1. ADS-B Technology Overview
Marc Ramsey
PASCO Safety Seminar
Oakland, California
November 4, 2006

2. Topics What is ADS-B? How Does ADS-B Work? Why Ground Stations?
Broadcast Services
Current Continental US ADS-B Coverage
Expanded Coverage: 2008 to 2010?
Universal Access Transceivers
Will ADS-B Replace Transponders?
Why Should We Care?
What Can We Do?

3. What is ADS-B? Automatic Dependent Surveillance Broadcast
Periodically transmits information with no pilot or operator input
Dependent
Position and velocity data derived from Global Positioning System (GPS)
Surveillance
Determines position of aircraft, vehicles, or ground obstructions
Broadcast
Transmitted data available to anyone with appropriate receiving equipment

4. How Does ADS-B Work? ADS-B transmitter periodically transmit:
Unique identifier
3D Position and velocity vector from GPS
Altitude from pressure sensor and/or GPS
ADS-B receiver receives:
Data from nearby ADS-B transmitters
Traffic and weather data from ground stations
ADS-B transceiver transmits and receives
Two types of ADS-B devices
Mode S/ES (Extended Squitter) at 1090 MHz
UAT (Universal Access Transceiver) at 978 MHz
Intended for General Aviation use

5. Why Ground Stations?
Receive position/velocity data from ADS-B (both UAT and S/ES) equipped aircraft
Pass received data to ATC system
Obtain traffic data from ATC system for other ADS-B and transponder equipped aircraft
Broadcast composite traffic data
Broadcast weather and airspace data
Each station has a range of 100 to 150 miles

6. Who Can See Who?
GS Ground Station
SSR Secondary Surveillance Radar

7. Broadcast Services: TIS-B
Traffic Information Service
Provides real-time position reports
ADS-B equipped aircraft
Mode B/C equipped aircraft from secondary surveillance radar data

8. Broadcast Services: FIS-B
Flight Information Service
National Weather Service products
NEXRAD
Special use airspace
Temporary flight restrictions (TFRs)

9. Current Continental US ADS-B Coverage

10. Expanded Coverage: 2008 to 2010?

11. Universal Access Transceiver
Transmits current state vector (3D position/velocity) once per second
Receives TIS-B and FIS-B
Low transmit power requirements
Low power (limited to 18,000 feet) 7 to 18 watts
Medium power (no alt. Restriction) 16 to 40 watts
Short transmit duty cycle (0.03%)
Garmin GDL 90
Only UAT currently certified
$8000 without display
$16,500 with color display

12. Will ADS-B Replace Transponders?
Short answer: eventually…
Most air transport aircraft equipped by 2020
Most other aircraft equipped by 2030
Advantages
Precise position data on all aircraft in ATC system
UAT transceivers will eventually be smaller, lighter, and use less current than Mode C
ADS-B ground stations less expensive and cover wider area than primary/secondary radar systems
What’s holding it up?
Lack of integration with TCAS
Lack of ground stations

13. Why Should We Care? Potential benefits Potential Issues
Allow gliders, paragliders, hangliders, etc. to be fully integrated into future ATC system
Ultimately much lower power requirements than existing Mode C or S transponders
Integrated collision avoidance
Real-time glider tracking for contests, etc.
Potential Issues
Short term lack of suitable units
Competition
UAT equipped gliders can be tracked by competitors
Weather data available to UAT equipped competitors

14. What Can We Do?
Push for short term installation of ground station in Reno area
Propose pilot program involving subsidized installation of UATs in Reno area gliders
Ask for waiver allowing occasional use of low power UATs in wave windows
Can we interest someone in developing low cost, low power UAT using PDA as display?
Other ideas?

15. Winch Launch Update Recent trip to UK BGA transition training
Lasham
Bicester
Cambridge
Remember to get your medical form
BGA transition training
2 to 4 normal launches
2 high failures
2 medium failures
2 low failures
Any interest?
Contact me