SAMRA (Radio Aids/Navigation) Flashcards
PSR transponder requirement and view limitations:
No transponder needed
- Used for weather
- Picks up birds
- 80NM range
How is SSR used?
Uses time interval between interrogation and reply from aircraft transponder
pressure altitude, longer range
Transponder up to 250NM range
What is TSR?
Terminal service radar
What is PAR?
Precision approach radar
What is mode A transponder?
Base, no altitude!
What is ADSE?
Airport surface detection equipment
What is mode C transponder?
Position with altitude encoding (pressure altitude in aircraft transponder)
What is mode S transponder?
A and C with TCAS abilities! S, TCAS
Two aircraft equipped with mode S and TCAS II can communicate to each other for RAs using the mode S transponder
Can send ADS-B messages
2 types of weather detection equipment:
- Weather radar unit
- Lightning detection unit (storm scope)
Advantages to storm scope:
- Not susceptible to the same attenuation as radar
- Tends to cost less
3. Not dependent on line-of-sight, able to detect lightning behind mountains - Possible to detect turbulence within clouds of little or no precipitation
- Stormscopes can provide an arc or 360 degree view of electrical activity of aircraft
Weather radar works on the basis of:
Primary surveillance radar
Uses a beam of energy sent out and reflects back towards antenna, shows target/echo
Reflects water! Top-down view, density/intensity of water
What type of precipitation is most reflective on a weather radar?
- Rain
- Wet snow
- Wet hail
designed for LIQUID precipitation
Least reflective: dry hail, ice crystals, dry snow
What type of precipitation is least reflective?
- Dry hail
- Ice crystals
- Snow
The amount of energy returned to the antenna on a weather radar is dependent on:
- Type of precipitation
- Concentration
- Water droplet size (returns the greatest energy)
Exam question will be which one of the three is the MOST reflective? WATER DROPLET SIZE
Where would you scan a thunderstorm to find its severity?
Lower half of storm!
Attenuation is based on what factors:
- Distance
- Further you are the more energy is lost use to beam dispersal and storm is understated - Heavy precipitation
- Radar energy is absorbed and cannot detect a cell behind the area of heavy precipitation
- This is where the tilt function needs to be used!
What does the gain function do?
Changes colours on map.
Up gain = show green as a yellow, yellow as red, etc.
Down gain = show magenta as red, red as yellow, etc.
You can use the gain (turn down) to find specific cells if your screen is showing entirely red.
does NOT change sensitivity!!!
Using a weather radar what would you look for to decipher a severe thunderstorm echo/target?
- Irregular shape
- Shape is rapidly changing
Indicates hail, severe turbulence, icing, wind shear, tornadoes
Ground based weather radar can detect what types of precipitation:
- Rain
- Snow
- Drizzle
- Hail
does NOT detect volcanic ash!
What types of imagery are available for ground based weather radar?
Precipitation rate for SNOW (INCLUDING HAIL)
or
Precipitation rate for RAIN (INCLUDING VIRGA)
Echo tops
Ground based weather radar modes:
- National
- Regional
- Single
Source of aviation weather in Canada:
NAV Canada
Compiles all weather in the world, they just collect it all to display
When are GFAs issued?
Approximately 30min before the beginning of the coverage period
for ALL 6 GFAs!!!! It’ll show the issuance time for each one and all 6 read the same time!
GFA:
Time observed:
1800Z, 0000Z, 0600Z, 1200Z (remember the order!)
Time issued:
Approximately 30min before the beginning of the coverage period
Altitude concerned:
AT or below 24,000ft, can include convective weather above FL240
Remarks:
Graphically depicts forecast weather over a period of time, do NOT forget about the IFR outlook and its addition to its total validity time
- Each GFA is valid for 12hrs