The analysis of European correlative experiments of the stratospheric aerosol layer is performed for three periods. These independent experiments are lidar measurements obtained at Garmisch-Partenkirchen, balloon measurements of the reflectance and of the polarization achieved at Aire sur l'Adour with RADIBAL experiment and transmission measurements provided by the SAGE II experiment. Comparisons of the aerosol slant optical thicknesses are performed, and the agreement is generally good. Two different schemes are used to retrieve two parameters of the size distribution from the polarization and from the transmission spectral measurements. The discrepancies that appear in a few cases of the radius comparison base are analyzed.