ACTRIS is an infrastructure improving atmospheric observations, developing new methods and protocols, and harmonizing existing observations. ACTRIS aerosol lidar data are variables measured with the recommended methodology (EARLINET standards and protocols).

LiCal is the official Lidar Calibration Centre for the Aerosol, Clouds and Trace gases Research Infrastructure (ACTRIS). LiCal is now open to weather services and aviation safety administrations, lidar/ceilometer developers, as well as to new lidar stations within the research community.

The various installations of LiCal have offered in the last years a significant number of accesses within EARLINET, ACTRIS, ESA-CEOS, ITaRS, as well as for the master and doctoral programs at the Romanian, Italian and German Universities, and national research programs.

EARLINET measurements must meet stringent stability and absolute accuracy standards to achieve the desired confidence in aerosol radiative forcing needs; thus, the network has developed a rigorous quality assurance program addressing both instrument performance and evaluation of the algorithms.