SRAS (spatially resolved acoustic spectroscopy) a non-destructive acoustic microscopy microstructural-crystallographic characterization technique commonly used in the study of crystalline or polycrystalline materials. The technique can provide information about the structure and crystallographic orientation of the material. Traditionally, the information provided by SRAS has been acquired by using diffraction techniques in electron microscopy - such as EBSD. The technique was patented in 2005,  .
SRAS measures the surface acoustic wave velocity across a specimen, the surface acoustic wave (SAW) velocity is in turn a function of the material state, including parameters such as crystallographic orientation, elastic constants, temperature and stress.