The Digital Airborne Imaging Spectrometer Experiment (DAISEX) was carried out for the European Space Agency (ESA) in order to develop the potential of spaceborne imaging spectroscopy for a range of different scientific applications. DAISEX involved simultaneous data acquisitions using different airborne imaging spectrometers over test sites in southeast Spain (Barrax) and the Upper Rhine valley (Colmar, France, and Hartheim, Germany). This paper presents the results corresponding to the column-integrated aerosol optical properties from ground-based spectroradiometer measurements over the Barrax area during the DAISEX campaign days in the years 1998, 1999, and 2000. The instruments used for spectral irradiance measurements were two Licor 1800 and one Optronic OL-754 spectroradiometers. The analysis of the spectral aerosol optical depth in the visible range shows in all cases the predominance of the coarse-particle mode over the fine-particle mode. The analysis of the back trajectories of the air masses indicates a predominance of marine-type aerosols in the lower atmospheric layers in all cases. Overall, the results obtained show that during the DAISEX there was a combination of maritime aerosols with smaller continental aerosols.