Keynote about Full Field Data Fusion (FFDF) to characterize subsurface defects in composite structures. They briefly introduce thermoelastic stress analysis and discuss aspects such as: the combination of TSA with DIC and application to CFRP, the identification of non-adiabatic behaviour, the revelation of subsurface defects, the quantification of damage and finally the scale advance: application to sandwich structures ... aerostructure ... multiaxial tests