Skip to main content

Free Content Application of LIDAR-based F-factor in windshear alerting

Download Article:
(PDF 1,225.1 kb)


The use of windshear hazard factor, also called F-factor, in the alerting of low-level windshear at the Hong Kong International Airport (HKIA) is studied in this paper, by calculating the F-factor using the headwind profiles measured by Doppler Light Detection And Ranging (LIDAR) systems. The LIDAR headwind profiles are processed through a flight simulator. The resulting winds are used to calculate the headwind gradient term of F-factor. The quality of such LIDAR-based F-factor is first studied by comparing with the aircraft-based F-factor. It turns out that, as long as the headwind data from the LIDAR and the aircraft have good correlation with each other, the F-factors from the two platforms are correlated well at the same time. Among the two commonly used arrival runway corridors of HKIA, the arrival corridor to the north runway of HKIA (location in Figure 1) from the west has better correlation for the F-factor. The performance of LIDAR-based F-factor in the alerting of low-level windshear is then studied by using the pilot windshear reports as the sky truth. The optimum threshold for F-factor alerting is established by striking a balance between the probability of detection (POD) of pilot windshear reports and the percentage of time on alert (POTA). It turns out that the negative maximum F-factor has better performance in the alerting of windshear than the positive F-factor value. The POD could reach 87 % wind a POTA of less than 10 %, which is suitable for operational use in the alerting of low-level windshear. The optimum F-factor threshold is about –0.05, which is smaller than the conventional value of –0.105 commonly adopted for onboard reactive windshear alerting system. The performance of LIDAR-based F-factor in the alerting of stronger windshear, namely, pilot reports of windshear magnitude of 25 knots (12.9 m/s) or 30 knots (15.4 m/s) or more, is also discussed in this paper.

Document Type: Research Article


Publication date: April 1, 2012

More about this publication?
  • Meteorologische Zeitschrift (originally founded in 1866) is the joint periodical of the meteorological societies of Austria, Germany and Switzerland. It accepts high-quality peer-reviewed manuscripts on all aspects of observational, theoretical and computational research out of the entire field of meteorology, including climatology. Meteorologische Zeitschrift represents a natural forum for the meteorological community of Central Europe and worldwide.
  • Editorial Board
  • Information for Authors
  • Submit a Paper
  • Subscribe to this Title
  • ingentaconnect is not responsible for the content or availability of external websites

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more