Detection and size evaluation of corrosion precursor pitting using near-field microwave and millimeter wave nondestructive testing methods

Early detection of pitting is a critical issue in the maintenance of an aircraft and its structural components. Near-field microwave nondestructive testing (NDT) techniques have been successfully used for detection of corrosion under paint including very small laser machined pits. However, it is desirable to improve the spatial resolution associated with these techniques so that pits with dimensions in the range of a few hundreds of micrometers can be effectively detected. Consequently several microwave near-field probes were developed and studied for enhanced spatial resolution --Abstract, page iii