Vaisala CT25K, Руководство пользователя

Страница: 76 / 86

LLWAS algorithm
The algorithm used in the AviMet LLWAS system for calculating the windshear
conditions. The LLWAS phase III windshear algorithm developed by NCAR for the U.S.
Federal Aviation Administration (FAA).
LLWAS screen
A screen in the WeatherView application displaying wind data, windshear alert data,
and microburst alert data in text format for the specified runways.
LLWAS processing status
The status text displayed in the LLWAS screen in the WeatherView application.
Indicates the status of sensor network. See degraded LLWAS processing status,
normal LLWAS processing status, and support LLWAS processing status.
maintenance personnel
Personnel at the airport responsible for taking care of the general functioning of the
AviMet system. At some airports, observers may take part in the maintenance tasks.
measurement site
See site.
Message Notification
A message type in Diagnostics application (only when the AviMet LLWAS system is
integrated with AviMet AWOS).
microburst
A small, very intense downdraft that descends to the ground, resulting in a strong
wind divergence. The size of the event is typically less than 4 kilometers across.
Microbursts are capable of producing winds of more than 100 mph, causing significant
damage. The life span of a microburst is around 5-15 minutes. See also microburst alert
and microburst conditions.
microburst alert
An alert generated in the WeatherView application when the calculated microburst
conditions exist. See also microburst and microburst conditions.
microburst conditions
Based on horizontal wind speed and wind direction measurements, the AviMet LLWAS
system uses the LLWAS phase III algorithm to compare the current wind situation
differences to airport-specific threshold values to determine if possible windshear
conditions exist. These calculated conditions are referred to as windshear conditions.
When the values exceed a specific microburst limit, the conditions are referred to as
microburst conditions. See also microburst alert, microburst, and LLWAS algorithm.
missing data status
A data status displayed in the weather data fields in the WeatherView application with
slashes in the data fields. Indicates that there is no data coming from the sensor due
to sensor or system problems.
NCAR
National Center for Atmospheric Research.
Low-Level Windshear Alert System User Guide M210885EN-K
74