This paper details the preliminary outcome of research using GIS techniques and multiple datasets to evaluate the quality of contrail observations by citizens who participated in the Open Air Laboratories (OPAL) Climate Survey - a nationwide citizen science project. Unlike other citizen science studies in which 'experts' can revisit sites of observatoin, independent verification of contrails is difficult because of the ephemeral nature of the atmosphere. This research therefore uniquely uses datasets which reflect the complex and ever-changing 3D nature of the atmosphere and have been derived from a variety of sources (experts, models and amateur enthusiasts) with different spatial and temporal attributes.