Hierarchy classification:

1. top of the aat hierarchies
2. Activities Facet
3. Processes and Techniques (hierarchy name)
4. [processes and techniques by specific type]
5. analysis and testing techniques
6. interferometry

Anotations

Scope note:

Nondestructive evaluation technique similar to electron speckle pattern interferometry (ESPI) used to discover cracks, deformations, and other flaws in materials. It employs coherent laser light to create an interference pattern, or speckle, on the surface it illuminates. Shearography uses the test object itself as reference, creating a sheared, or double image, which superimposes the object with speckle pattern on the sample with reference light.