1. Avionics Systems Day 5
Section 2

2. RADAR
 RAdio Detection And Ranging
 Ground based
 ATC
 Aircraft based
 Weather radar
 Radio altimeter

3. RADAR
 Radar operates on the “Pulse Echo
principle”
 A short pulse of radio energy is transmitted
 Receiver waits for reflected energy

4. ATC Radar
 Aircraft separation under IFR conditions
 UHF
 Controllers watch aircraft on screens and
give pilots instructions on where to fly

6. Aircraft Radar
 Severe weather avoidance
 Thunderstorms
 Allows pilots to continue flying while
avoiding storm cells

8. Aircraft Radar
 Clouds are invisible to radar, however
ice, rain, & hail will reflect the energy
 Size & intensity of moisture & radar type
will effect the image displayed

10. Aircraft Radar
 Be careful when operating radar on
ground
 Microwaves can be dangerous
 Point into sky
 Outside

11. C-BAND 5400 MHz
 Used primarily by airline operations
 Can see through clouds better
 Less reflective off of small cells to reveal
larger cells behind

12. X-BAND 9333 MHz
 Used by general aviation
 Greater resolution
 Will reflect off of smaller cells with greater
resolution but will not see behind cells

13. Stormscope
 A lower cost storm detection system
 Uses an AM directional receiver that
detects lightning discharge
 NOT RADAR

14. Stormscope
 Uses a loop antenna & a microprocessor
to determine the direction to a lightning
strike / storm cell
 Displays lightning strike data on a screen

16. Radar Altimeter
 A.K.A. Radio Altimeter or simply RAD ALT
 A single target radar system used to
indicate aircraft AGL (Above Ground
Level) altitude
 4300 MHz
 Measures the time it takes for a radio
pulse to go to the ground and return

18. Radar Altimeter
 Antenna is located on belly of aircraft
 Usually measures no higher than 5000 ft
 Usually used during landing

19. GPWS
 Ground Proximity Warning System
 Warns pilot of excessively low altitude
 “PULL UP!” “PULL UP!”

20. GPWS
 Computer monitors several different
systems
 Radar Altimeter
 Air data computer
 Landing gear
 Flaps
 Glideslope
 Primary component is the computer

21. GPWS
 Warnings are activated during flight
 Terrain avoidance (gear & flaps up)
 During landing
 Excessive rate of descent
 Below glideslope
 Below minimums
 Enhanced GPWS systems incorporate a
worldwide terrain database & GPS
inputs