Introduction to Aerospace Electronics

8/14/2019 Introduction to Aerospace Electronics

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Introduction to

Aerospace Electronics

Introduction to

Aerospace ElectronicsAE 1350

AE 1350



Avi ation Electr onics

Avionics



Avionics Development History• Wireless Communication (1920s-1930s)• Navigation (1930s-1940s)

• Surveillance Systems (1940s)• Autopilots and Missile Guidance (1940s)

• Stability Augmentation (1950s)• Precision Navigation (1950s)• “Modern” Air Traffic Control (1950s-1960s)• Remote Sensing (1960s)



Radar in WWII

Chain Home radar



Flying blind, Doolittle in 1929





α

North

X

30 revolutionsper second

The signal at x is proportional to 1 + a cos( ω t - α )The signal at X is effectively AM

modulated by 30 Hz



VHF Omnidirectional Range (VOR)



World VOR

-90

-60

-30

0

30

60

90

-180 -150 -120 -90 -60 -30 0 30 60 90 120 150 180



USA VOR

20

35

50

-125 -110 -95 -80 -65





Distance Measuring Equipment (DME)

T x R x

Transponder

1025 - 1150 MHz(126 channels)

962 - 1024 MHz or 1151 - 1213 MHz

Reply

Interrogation



Instrument Landing System (ILS)

• Localizer for Lateral Information• Glideslope for Altitude Information• Marker Beacons to Check Progress• Sometimes DME Also• Sometimes NDB on Approach Course



Localizer Antenna

This one is for aircraft approaching from the other direction!

*Airborne Antenna Often Shared With VOR



Glideslope Antenna

Be sure to look for these structures next time you fly!



6000 Flights in the Air...



Automated Radar Terminal System (ARTS)



Raytheon ASR-11

• Digital Airport Surveillance Radar (DASR) latest version of the terminal area surveillance radars

– Bottom: primary radar surveillance• Max range 60 miles• Operates in the range of 2700 to 2900 MHz• The transmitter generates a peak effective power of 25 kW and an

average power of 2.1 kW – Top: interrogating transponders

• Aircraft data for barometric altitude,identification code

• 1030 to 1090 MHz, transmitting power ranges from 160 to 1500 watts.



Northrop Grumman ARSR-4

• Air Route Surveillance Radar (ARSR) 4• Long-range, three-dimensional, rotating phased array, primary radar

system with coverage of 250 nmi for en route operation

• 1215-1400 MHz• There are 43 operational systems deployed around the periphery of the

continental U.S., as well as in Guam, Hawaii, and Guantanamo Bay, Cuba• Expensive to maintain, they

were to have beendecommissioned untilSept 11, 2001



‘Command Center’, Herndon VA



Problems With Current System• Agreed Upon:

– Very Safe

– Works Well Until Reaches Saturation – We’re At Saturation

• In USA, Busiest Airports Are Saturated

• In Europe, En-Route Airspace Is Saturated• What to do?

– Distributed System Model

– Swiss-Train Model



Early Uses of Stability Augmentation

B-47

YB-49



Importance for Non-piloted Vehicles

V-2

RQ-1 Predator

Ariane 5



New Configurations Made PossibleB-2

A320



Super-augmented Aircraft

X-29

F-16



Satellite Communications

radioelectronics.com



Remote Sensing (60s)



Inertial Navigation Systems• A set of gyroscopes maintain a

stable platform, regardless of whatever motions the missile goesthrough

• Within that platform are sensorsthat measure acceleration

• This information is sent to a digitalcomputer, which translates thatdata into information about thevehicle current location andvelocity

• Prior to launch, the computer is

given information about the pointof launch, the gravitational fieldover which it will fly

• Solution can be updated in flight

(inertial aiding)LGM-30 Minuteman III

Apollo CM



More Avionics Development History• Autonomous Vehicles (Spacecraft, Aircraft) (1970s)• Precision Guidance Systems (1970s)

• Flight Management Systems (1970s)• System and Vehicle Health Management; Controls

and Displays (1980s)• Digital Engine Control (1980s)• Cockpit Alerting Systems (1980s)

• Sat Comm and Sat Nav (1980s)• Stealth (1980s)

(M ) A t Ai ft d



(More) Autonomous Aircraft andSpacecraft (70s)

Voyager-1

Teledyne Ryan AQM-34L



Precision Guidance

S t d V hi l H lth



System and Vehicle HealthManagement

• Commercial Airliners go from a crew of 5 in 1950s – Pilot

– Copilot – Navigator – Radio Operator

– Flight Engineering• …to a crew of 2 in the 1980s

– Pilot – Copilot – (Dispatcher)



Gemini Spacecraft



Space Shuttle



Space Shuttle (After Upgrade)



Cockpit Complexity on Spacecraft

2300997Shuttle1374740Apollo35427Gemini14313Mercury

ControlDisplay

Elements

WorkStations

PanelsProgram



Airplane as a Computer Peripheral

A380





Advanced Displays: Egocentric Perspective



Head Up Displays (HUD)





Night Vision Goggles

AN/AVS-6 Aviator’s Night Vision Imaging System(ANVIS)



Enhanced Vision Systems



Synthetic Vision Systems



Human Error

• Human error, at some level, has caused every aviationaccident

• Pilot error is implicated (at some level) in 70%+ fatalaccidents – Becoming a larger percentage as mechanical systems improve

• What is the correct point of view? – “Humans are wonderfully adaptable agents, but they are slow to

react and are dangerously prone to error…”

• According to this, why have a human operator at all? – “What we call human error is really the negative consequences of

normal human behavior that is not accounted for in design.”



Human Error & Implications for Design

• Through

– Knowledge of Possible Errors – Good Design Principles

• Developers Can – Prevent Errors – Make the System More Flexible in the Face of Errors

Traffic Alert and Collision Avoidance



Traffic Alert and Collision AvoidanceSystem (TCAS-II)

Enhanced Ground Proximity Warning



Enhanced Ground Proximity WarningSystem (EGPWS)



Global Positioning System (GPS)• NAVSTAR GPS (Navigation Signal Timing and

Ranging Global Positioning System)

• Number of Satellites 24 Active, 4 Spare• Geometry 6 planes, 4 satellites each

– MEO - 20,200 km (10,900 nmi) circular

– 55° inclination



Control Segment



Stealth

F-117

Documents

Introduction to Aerospace Electronics