Terahertz Imaging for Detection of Corrosion and Defects Under Hull Coatings

In this Phase II SBIR project we propose to build and test a prototype non-contact time-domain terahertz non-destructive evaluation scanning system to acquire sub-surface images beneath hull coatings. The system will enable the rapid detection of hull defects such as corrosion and gouges hidden beneath hull coating; as well as hull coating material defects and hull coating adhesion defects. The Phase II prototype mobile scanning gantry concept incorporates features which will enable it to rapidly scan over large areas of actual hulls. The prototype will be suitable for both laboratory and field testing. The Phase II prototype will incorporate those features developed in Phase I to rapidly scan through the coating with sufficiently high resolution and contrast. In addition, several novel methods to enhance the contrast of defects will be tested in Phase II. The completed Phase II prototype system will be tested to evaluate the specificity of defect identification as specified URC MRO (unrestricted operation maintenance requirement card) in the laboratory using test samples configured to realistically represent a section of coated curved hulls with programmatic defects.