THE LOW-LEVEL WIND SHEAR ALERT SYSTEM (LLWSAS)
The results of the Low-Level Wind Shear Alert System (LLWSAS) field test and evaluation are reported. The system is a computer controlled anemometer mesonetwork used to detect near-surface wind discontinuities associated with strong thunderstorms and cold fronts -- those that are potentially hazardous to low-flying aircraft. The test and evaluation was conducted at seven major airports in the United States. This report discusses the principal meteorological events that will trigger alarms, the system hardware and software, and characteristics of the system that are unique to each airport. Heavy emphasis is placed on the proper siting of anemometry which was found to be the most important factor influencing high quality system performance. The siting criteria enumerated should serve as a model for future installations. Deviations from the model will severely impact system performance. The origin and justification for the vector difference threshold is discussed as well as LLWSAS by-products: wind gust determination and special displays for Terminal Radar Approach Control Facility (TRACON) rooms. (Author)
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Corporate Authors:
NATIONAL AVIATION FACILITIES EXPERIMENTAL CENTER
ATLANTIC CITY, NJ United StatesFederal Aviation Administration
800 Independence Avenue, SW
Washington, DC United States 20591 -
Authors:
- Goff, R C
- Publication Date: 1980-5
Media Info
- Pagination: 131 p.
Subject/Index Terms
- TRT Terms: Airports; Altitude; Anemometers; Data processing equipment; Gusts; Hazards; Information display systems; Location; Thunderstorms; Variables; Warning systems; Wind; Wind shear
- Uncontrolled Terms: Building sites; Low altitude
- Old TRIS Terms: Variations
- Subject Areas: Aviation; Design; Terminals and Facilities;
Filing Info
- Accession Number: 00318885
- Record Type: Publication
- Source Agency: National Technical Information Service
- Report/Paper Numbers: FAA-NA-80-1, FAA-RD-80-45
- Files: NTIS, USDOT
- Created Date: Oct 27 2002 12:00AM