Definition
A ground-based Doppler radar system installed at or near major airports to detect hazardous wind conditions in the terminal area, particularly low-altitude wind shear and microbursts on or near the approach and departure paths. It measures the speed and direction of precipitation and other airborne particles, allowing controllers to issue real-time wind shear and microburst alerts to pilots.
Plain English
A special radar at busy airports that watches for sudden, dangerous wind changes near the runway and warns pilots before they take off or land.
Context Anchor
Pilots may encounter Terminal Doppler Weather Radar information through air traffic control weather alerts, especially during arrivals and departures at larger airports.
Derivation
Doppler refers to the Doppler effect, the change in frequency of a wave when its source moves toward or away from the observer. The radar uses this effect to measure how fast raindrops and particles are moving toward or away from the antenna, which reveals the wind. 'Terminal' here means the airspace immediately around an airport, not an end point.
Why Pilots Care
Provides advance warning of wind shear that can produce sudden airspeed loss on approach or departure, directly affecting go/no-go and escape maneuver decisions.
Grounding Statement
Picture a radar near a busy airport watching rain and wind movement around the approach and departure paths.
Intuition Check
“Terminal” does not mean the airport passenger building here. It means the area around an airport where takeoffs, landings, and close-in air traffic are occurring.
Example Sentence 1
Tower issued a wind shear alert from the Terminal Doppler Weather Radar, and the crew elected to hold short until conditions improved.
Example Sentence 2
During summer operations the Terminal Doppler Weather Radar frequently issues microburst alerts on the ATIS at major hubs.