Phase resolved shearography for remote sensing

摘要

A shearography system and method provide advances allowing for rapid processing to produce shearograms which provide surface motion information which may be helpful in multiple fields. For instance, amongst virtually endless possibilities, the system and method may allow for detection of underground structures or ordnance and or be used in the medical field to provide non-contact sensing of a person's internal structures or movements.

主权项

1. A method comprising the steps of:
reflecting sequentially off of a target surface first, second and third laser beams so that the first laser beam is reflected off of the target surface when the target surface is under a first load to produce a first reflected laser beam image; the second laser beam is reflected off of the target surface when the target surface is under a second load to produce a second reflected laser beam image; and the third laser beam is reflected off of the target surface when the target surface is under a third load to produce a third reflected laser beam image; wherein at least one of the first, second and third loads is different from another one of the first, second and third loads; phase stepping the first, second and third reflected laser beam images with a shearing interferometer to respective phases θ1, θ2 and θ3 of a laser beam wavelength; collecting with shearography equipment first, second and third specklegrams of the target surface based respectively on the first, second and third reflected laser beam images; and comparing the first, second and third specklegrams to one another to produce a first shearogram to ascertain surface changes of the target surface.