Automatic Dependent Surveillance And Multilateration Flashcards
What does ADS B stand for?
Automatic Dependent Surveillance-Broadcast
What does ADS B do?
Broadcasts horizontal/vertical position, velocity and other information
What can ADS-B be used by?
Aircraft and vehicles
Can ADS-B be received by ground facilities?
Yes
ADS-B enables a passive system to monitor uniquely, identify and track all targets.
True or False?
True
What is ADS-B reliant upon?
Users providing accurate information all of the time
What frequency is the extended squitter for ADS-B?
1090MHz
What does ASS-B make use of?
SSR frequency and Mode S
What are the 4 requirements for aircraft regarding ADS-B?
1) GPS Navigation Capability
2) Mode S Transponder
3) Avionics capable of providing correct data
4) Correct connections between the 3 above
How much Does ADS- B cost compared to radar?
0.1%
Can ADS-B ground stations can be built in remote areas.
True or False?
True.
How are their communications typically linked?
Satellite and microwave
ADS-B has two types of messages what are they?
Primary and on event
What information is in the primary Type of message in ADS-B?
Position (Surface and Airborne)
- Airborne Velocity
- Aircraft Identification
What 3 details are in the “on event” Message in ADS-B?
Trajectory
Status
Test
How many messages per second are produced by ADS-B?
6.2 messages per second
ADS-B permits high update rates. How many messages per second for Velocity?
2 mps
ADS-B permits high update rates. How many messages per second for On event messages?
2 mps
ADS-B permits high update rates. How many messages per second for flight identity?
0.2 mps (5 seconds)
What is the maximum accuracy category for ADS-B?
7.5m
What is the minimum accuracy category for ADS-B?
> 20nm
How does ADS-B remove aerial shadowing?
ADS-B can place antennas and GAP fill
What does ADS-C stand for?
Automatic Dependent Surveillance Contract
What is different about ADS-C?
This relies upon specific contracts being established between the ground system and the aircraft’s avionics via a data link.
“C” means that the ground system provides the aircraft with a list of reports to send and specifies when they are required to be sent.
True or False?
True.
What are the 3 types of ADS-C contracts?
Periodic
Demand
Event
What does MLAT use for its data?
Several antennae on the ground receive broadcasts from aircraft and vehicle mode S transponders
What does TDOA stand for?
Time difference of Arrival
How does MLAT calculate the position of the aircraft?
Uses a process called Time Difference of Arrival (TDOA)
What does MLAT process?
The data encoded in the Mode S and ADS transmitters
What are the benefits of MLAT?
Small and cheap antennae easy to install and cheaper to maintain compared to SMR
Provides rapid update and more accurate positions the SMR
What does WAM stand for?
Wide Area MLAT
Can MLAT be used alongside Radar and ADS?
Yes
What are the limitations of MLAT?
Similar to SSR and ADS only detects aircraft or vehicles with Mode S transponders
