System Operation

Distributed Observation, Centralized Processing

AWAS uses a multi-point wind field monitoring architecture. Multiple wind speed and direction sensors can be installed around the airport according to runway configuration, terrain conditions, and windshear risk, continuously collecting wind data from different areas.

Each monitoring station transmits wind speed and direction data to a central processing system. The system compares wind vectors from different locations and analyzes convergence, divergence, and sudden changes in wind speed across the airport environment.

When significant wind speed gains or losses are detected within runway approach or departure areas, the system can automatically generate alerts and provide air traffic controllers with information on the affected runway area, location, and estimated wind change, helping them respond to potentially hazardous weather conditions in real time.

Windshear and Microburst Alerts

Wind Shear Alert
When the system detects a significant wind change along a flight path, it may generate a windshear alert. In some aviation windshear alert systems, a wind speed loss of approximately 15 to 29 knots may trigger a Wind Shear Alert.

Microburst Alert
When the system detects more severe wind speed loss and strong outflow characteristics, it may generate a microburst alert. In some systems, a wind speed loss of 30 knots or more is used as an important threshold for a Microburst Alert.

Actual alert thresholds, algorithms, and display methods should be configured according to the system manufacturer, airport layout, and applicable aviation regulations.

System Advantages

Continuous Ground-Level Wind Monitoring
AWAS directly measures actual wind speed and direction around the airport and does not rely on precipitation returns. This allows the system to continuously provide wind information for runway, approach, and departure areas.

Low-Latency Real-Time Data
By continuously updating data from multiple anemometers, the system can quickly identify changes in wind speed and direction between different areas and provide timely information to air traffic control personnel.

Cost-Effective Windshear Monitoring
Compared with large-scale weather radar systems, a ground-based anemometer network generally has a simpler system architecture and lower installation and maintenance costs, making it an important component of airport low-level windshear monitoring.

System Limitations

Detection Coverage Depends on Sensor Placement
AWAS relies primarily on fixed ground-based sensors, so its detection capability is affected by the number, location, and coverage of monitoring stations. Windshear occurring outside the sensor network or at higher altitudes may not be detected in advance.

Complex Terrain May Affect Wind Data
Buildings, mountainous terrain, sea breezes, and local turbulence around an airport may create complex wind patterns. Sensor placement and detection algorithms therefore need to be engineered according to the specific conditions of each airport.

Limitations of a Single Detection Method
Ground-based anemometers mainly measure near-surface horizontal wind conditions. Their ability to provide advance warning of windshear at higher altitudes or rapidly developing severe microbursts may therefore be limited.

Multi-Source Windshear Detection and Data Fusion

Modern large airports generally do not rely on a single type of sensing equipment. Instead, multiple meteorological detection systems are integrated to improve the detection of low-level windshear and microbursts.

AWAS / LLWAS
Ground-based anemometer networks monitor actual wind speed and direction changes around runways and airport operating areas.

TDWR – Terminal Doppler Weather Radar
Doppler weather radar is used to detect thunderstorms, gust fronts, windshear, and microbursts, particularly under precipitation conditions.

Doppler LIDAR
Doppler LIDAR measures wind by detecting aerosols and particles in the atmosphere, making it especially useful for windshear detection in clear-air and non-precipitation conditions.

Other Meteorological Sensors
Depending on airport requirements, the system may also integrate automatic weather stations, wind profilers, weather buoys, and other meteorological observation equipment to create a more comprehensive aviation weather monitoring network.

Benefits of System Integration

By integrating data from multiple meteorological sensing technologies, airports can improve the coverage, reliability, and early-warning capability of low-level windshear and microburst detection while providing air traffic controllers and flight operations personnel with more complete real-time weather information.