EARLINET Data Quality Check Procedure v3.1

This document describes version 3.1 of the EARLINET quality control procedures for aerosol lidar products stored in the ACTRIS/EARLINET database. It details the automated Basic Quality Controls (technical validation), Advanced Quality Controls (physical consistency checks), and introduces Multiproduct Quality Controls, which assess consistency among different products from the same measurement. The procedure supports data quality assessment, version management, and the assignment of quality levels to ensure the reliability and traceability of aerosol observations.