ATC Basics: ATC Surveillance Sources

What is a radio detection device which provides information on range, azimuth, and/or elevation of objects?

Radar

What is a radar system in which a minute portion of a radio pulse is transmitted from a site reflected by an object & received back at the site for processing and displaying on a screen (affected by anything with mass)?

Primary radar

What is the reflected energy sent out by primary radar called?

Echo/target

Does primary radar require aircraft equipment?

No

What are the 4 components for primary radar?

1. Transmitter

2. Antenna

3. Receiver

4. Display

What does the transmitter do in primary radar?

Generates a pulse of radio energy

What does the antenna do in primary radar?

Focuses & broadcasts radio energy and then collects the reflected return

What is the blind zone?

The area directly above an antenna

What does the receiver do in primary radar?

Amplifies & converts the reflected energy into video

What does the radar display do in primary radar?

Depicts the position & movement of objects that reflect radio energy

What is a radar system in which the object to be detected is fitted with cooperative equipment?

Secondary radar

Where is the transponder located on an aircraft?

Belly

What are the 5 components of secondary radar?

1. Interrogator

2. Antenna

3. Transponder

4. Decoder

5. Radar display

What does the interrogator do in secondary radar?

Generates radio signals

What does the antenna do in secondary radar?

Broadcasts radio signals

What does the transponder do in secondary radar?

Receives the interrogator’s signals & automatically replies

How does the transponder send signals?

Received by antenna, sent to interrogator, relayed to decoder

What does the decoder do in secondary radar?

Processes the transponder replies & sends them to radar display

What does the radar display do in secondary radar?

Depicts an electronic presentation of radar-derived information

What are the advantages of secondary radar? (3 items)

1. Less vulnerable to blind spots

2. Provides a longer range than primary radar

3. Responses are not degraded by weather/ground clutter

What are the disadvantages of secondary radar? (3 items)

1. Only displays aircraft with transponders

2. Does not provide weather information

3. Return is affected by aircraft orientation

What does the kite-like signal mean on the radar?

Airspace boundary

What does ==\== mean on a radar display?

Airport

What does ^ mean on a radar display?

Obstruction

What does a diagonal + mean on radar display?

Airway intersection

What does ° mean in a radar display?

NAVAID

What is a surveillance system in which an aircraft to be detected is fitted with a data link transmitter & the aircraft periodically broadcasts its GPS and other information?

ADS-B (Automatic Dependent Surveillance-Broadcast)

How often are signals broadcasted, and do they require pilot action in ADS-B?

Every second, no

What does ADSB require for it to function?

Aircraft to be equipped with proper equipment

What technology does ADSB use to provide aircraft position and altitude?

GNSS (global navigation satellite system)

How are signals broadcasted to ATC in ADSB?

Automatically through ground stations

What are the main components ADSB relies on?

1. ADSB transponder

2. Constellation of GPS satellites

3. Network of ground stations

4. Broadcast communications link

What is a basic level of aircraft equipment that only broadcasts its own location & doesn’t receive input from others?

ADSB Out

What is equipment that allows aircraft to view a multitude of valuable information, including others’ location, weather info, NOTAMs, etc?

ADSB In