ATC equipment radar principles Flashcards
(23 cards)
What does RADAR stand for?
Radio detection and ranging
What is PSR?
Primary surveillance radar, returns horizontal position.
What is SSR?
Secondary surveillance radar, uses a 4 digit squark code to identify a/c and sometimes shows extras like level info depending on mode.
What will weather affect more, long wavelength or short wavelength?
Short
How fast does an SMR spin?
45-60 RPM
What are the 3 SSR modes?
A - Identity
C - Level information
S - Extra information
What is MTI?
Moving target indicator, uses the Doppler effect to tell if something is moving and removes clutter.
What is one problem with MTI?
If an a/c flys at a tangent to the radar it causes tangential fade and the radar may remove it as clutter.
What is an advantage of PSR?
A/c do not need any equipment on board for it to work.
What are 5 disadvantages of PSR?
- Requires a strong signal and correct signal therefore suffers from signal attenuation.
- Shows clutter.
- Provides limited information.
- Distance given is slant range.
What numbers can be used for squark codes?
As it uses 3-bit binary only numbers 0-7 can be used.
How many mode A squark codes are there?
4096
What are the 2 types of SSR codes?
- Discreet codes (Assigned)
- Conspicuity code
What are 5 advantages of SSR?
- Less transmitter power required for similar range.
- No ground or weather clutter.
- Provides aircraft identification.
- Level information if mode C or S.
- Provides use of conspicuity codes.
What are 4 disadvantages of SSR?
- A/c requires a transponder.
- No weather or clutter displayed.
- Label garbling.
- Possible antenna shadowing will mean a/c is not displayed.
What are 5 advantages of mode S?
- More accurate.
- Provides controller / pilot information via uplink and downlink capabilities.
- Allows the a/c to fly in class A and C airspace.
- Almost 17 million aircraft addresses.
- More accurate info for (STCA and TCAS 2)
What is shown by elementary mode S?
- Automatic Identification
- More accurate level info (25ft)
- Flight status (On ground or in flight)
What is shown by enhanced mode S?
- Magnetic heading
- Speed (IAS and Mach number)
- Roll angle
- Rate of turn
- Climb rate
- Ground speed
- Selected flight level
What is ADS?
Automatic dependent surveillance is a surveillance technique where a/c automatically report Nav data via data link including a/c identification.
What are the two ADS versions?
ADS-B and ADS-C
What is ADS-B
Broadcast, Broadcasts data out to everyone.
What is ADS-C
Contract, only ANSPs with a contract receive the data. Only used in low traffic areas.
What is MLAT?
Multilateration system, a group of equipment configured to provide position derived from the SSR.
