Guest editorial: recent advances in non-destructive testing methods for geophysical surveys

A wide range of engineering and geoscience applications today rely on the extensive employment of specialist non-destructive testing (NDT) methods. The standalone use of these techniques has become established in many areas given the research progress achieved in the use of electrical, electromagnetic, optical and acoustic NDT methods. The capabilities and potential of these methods have been comprehensively explored and assessed, bringing research up to date. Research efforts have been mostly focussed on achieving new theoretical developments, the advancement of hardware and software components, and on finding new surveying and data processing methods and interpretations. As a result of this, the standard of quality is excellent, and data can be collected very accurately with available technology. At the same time, the concept of integration between sensing methodologies, in terms of modelling data of different scale domains and resolutions, is becoming a real challenge within the scientific community, and is starting to be recognised as a key research area that could drastically enhance the capabilities of existing NDT technology when faced with new and complex scenarios. This trend is driven by an increase in the demand for more effective solutions for the investigation of non-conventional scenarios. These investigations need to be carried out while maintaining reasonable costs and within feasible time requirements, as multiple methods and equipment and interdisciplinary expertise are involved.