Patent ID: 9518918
Filing Date: 2016-12-13
CPC Classification: G01N

Claim Text:
1. A method of detecting the presence of anomalies in or on a substrate covered by a protective coating or layer, the method comprising: observing reflectivity from the substrate arising from incident electromagnetic waves produced from wide-angled illumination from a first incoherent passive source, the incident electromagnetic waves having millimeter or sub-millimeter wavelengths or having a frequency below about thirty terahertz; identifying the presence of anomalies in the substrate by at least one of: observing reflectivity from the substrate arising from incident electromagnetic waves produced from wide-angled illumination from an incoherent active source that is different to the first incoherent passive source, the incident electromagnetic waves from the incoherent active source having millimeter or sub-millimeter wavelengths or having a frequency below about thirty terahertz; and identifying the presence of anomalies in the substrate by contrasting spectral reflectivity profiles observed from the passive source and the active source.