Cloud Fraction and Cloud Base Height from Doppler wind lidar

Cloud base height and cloud coverage information can be obtained from Doppler wind lidar measurements as clouds have strong backscatter. Doppler wind lidar PPI scans and vertical stares are used to detect clouds. Clouds are detected using a Haar wavelet to find sharp increases in backscatter with height. As a first approximation, cloud fraction from the lidar data can be assumed as a ratio of number of lidar beams with clouds detected to total number of beams over a 15 minute scan cycle. Because the instrument spends around half the time staring vertically, cloud fraction could be biased by overhead clouds. Cloud fraction variable is called skyCover in the netcdf file. Maximum of 3 layers of cloud base heights are identified. 

Note that cloud fraction and cloud base height products from Doppler wind lidar are work-in-progress and have not undergone peer review.

Variables:

skyCover: fraction of sky covered by clouds
decTime: number of days since January 0, 0000. Matlab defined timestamp
unixTime: number of seconds since January 1, 1970. Unix defined timestamp
cloudBase1: cloud base height 1
cloudBase2: cloud base height 2
cloudBase3: cloud base height 3
cloudFrac1: fraction of measurements at cloud base height 1 with clouds
cloudFrac2: fraction of measurements at cloud base height 2 with clouds
cloudFrac3: fraction of measurements at cloud base height 3 with clouds