RADAR Flashcards
What is the order of the electromagnetic spectrum?
Radio, microwaves, Infrared, Visible, UltraViolet, X-Rays, Gamma Rays.
What are the specs of our radar?
Synthetic Aperture
Doppler beam sharpening & pulse doppelar
Phase modulated
What dictates resolution in range and azimuth?
Range-Pulse width
Azimuth-beamwidth
Describe antenna gain?
Ability to focus energy in a given direction
Describe mono pulse tracking?
Like sequential lobing except single lobe and 4 receivers detect errors
Describe sequential lobing
Antenna beams switch between multiple locations alternately. Angular error can be indicated. Sequential lobing gives the position of the target with high accuracy.
What are the 3 types of radar tracking?
Conical
Sequential lobing
Monopulse
What dictates antenna size?
Frequency
How many modes can the radar operate at a time
2 in alternate sweeps (ONLY THE NAV CAN SELECT THIS)
What are the six possible radar modes
- Weather
- Map (either doppelar bean sharpening DBS or monopulse ground mapping MGM, or real beam ground map RBGM)
- Beacon (ground beacon GBCN, or Air beacon ABCN)
- Skin paint
- Precision measurement
- ## Windshear mode
What does RTP stand for & where is it located. How is it cooled?
Receiver, transmitter, processor.
Located just forward of the LOX container in nose wheel well
Cooled by ducted cooled air from built in fans
Where is the radar antenna and what 3 things does it consist of?
In the radome housing
- RF amplifier
- Processer
- Drive motors
Radar power requirements?
28V DC & 115V AC From ESS AC BUS
What is the radar system called
AN/APN-241
How do you select two separate modes?
- Beacon mode can be overlayed onto WX, MAP or SP by selecting one of the 3, then Beacon.
OR - The operator can select PREC mode once Map (DBS or MGM is selected)
However the Nav will only be able to select one mode if the pilot control panel is in charge
When is the pilot in control of the radar?
How to pass back & foward the control
- If the pilot station is powered up >15 secs before the Nav station
- PLT button on Nav control panel
Increments for rocker controlled parameters?
- 0.2deg for angles
- 1dB for gain
- 1 (of 16) grey shade for video brightness
What buttons are not functional on the LEP?
SKE, FP and ORIG
How is a failure of the Low voltage power supply (LVPS) indicated?
If no radar display is observed within 11 seconds after the guarded power ON button is pressed, and both Nav & Pilot “ON” lights are out.
When selecting MAP button, what modes does it switch between, and when will it auto-select each one
- DBS Selected when map falls within coverage - MGM when INU DEGR, INU ALIGN or ATT DEGR is detected - RBGM When STAB LOST is detected
What displays when turbulence is indicated
Flashing bright green (1/2 sec on, 1/2 sec off)
What beam is WX mode performed in
Pencil beam
Describe in basic terms the windshear mode & what scan pattern?
coherent pulse doppelar designed to detect the presence of low level microburst windshear in the T/O & landing environments. Uses a two bar scan pattern
Describe the WS mode two bar scan pattern
The lower bar is a function of altitude & and scans just above the terrain to measure low level horizontal winds
The upper scan bar looks up approx 5deg.
WS mode then combines data from the two bars to make an estimation of vertical windshear.
Display format for WS mode
- 10nm range (WS processed for 5nm)
- Only HDG up display available
- Displays normal weather
- When WS is detected, superimposed icons appear (Red & black striped)
How big is a hazard area of WS
Generally defined as at least 900m