Latest aviation applications of LIDAR at the Hong Kong International Airport

Doppler LIDAR systems have been used for operational weather alerting at the Hong Kong International Airport (HKIA) since their first introduction in 2002. Over the years, more applications have been developed for using LIDAR data in monitoring the weather conditions inside and around the airport. This paper summarizes the latest developments in the application of LIDAR, including the following:

(i) using the LIDAR-retrieved wind field in the identification of Lagrangian coherent structures (LCS) as a new development in the understanding of the structure of low-level windshear. In selected cases, the LCS so determined has reasonable correlation with the airflow disturbances experienced by the aircraft; (ii) apart from using the LIDAR's headwind profile, the windshear hazard factor, also called F-factor, has also been calculated based on the LIDAR data and processed through a flight simulator. The LIDAR-based F-factor so obtained has good correlation with the aircraft-based F-factor, and the performance of LIDAR-based F-factor in the alerting of low-level windshear has been determined using pilot windshear reports as an independent data sample; (iii) use of the LIDAR data to calculate turbulence intensity, or eddy dissipation rate (EDR) along the flight path. The EDRs so obtained shows very good correlation with those calculated based on the wind data from an instrumented aircraft in Hong Kong. The performance of LIDAR-based EDR in the alerting of turbulence would be discussed; (iv) use of the LIDAR backscattered data in the calculation of visibility map near HKIA. The calculation algorithm has been revised, and the performance of the existing and the revised algorithms would be compared.

This paper would present preliminary results on the above-mentioned developments.