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Japan Aerospace Exploration Agency

Weather information technology


June 23, 2014

Assessing the Turbulence Information System "ALWIN" at Narita Airport

ALWIN wind information displayed on aircraft cockpit instruments
(image provided by Japan Airlines Co., Ltd.)

During the period of March 3 to May 9, 2014, JAXA and the Japan Meteorological Agency (JMA) conducted an evaluation of the new turbulence information system ALWIN (Airport Low-level Wind InformatioN) at Narita International Airport with the cooperation of airline companies JAL and ANA.
ALWIN is a system that uses airport weather Doppler lidar*2 already installed by the JMA to implement part of the technology of the "Low-Level Turbulence Advisory System" (LOTAS)*1 that JAXA has been developing. In order to allow aircraft to safely land at an airport, ALWIN provides real-time information to onboard pilots and dispatchers at the airport on the status of winds (direction, speed, wind shear, turbulence, etc.) in the landing paths of their aircraft. For this evaluation, the prototype ALWIN system was used to provide information on winds around the airport and in landing paths to dispatchers via internet and to pilots via a text-based datalink system known as ACARS installed in the cockpits.
Moving forward, the utility of the system will be improved by reflecting evaluation comments collected through questionnaires and meetings with pilots and dispatchers who used ALWIN. In addition, flight data from the aircraft that actually landed will be used to assess the effectiveness of ALWIN by comparing that wind data recorded on the aircraft to the wind information provided by ALWIN.

*1 LOTAS: a system which uses weather observation sensors (radar/lidar) installed at an airport to detect the low-altitude turbulences regardless of weather and provide pilots and airpor t flight dispatchers with information on turbulences, current and ten minutes in the future.
*2 Airport weather Doppler lidar: a device that measures the wind at low altitudes under non-precipitation conditions by using laser beams to detect the movement of aerosols (fine particles) in the atmosphere; currently installed at Japanese major airports such as Narita International Airport.