Wednesday, 23 January 2008
Performance of LIDAR-based turbulence detection algorithm
Exhibit Hall B (Ernest N. Morial Convention Center)
Turbulent airflow could occur at the Hong Kong International Airport (HKIA) when winds from the east to southwest climb over Lantau Island, a mountainous island to the south of the airport. Kwong and Chan (2007) shows that it is feasible to determine the profile of eddy dissipation rate (EDR) along the flight paths directly by using the LIDAR radial velocities obtained in glide-path scans at high spatial resolution. The possible application of the EDR profile for providing low-level turbulence alerts to the aircraft is studied in this paper by considering three typical cases of terrain-disrupted turbulent flow at HKIA, including spring-time easterly winds in a stable boundary layer and gale-force cross-mountain airflow associated with a typhoon. In comparison to the pilot reports of turbulence encounter, the LIDAR-based EDR profiles are found to give good indications of the occurrence of significant turbulence in general. The average value of the EDR profile also turns out to have high correlation with the EDR value from the Observatory's Windshear and Turbulence Warning System (WTWS).
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