Global probability of a cloud-free line of sight and continuous cloud size from 17 years (2006–2023) of CALIPSO satellite LiDAR data

Cloud-free line of sight is a strong performance driver for both active and passive electro-optic and infrared (EO/IR) systems. Ground-to-space clear lines of sight are becoming more critical with the expansion of space-laser communications which enable high data rates. Leveraging the Cloud Aerosol LiDAR and Infrared Pathfinder Satellite Observations (CALIPSO) cloud field data (2006–2023), we have calculated the altitude-dependent probability of a cloud-free line of sight [p(CFLOS)] and run statistical analyses on continuous cloud size (along satellite track—cloud chord length). Statistics for altitude-dependent p(CFLOS) are formed by aggregating satellite tracks into 2 deg× 2 deg bins. In addition, temporal analysis is performed to show monthly and seasonal changes by computing a sliding window average of the vertical cloud-free line of sight in each spatial location. The results can be used to inform planning activities for laser communications and deployment strategies for airborne operations that require clear or even clouded conditions for optimal data acquisition.