Introduction To Aerospace Electronics

Introduction to Aerospace Electronics AE AE 1350 1350

Aviation Electronics 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

VOR Transmitter

The signal at x is proportional to 1

+ a cos(ωt - α)

The signal at X is effectively AM modulated by 30 Hz North X

30 revolutions per second

α

VHF Omnidirectional Range (VOR)

World VOR 90

60

30

0 -180

-150

-120

-90

-60

-30

0

-30

-60

-90

30

60

90

120

150

180

USA VOR

50

35

20 -125

-110

-95

-80

-65

Distance Measuring Equipment (DME)

1025 - 1150 MHz (126 channels)

Tx

Interrogation Reply

962 - 1024 MHz or 1151 - 1213 MHz Transponder

Rx

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 *Airborne Antenna Often Shared With VOR

This one is for aircraft approaching from the other direction!

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 been decommissioned until Sept 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 Possible B-2

A320

Super-augmented Aircraft F-16

X-29

Satellite Communications

radioelectronics.com

Remote Sensing (60s)

Inertial Navigation Systems •

• • Apollo CM •

• LGM-30 Minuteman III

A set of gyroscopes maintain a stable platform, regardless of whatever motions the missile goes through Within that platform are sensors that measure acceleration This information is sent to a digital computer, which translates that data into information about the vehicle current location and velocity Prior to launch, the computer is given information about the point of launch, the gravitational field over which it will fly Solution can be updated in flight (inertial aiding)

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)

(More) Autonomous Aircraft and Spacecraft (70s)

Voyager-1

Teledyne Ryan AQM-34L

Precision Guidance

System and Vehicle Health Management • 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 Program

Mercury Gemini Apollo Shuttle

Panels

Work Stations

3 7 40 97

1 2 7 9

Control Display Elements 143 354 1374 2300

Airplane as a Computer Peripheral

A380

Cessna 182

Advanced Displays: Egocentric Perspective

Head Up Displays (HUD)

Head/Helmet Mounted Display

AH-64 Integrated Helmet and Display Sighting System (IHADSS)

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 aviation accident • Pilot error is implicated (at some level) in 70%+ fatal accidents – 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 System (TCAS-II)

Enhanced Ground Proximity Warning System (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