A comparison between laser ceilometers at Hong Kong International Airport

Abstract

This article presents the results of a comparison between several ceilometers. The ceilometers at Hong Kong International Airport are due to be replaced, and this comparison was undertaken to ensure climatological continuity following the installation of a newer model. Cloud base height measurements are examined, and comparisons are made between the results from the different ceilometers, and between the ceilometer data and the data from a human observer. Quantile–quantile (EQQ) plots are also presented. The results provide assurance, through statistical analysis and consideration of case studies, that continuity of measurement can be achieved for clouds that are operationally significant in terms of aviation meteorology. It is also demonstrated that the new model of ceilometer has advantages over the existing models. The use of ceilometers for cloud amount measurement is also studied through comparison with human observations.