surveillance - Broadcast ADS-B - Broadcast ADS-B

Automatic Dependent SurveillanceAutomatic Dependent Surveillance - Broadcast ADS-B - Broadcast ADS-B

Automated Meteorological Transmission - AUTOMET

Automated Meteorological Transmission - AUTOMET

SATCOM

CommI/F

SATCOMXCVR

VDLXCVR

UATXCVR

NWSPROC

FSL


Ground Systems

NASAWx

Sensor(s)

CommNet-work

AOC CSP

VDL Comm

Network

AC

NETWORK

FMS

UAT Comm

Network

Data Link SummaryData Link Summary

Data Link SingleChannel

Data Rate

Capacity forAeronautical

Communications

ChannelsAvailableto Aircraft

# AircraftSharingChannel

(ExpectedMaximum)

Comments

kbps Channels Channels AircraftHFDL 1.8 2 1 50 Intended for OceanicACARS 2.4 10 1 25 ACARS should be in decline as

users transition to VDL Mode 2VDL Mode 2 31.5 4+ 1 150 System can expand indefinitely as

user demand growsVDL Mode 3 31.5* ~300 1 60 Assumes NEXCOM will deploy to

all phases of flightVDL Mode 4 19.2 1-2 1 500 Intended for surveillanceVDL – B 31.5 2 1 Broadcast Intended for FISMode-S 1000** 1 1 500 Intended for surveillanceUAT 1000 1 1 500 Intended for surveillance/FISSATCOM - - - - Assumes satellites past service lifeFutureSATCOM

384 15 1 ~200 Planned future satellite

Future KaSatellite

2,000 ~50 ~50 ~200 Estimated capability - assumescapacity split for satellite beams

FourthGenerationSatellite

>100,000 >100 >100 Unknown Based on frequency license filings

* Channel split between voice and data.** The Mode-S data link is limited to a secondary, non-interference basis with the surveillance function and has a capacity of 300 bps per

aircraft in track per sensor (RTCA/DO-237).

Top Down Architecture -Top Down Architecture -

Primary 2-wayCPC / CPDLC / DSSDL

Secondary 2-wayAOC / AUTOMET

FIS / TIS / APAXS

Data TransmitADS-B

SATCOM

VDL-2

VDL-3

UATVDL-4

Mode-S

CSPNetwork

FTINetwork

CSPNetwork

CSPInterface

Ground Link Aircraft

ADS-BSite

FTINetwork

NEXCOMSite

FTINetwork

2007 Architecture - UAT Data2007 Architecture - UAT Data

Secondary 2-wayCPDLC / DSSDLAOC / AUTOMET

FIS - Regional

Data TransmitADS-B

UAT

VDL-2

VHF-AMNEXCOMSite

CSPNetwork

ADS-BSite

FTINetwork

CSPNetwork

CSPInterface

Ground Link Aircraft

VDL-B

FIS / TIS

FTINetwork

FTINetwork

Navigation RcvrWAAS / LAAS / VOR

Surveillance XpndrSeparation / TCAS

Mode-A/C/S

WAAS / LAASAugmentation Network

RadarSite

VOR Site VOR

FTINetwork

Navigation / Surveillance Functions

CPC - Voice

SATCOMCSP Network APAXS

Communication Architecture Schedule - FISCommunication Architecture Schedule - FIS Communication Architecture Schedule - FISCommunication Architecture Schedule - FIS

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Research

Standards

Systems

Certification

Research

Standards

Systems(data links)

Research

Standards

Systems

Gro

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VDL-B

SATCOM

SATCOM Ant / Rcvr Integrated Demo

FIS-BSATCOM

V- SATCOM

Link Simulation

FIS-B

FIS-B

FIS-B SATCOM

FIS-B SATCOM

NAS Wide Info System

NWIS Data

AOC / CDM Network

WARP Wx Network

NWIS

System Operational time span

FIS Data Compression

FTI

UAT

UAT

Communication Architecture Schedule - TISCommunication Architecture Schedule - TISCommunication Architecture Schedule - TISCommunication Architecture Schedule - TIS

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Research

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Research

Standards

Systems

Gro

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VDL-B

SATCOM

SATCOM Ant / Rcvr Integrated Demo

VDL-B SATCOM

V- SATCOM

Link Simulation


NWIS Data

AOC / CDM Network

NWIS


TIS Data Compression

TIS-B SATCOM

TIS-B SATCOM

TIS-B SATCOM

FTI

UAT

UAT

Communication Architecture Schedule - CPDLCCommunication Architecture Schedule - CPDLCCommunication Architecture Schedule - CPDLCCommunication Architecture Schedule - CPDLC00 10 11 12 13 14 1501 02 03 04 05 06 07 0908

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Systems

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Research

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VDL-2VDL-3

VDL-2 MMR

CPDLC

CPDLC VDL-2


NWIS Data

FTINWIS


DLAPDLAP -R

VDL-3 MMR

CPDLC VDL-3

Voice Synthesis Demo

Voice Synthesis

CPDLC

Additional MSG for Hz Wx

Prioritization of HzWx on VDL-2

Communication Architecture Schedule - AOCDLCommunication Architecture Schedule - AOCDLCommunication Architecture Schedule - AOCDLCommunication Architecture Schedule - AOCDL


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VDL-2 Mod 1

VDL-2 MMR

CPDLC

CPDLC VDL-2

FTINWIS

DLAP

VDL-2 MMR

DSSDL

DSSDL VDL-2

DLAP - M1

DSSDLIntegrated Demo

DSSDL Integrated Demo

DSSDL Integrated Demo

VDL-2

VDL-2 MMR

AOCDL VDL-2

AUTOMET

AUTOMET

AOCDL

CPDLCDSSDL

Communication Architecture Schedule - ADS-BCommunication Architecture Schedule - ADS-BCommunication Architecture Schedule - ADS-BCommunication Architecture Schedule - ADS-B

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Mode-S / UAT / VDL-4


NWIS Data

NWIS


UATMode-S

FTI

ADS-B

ADS-B Mode-S / UAT

SF-21, CAPSTONE

ADS-B Link Evaluation

Technology Link Decision

VDL-4

Communication Architecture Schedule - Cross-cuttingCommunication Architecture Schedule - Cross-cuttingCommunication Architecture Schedule - Cross-cuttingCommunication Architecture Schedule - Cross-cutting

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Air

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VDL-BVDL-2

VDL-3

SATCOM

C, Ku, S SATCOM

V- SATCOM


UATMode-S

VHF-AM

Systems

Gro

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AOC / CDM Network

WARP Wx Network NWIS

FTI

NWIS Data

Information Security

Multifunction Display

Symbology

Cross Cutting Technology GapsCross Cutting Technology GapsCross Cutting Technology GapsCross Cutting Technology Gaps

ArchitectureRequirement

Cross Cutting TechnologyIssues

System orComponent

Segment

2007/2015 Ground Air Space2015 NAS-Wide Information System New System

RequiredCom. Interface to Distributed NAS

Wide Database (standard dataset, access protocol, user

verification)

New System x x

2007 Information Security Improved DatalinkRequired

Authentication New System x xData Validation Improved System x x

Protection from Interference Improved System x x x

NavigationNavigation

Navigation: Geometry of The EarthNavigation: Geometry of The Earth

• For navigational purposes, the earth’s surface can be represented by an ellipsoid of rotation around the Earth’s spin axis

• The size & shape of the best-fitting ellipsoid is chosen to match the sea-level equal-potential surface.

Geometry of The EarthGeometry of The Earth

Fig 2.2

Median section of the

earth, showing the reference ellipsoid &

gravity field

Coordinate FramesCoordinate Frames

• The position, velocity and attitude of the aircraft must be expressed in a coordinate frame: WGS-84

Navigation coordinate

frame

Navigation PhasesNavigation Phases

Picture courtesy of MITRE Corporation

Aircraft System HierarchyAircraft System Hierarchy

Time to go

Range, bearing to displays, FMS

Steering signals to autopilot

Star line of sight

Dead-reckoning

computations

Positioning computatio

ns

Celestial equations

•Positioning sensors

•Radio(VOR, DME, Loran, Omega)

•Satellite (GPS)

•Radar

•Inertial air data

•Doppler

Most probable position

computation

Course

computations

Heading attitude

Way points

Position data

•Position

•Velocity

•Attitude

Position

Velocity

To map display

To weapon computers

To cockpit display pointing sensorAttitud

e

Block diagram of an aircraft navigation

system

Terminal Area NavigationTerminal Area Navigation

1. Departure: begins from maneuvering out the runway, ends when acft leaves the terminal-control area

2. Approach: acft enters the terminal area, ends when it intercepts the landing aid at an approach fix

• Standard Instrument Departure (SIDs) & Standard Terminal Approach Route (STARs)

• Vertical navigation Barometric sensors

• Heading vectors Assigned by traffic controller

En Route NavigationEn Route Navigation

• Leads from the origin to the destination and alternate destinations

• Airways are defined by navaids over the land and by lat/long over water fixes

• The width of airways and their lateral separation depends on the quality of the navigation system

• From 1990s use of GPS has allowed precise navigation

• In the US en-route navigation error must be less than 2.8 nm over land & 12 nm over ocean

Approach NavigationApproach Navigation

• Begins at acquisition of the landing aid until the airport is in sight or the acrft is on the runway, depending on the capabilities of the landing aid

• Decision height (DH): altitude above the runway at which the approach must be aborted if the runway is not in sight

– The better the landing aids, the lower the the DH

– DHs are published for each runway at each airport

– An acrft executing a non precision approach must abort if the runway is not visible at the minimum descent altitude (typically=700 ft above the runway)

Landing NavigationLanding Navigation

• Begins at the DH ends when the acrf exits the runway

• Navigation may be visual or navigational set’s may be coupled to a autopilot

• A radio altimeter measures the height of the main landing gear above the runway for guiding the flare

• The rollout is guided by the landing aid (e.g. the ILS localizer)

Missed ApproachMissed Approach

• Is initiated at the pilot’s option or at the traffic controller’s request, typically because of poor visibility. And alignment with the runway

• The flight path and altitude profile are published

• Consists of a climb to a predetermined holding fix at which the acrf awaits further instructions

• Terminal area navaids are used

VHF Omnidirectional VHF Omnidirectional Range(VORRange(VOR))

• Receiver characteristics– The airborne equipment comprises a horizontally polarized receiving antenna &

a receiver. This receiver detects the 30 Hz amplitude modulation produced by the rotating pattern & compares it with the 30 Hz frequency-modulated

reference. – Fig 4.16

Doppler VORDoppler VOR

• Doppler VOR applies the principles of wide antenna aperture to the reduction of site error

• The solution used in US by FAA involves a 44-ft diameter circle of 52 Alford loops, together with a single Alfrod loop in the center

• Reference phaseThe central Alford loop radiates an omni-directional continuous wave that is amplitude modulated at 30 Hz

• The circle of 52 Alford loops is fed by a capacitive commutator so as to simulate the rotation of a single antenna at a radius of 22ft

• Rotation is at 30rps, & a carrier frequency 9960 Hz higher than that in the central antenna is fed to the commutator

• With 44-ft diameter & a rotation speed of 30 rps, the peripheral speed is on the order of 1400 meters per second, or 480 wavelengths per second at VOR radio frequencies

Distance-Measuring Equipment Distance-Measuring Equipment (DME) (DME) (1)(1)

• DME is a internationally standard pulse-ranging system for acft, operating in the 960 to 1215 MHz band. In the US in 1996, there were over 4600 sets in use by scheduled airlines and about 90,000 sets by GA

DME Operation

Distance-Measuring Equipment Distance-Measuring Equipment (DME) (DME) (2)(2)

• The acft interrogator transmits pulses on one of 126 frequencies, spaced 1 MHz apart, in the 1025 to 1150 MHz band. Paired pulses are used in order to reduce interference from other pulse systems. The ground beacon(transponder) receives these pulses & after a 50 sec fixed delay, retransmits them back to the acft. The airborne automatically compares the elapsed time between transmission and reception, subtracts out the fixed 50 sec delay, & displays the result on a meter calibrated in nautical miles.

Hyperbolic SystemsHyperbolic Systems

• Named after the hyperbolic lines of position (LOP) that they produce rather than the circles– Loran-C

– Omega

– Decca

– Chayka

Measure the time-difference between the signal from two or more transmitting station

Measure the phase-difference between the signal transmitted from

pairs of stations

Long-Range Navigation(Loran)Long-Range Navigation(Loran)

• A hyperbolic radio-navigation system beginning before outbreak of WW II

1. Uses ground waves at low frequencies, thereby securing an operating range of over 1000 mi, independent of line of sight

2. Uses pulse technique to avoid sky-wave contamination

3. A hyperbolic systemit is not subject to the site errors of point-source systems

4. Uses a form of cycle (phase) measurements to improve precision

• All modern systems are of the Loran-C variety

Long-Range Navigation (Loran-C)Long-Range Navigation (Loran-C)

• Is a low-frequency radio-navigation aid operating in the radio spectrum of 90 to 110 kHz

• Consists of at least three transmitting stations in groups forming chains

• Using a Loran-C receiver, a user gets location information by measuring the very small difference in arrival times of the pulses for each Master -Secondary pair

• Each Master-Secondary pair measurement is a time difference. One time difference is a set of points that are, mathematically, a hyperbola. Therefore, position is the intersection of two hyperbolas. Knowing the exact location of the transmitters and the pulse spacing, it is possible to convert Loran time difference information into latitude and longitude

Loran-C Loran-C (2)(2)

Signal shapeSignal shape

Position Position determinationdetermination

Loran-C Loran-C (2)(2)

NAVSTAR Global Positioning NAVSTAR Global Positioning SystemSystem

• GPS was conceived as a U.S. Department of Defense (DoD) multi-service program in 1973, bearing some resemblance to & consisting of the best elements of two predecessor development programs:

– The U.S. Navy’s TIMATION program

– The U.S. Air Force’s program

• GPS is a passive, survivable, continuous, space-based system that provides any suitably equipped user with highly accurate three-dimensional position, velocity, and time information anywhere on or near the earth

Principles of GPS & System Principles of GPS & System OperationOperation

• GPS is basically a ranging system, although precise Doppler measurements are also available

• To provide accurate ranging measurements, which are time-of-arrival measurements, very accurate timing is required in the satellite. (t<3 nsec)

– GPS satellite contain redundant atomic frequency standards

• To provide continues 3D navigation solutions to dynamic users, a sufficient number of satellite are required to provide geometrically spaced simultaneous measurements.

• To provide those geometrically spaced simultaneous measurements on a worldwide continues basis, relatively high-altitude satellite orbits are required

GPS Satellite System ConfigurationGPS Satellite System Configuration

• Consists of three segments– Space segment

– Control segment

– User segment

GPS System ConfigurationGPS System Configuration

General System CharacteristicsGeneral System Characteristics

• The GPS satellites are in approximately 12 hour orbits(11 hours, 57 minutes, and 57.27 seconds) at an altitude of approximately 11,000 nmi

• The total number of satellite in the constellation has changed over the years ~24

• Each satellite transmits signals at two frequencies at L-Band to permit ionosphere refraction corrections by properly equipped users

General System CharacteristicsGeneral System Characteristics

• The GPS satellites are in approximately 12 hour orbits(11 hours, 57 minutes, and 57.27 seconds) at an altitude of approximately 11,000 nmi

• The total number of satellite in the constellation has changed over the years ~24

• Each satellite transmits signals at two frequencies at L-Band to permit ionosphere refraction corrections by properly equipped users

The GPS segmentsThe GPS segments

Segments Input Function Product

Space •Satellite commands

•Navigation messages

•Provide atomic time scale

•Generate PRN RF signals

•Store & forward navigation message

•PRN RF signals

•Navigation message

•Telemetry

Control •PRN RF signals

•Telemetry

•Universal coordinated

•Time(UTC)

•Estimate time & ephemeris

•Predict time & ephemeris

•Manage space assets

•Navigation message

•Satellite commands

User •PRN RF signals

•Navigation messages

•Solve navigation equations •Position, velocity, & time

GPS Space SegmentGPS Space Segment

• The space segment is comprised of the satellite constellation made up of multiple satellites. The satellite provides the basic navigation frame of reference and transmit the radio signals from which the user can collect measurements required for his navigation solution

• Knowledge of the satellites’ position and time history (ephemeris and time) is also required for the user’s solutions.

• The satellite also transmit that information via data modulation of the signals

•CDMA @ 1.2 to 1.5 GHz

•LB and “P” “C”

•Very accurate atomic clocks ~< nanosecond

GPS Control SegmentGPS Control Segment

• Consists of three major elements– Monitor stations that track the satellites’ transmitted

signals & collect measurements similar to those that the user collect for their navigation

– A master control station that uses these measurements to determine & predict the satellites’ ephemeris & time history and subsequently to upload parameters that the satellite modulate on the transmitted signals

– Ground station antennas that perform the upload control of the satellite

User SegmentUser Segment

• Is comprised of the receiving equipment and processors that perform the navigation solution

• These equipments come in a variety of forms and functions, depending upon the navigation application

Basics of Satellite Radio Basics of Satellite Radio Navigation Navigation (1)(1)

• Different types of user equipments solve a basic set of equations for their solutions, using the ranging and/or range rate (or change in range) measurements as input to a least-squares, or a Kalman filter algorithm.

• Fig 5.2

Ranging satellite radio-navigation

solution


• The measurements are not range & range rate (or change in range), but quantities described as pseudorange & pseudorange rate (or change in pseudorange). This is because they consisit of errors, dominated by timing errors, that are part of the solution. For example, if only ranging type measurements are made, the actual measurement is of the form

is the measured peseudorange from satellite i

is the geometric range to that satellite, is the clock error in satellite i, is the user’s clock error, c is the speed of light and is the sum of various correctable or uncorrectable measurements error

iPRusiii tctcRPR iPR

iR sit utiPR


• Neglecting for the moment the clock and other measurement errors, the range to satellite i is given as

are the earth-centered, earth fixed (ECEF) position components of the satellite at the time of transmission and are the ECEF user position components at that time

222usiusiusii ZZYYXXR

sisisi andZYX ,

uuu andZYX ,

Atmospheric Effects on Satellite Atmospheric Effects on Satellite CommunicationCommunication

• Ionosphere:– Shell of electrons and electrically charged atoms & molecules

that surrounds the earth– Stretching from 50km to more than 1000km– Result of ultraviolet radiation from sun – Free electrons affect the propagation of radio waves– At frequency below about 30 MHz acts like a mirror bending the

radio wave to the earth thereby allowing long distance communication

– At higher frequencies (satellite radio navigation) radio waves pass through the ionosphere

System AccuracySystem Accuracy

• GPS provides two positioning services, the Precise Positioning Service (PPS) & the Standard Positioning Service (SPS)

• The PPS can be denied to unauthorized users, but SPS is available free of charge to any user worldwide

• Users that are crypto capable are authorized to use crypto keys to always have access to the PPS. These users are normally military users, including NATO and other friendly countries. These keys allow the authorized user to acquire & track the encrypted precise (P) code on both frequencies & to correct for international degradation of the signal– WAAS < 3 m horizontal < 7.5 m vertical– GPS 15m

Automatic Landing Systems Automatic Landing Systems (1)(1)

• Air carrier acft that are authorized for precision-approach below category II must have automatic landing (auto-land) system.

1. Guidance & control requirements by FAA– For category II: the coupled autopilot or crew hold

the acft within the vertical error of +or- 12 ft at the 100ft height on a 3deg glide path

– For category III: the demonstrated touchdown dispersions should be limited to 1500ft longtudinally & -or+ 27ft laterally

Automatic Landing Systems Automatic Landing Systems (2)(2)

2. Flare Guidance During the final approach the glide-slope gain in

the auto-land system is reduced in a programmed fashion. Supplementary sensors must supply the vertical guidance below 100ft

3. Lateral Guidance Tracking of the localizer is aided by heading (or

integral-of-roll), roll, or roll-rate signals supplied to the autopilot and by rate & acceleration data from on-board inertial system

Instrument Landing System(ILS) Instrument Landing System(ILS) (1)(1)

• Is a collection of radio transmitting stations used to guide acft to a specific runway.

• In 1996 nearly 100 airports worldwide had at least one runway certified to Category III with ILS

• More than one ILS in high density airports

• About 1500 ILSs are in use at airports throughout the US

Instrument Landing System(ILS) Instrument Landing System(ILS) (2)(2)

• ILS typically includes:– The localizer antenna is centered on the runway beyond the stop end to

provide lateral guidance– The glide slope antenna, located beside the runway near the threshold

to provide vertical guidance– Marker beacons located at discrete positions along the approach path;

to alert pilots of their progress along the glide-path– Radiation monitors that, in case of ILS failure alarm the control tower,

may shut-down a Category I or II ILS, or switch a Category III ILS to backup transmitters

ILS Guidance Signals ILS Guidance Signals (1)(1)

• The localizer, glide slope, and marker beacons radiate continues wave, horizontally polarized, radio frequency, energy

• The frequency bands of operation are– Localizer, 40 channels from 108-112 MHz

– Glide slop, 40 channels from 329-335 MHz

– Marker beacons, all on a signal frequency of 75 MHz


• The localizer establishes a radiation pattern in space that provides a deviation signal in the acft when it is displaced laterally from the vertical plane containing the runway centerline

• The deviation signal drives the left-right needle of the pilot’s cross-pointer display & may be wired to the autopilot/flight-control system for coupled approaches

• The deviation signal is proportional to azimuth angle usually out to 5 deg or more either side of the center line


Sum & difference radiation

patterns for the course (CRS) &

clearance (CLR) signals of

a directional localizer array

The Localizer The Localizer (1)(1)

• The typical localizer is an array usually located 600 to 1000 ft beyond the stop end antenna of the runway

• The array axis is perpendicular to the runway center line

Log-periodic dipole

antenna used in many localizer arrays

The Localizer The Localizer (2)(2)

Category IIIB localizer

The Glide Slope The Glide Slope (1)(1)

• There are five different of glide-slope arrays in common use; three are image systems & two are not

• Image arrays depend on reflections from level ground in the direction of approaching acft to form the radiation pattern

– The three image systems are null-referenced system, with two antennas supported on a vertical mast 14 & 28 ft above the ground plane

– The sideband-reference system, with two antennas 7 and 22ft above the ground plane

– The capture-effect system, with 3 antennas 14, 28, and 42 ft above the ground plane

The Glide SlopeThe Glide Slope(2)(2)

Category IIIB capture-effect glideslope &

Tasker transmissometer


Glide-slope pattern near the runway. DDM counters are

symmetrical around the vertical, but signal strength

drops rapidly off

course


• The cable radiators of the end-fire array are installed on stands 40 in. high & are site alongside the runway near desired touchdown point

• Fig 13.10

• Fig 13.11

Standard end-fire glide-slope system layout

Front slotted-cable radiator of an end-fire

glide slope

ILS Marker Beacons ILS Marker Beacons (1)(1)

• Marker beacons provide pilot alerts along the approach path

• Each beacon radiates a fan-shaped vertical beam that is approximately +or- 40deg wide along the glide path by +-85deg wide perpendicular to the path – The outer marker(OM) is placed under the approach course near the

point of glide-path intercept & it is modulated with two 400 Hz Morse-code dashed per second

ILS Accuracy AllocationILS Accuracy Allocation

Standard lighting PatternStandard lighting Pattern

• Airports at which Category II landings are permitted must be equipped with the standard lighting pattern

Category III runway

configuration

The Mechanics of Landing The Mechanics of Landing (1)(1)

1. The approach

• Day & night landings are permitted under visual flight rules (VFR) when the ceiling exceeds 1000 ft & the horizontal visibility exceeds 3 mi, as juged by the airport control tower

• In deteriorated weather, operations must be conducted ubder Instrument Flight Rules (IFR)

– An IFR approach is procedure is either non-precision (lateral guidance only) or precision (both lateral & vertical guidance signals)• Category I, II, and III operations are precision-approach procedures


• An afct landing under IFR must transition from cruising flight to the final approach along the extended runway center line by using the standard approach procedures published for each airport

• Approach altitudes are measured barometrically, and the transition flight path is defined by initial & final approach fixes (IAF & FAF) using VOR, VOR/DME

• Radar vectors may be given to the crew by approach control


• From approximately 1500 ft above runway, a precision approach is guided by radio beams generated by ILS. Large acft maintain a speed of 100 to 150 knots during descent along the glide path beginning at the FAF (outer marker)

• The glide-path angle is set by obstacle-clearance and noise-abatement considerations with 3 deg as the international civil standard

• The sink rate is 6 to 16 ft/sec, depending on the acft’s speed & on headwinds


• The ICAO standard: glide path will cross the runway threshold at a height between 50 & 60 ft. Thus, the projected glide path intercepts the runway surface about 1000 ft from the threshold.

Wheel path for

instrument landing of a

jet acft

Wide Area Augmentation Wide Area Augmentation System(WAAS)System(WAAS)

• Developed by the FAA in parallel with European Geostationary Navigation Overlay Service (EGNOS) & Japan MTSAT Satellite-Based Augmentation System

• A safety-critical system consisting of a signal-in-space & a ground network to support en-route through precision approach air navigation

• The WAAS augments GPS with three services all phases of flight down to category I precision approach

1. A ground integrity broadcast that will meet the Required Navigation Performance (RNP)

2. Wide area differential GPS (WADGPS) corrections that will provide accuracy for GPS users so as to meet RNP accuracy requirements

3. A ranging function that will provide additional availability & reliability that will help satisfy the RNP availability requirements

WAAS Concept WAAS Concept (1)(1)


Inmarsat-3 four ocean-region deployment showing 5deg elevation

contours


• Uses geostationary satellite to broadcast the integrity & correction data to users for all of the GPS satellites visible to the WAAS network

• A slightly modified GPS avionics receiver can receive these broadcasts

• Since the codes will be synchronized to the WAAS network time, which is the reference time of the WADGPS corrections, the signals can also be used for ranging


• A sufficient number of GEOs provides enough augmentation to satisfy RNP availability & reliability requirements

• In the WAAS concept, a network of monitoring stations (wide area reference stations, WRSs) continuously track the GPS (&GEO) satellite & rely the tracking information to a central processing facility

• # Geo 2 minimum & 4 desired


• The central processing facility (wide area master station, WMS)m in turn, determines the health & WADGPS corrections for each signal in space & relays this information, via the broadcast messages, to the ground earth station (GESs) for uplink to the GEOs

• The WMS also determines & relays the GEO ephemeris & clock state messages to the GEOs

SurveillanceSurveillance

GPS+WAAS+DL = ADS-B

Automatic Dependent Surveillance - Automatic Dependent Surveillance - BroadcastBroadcast (ADS-B) (ADS-B)

• A technology designed to address both airspace and ground-based movement needs.

• Collaborative decision making is possible through ADS-B surveillance information available to both ATC and aircrews.

• ADS-B combined with predictable, repeatable flight paths allow for increased airspace efficiencies in high density terminal areas or when weather conditions preclude visual operations.

• Additionally, ADS-B allow for enhanced ground movement management (aircraft and vehicles) and improved airside safety

ADS-BADS-B

A/A Air to AirA/G Air to GroundAAC Airlines administrative communicationsAAIS Advanced Aircraft Information SystemAATT Advanced Air Transportation TechnologiesACARS aircraft communications addressing and reporting systemADAS AWOS data acquisition systemADS Automatic Dependent SurveillanceADS-B Automatic Dependent Surveillance - Broadcast AFSS automated flight service stationAIM Aeronautical Information ManualAIRMET Airman's Information ManualAM amplitude modulationAMS acquisition management systemAMS(R)S Aeronautical Mobile Satellite (Route) ServiceAMSRS Aeronautical Mobile Satellite (Route) ServiceAMSS Aeronautical Mobile Satellite SystemAOC airline operations centerARINC Aeronautical Radio Inc.ARTCC Air route traffic control centerASIST Aeronautics Safety Investment Strategy TeamASOS automated surface observing systemASR-9 airport surveillance radar- nineASR-WSP airport surveillance radar- weather system processorATC Air Traffic ControlATC DSS Air Traffic Control Decision Support SystemsATCSCC Air traffic Control System Command CenterATCT Air Traffic Control TowerATIS Automatic Terminal Information ServiceATM air traffic managementATN Aeronautical Telecommunication NetworkATS air traffic servicesATSP air traffic service providerAvSP Aviation Safety ProgramAWIN Aviation Weather Information ServicesAWIN Aviation Weather InformationAWOS automated weather observing systemBER bit error rateBER Bit Error RateCD compact diskCDM Collaborative Decision MakingCDMA Code Division Multple AccessCDTI Cockpit Display of Traffic Information

CNS Communications, Navigation and SurveillanceCONOPS concept of operationsCONUS Continental United StatesCOTS Commericial Off-The-ShelfCP conflict probeCPDLC Controller-Pilot Data Link Communications SystemCPU central processing unitCSA communications system architectureCSMA Carrier Sense Multiple AccessCTAS Center-TRACON Automation systemCWA Center Weather AdvisoryD8PSK Differential Eight-Level Phase Shift KeyingDA descent advisorDAG-TM Distributed Air/Ground Traffic ManagementDoD Department of DefenseDOT Department of TransportationDOTS dynamic ocean tracking systemDSR Display System ReplacementEMC Electromagnetic CapabilityEMI Electromagnetic InterferenceFAA Federal Aviation AdministrationFANS Future Air Navigation SystemFANS 1/A future air navigation systemFAR Federal Air RegulationsFAR Federal Aviation RegulationFBO Fixed Base OperatorFBWTG FAA bulk weather telecommunications gatewayFCC Federal Communications CommissionFDM flight data managementFDP flight data processorFEC Frame error checkFEDSIM Federal Systems Integration and Management CenterFFP1 Free Flight Phase 1FIS Flight Information ServiceFL flight levelFMS Flight Management SystemFOQA Flight Operational Quality AssuranceFP flight planFSS flight service stationFSS Fixed Satellite ServiceG/G Ground-to-GroundG/T Gain to System Noise Temperature RatioGA General Aviation

GEO Geostationary Earth OrbitGPS Global Positioning SystemHARS high altitude route systemHF high frequencyHF High FrequencyICAO International Civil Aviation OrganizationIF interfaceIFE In-Flight EntertainmentIFR Instrument flight rulesIFR Instrument Flight RulesIMC instrument meteorological conditionsIOC initial operating capabilityIP Internet ProtocolITWS Integrated terminal weather systemIWF Integrated Weather ForecastKBPS Kilobites Per SecondLAN Local Area NetworkLEO Low Earth OrbitLLWAS Low-level wind shear alert systemMBO Military Base OperationsMDCRS Meteorological Data Collection and Reporting SystemMEO Medium Earth OrbitMETAR meteorological aviation report MFD Multifunctional DisplayMOC Mission Operational ControlMOPS minimum operational performance standardsMSS Mobile Satellite ServiceMTBF Mean Time Between FailureN/A Not ApplicableNAS National Airspace SystemNAS RD NAS Requirements DocumentNASA National Aeronautics and Space AdministrationNATCA National Air Traffic Controllers AssociationNAWIS National Aeronautics and Space AdministrationNESDIS national environmental satellite, data, and information serviceNEXCOM Next Generation A/G Communications SystemNEXRAD next generation radarNLDN national lightning detection networkNOTAM Notice to AirmanNWS National Weather ServiceNWS/OSO National Weather Service/Office of Systems OperationsOASIS operational and supportability implementation systemOAT Office of Advanced TechnologyODAPS oceanic display and planning systemPFAST passive final approach spacing tool

PIREP Pilots ReportPIREPS pilot reportsPSK Phase Shift KeyingQAM Quadrature ModulationQoS Quality of ServiceRA resolution advisoryRCP Required Communications PerformanceRD requirements documentRF Radio FrequencyRTCA RTCA, IncorporatedRTO Research Task OrderRVR runway visual rangeSAIC Science Applications International CorporationSAR Search and RescueSARP Standards and Recommended PracticesSATCOM Satellite CommunicationsSIGMET Significant Meteorological InformationSOW Statement of WorkSPECI Special Weather ReportSSR Secondary Surveillance RadarSTC supplemental type certificateSUA Special Use Air SpaceTAF Terminal Aerodrome ForecastTBD to be determinedTDWR terminal Doppler weather radarTFM traffic flow managementTIS Traffic Information ServicesTM traffic managementTMS traffic management systemTRACON Terminal Radar Approach Control FacilityTRM Technical Reference ModelTWDL Two-Way Data LinkTWEB Transcribed Weather BroadcastTWIP terminal weather information for pilotsVDL very high frequency digital linkVFR visual flight rulesVHF very high frequencyVOR VHF-Omni Directional RangeWAAS Wide Area Augmentation SystemWAN Wide Area NetworkWARP weather and radar processorWJHTC William J. Hughes Technical CenterWMSCR weather message switching center replacementWx WeatherWxAP weather accident prevention

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ATM Communications Navigation and Surveillance SYST 460 560 Fall 2003 G.L. Donohue.

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