SAR Imaging for Inspection of Metallic Surfaces at Millimeter Wave Frequencies


Millimeter wave near-field nondestructive testing (NDT) and imaging techniques are well-suited for the inspection of exposed (bare) and coated metallic surfaces for detecting surface-breaking discontinuities such as cracks and corrosion under coatings. However, one drawback of near-field imaging is the long scan time due to the dense grid requirements at these high frequencies. This paper presents a novel imaging technique for NDT of metallic surface for detecting surface-breaking cracks. This technique incorporates wideband measurements, synthetic aperture radar (SAR) based imaging algorithms, and surface wave propagation. The proposed technique vastly reduces the required scan time to produce an image. This paper introduces the imaging technique and studies its efficacy using full-wave numerical electromagnetic simulations. Results of measurements at K-band (26.5-40 GHz) and V-band (50-75 GHz) are provided illustrating the feasibility of the proposed technique for rapid detection of metal surface discontinuities.

Meeting Name

IEEE International Instrumentation and Measurement Technology Conference: Instrumentation and Measurement for Sustainable Development (2014: May 12-15, Montevideo, Uruguay)


Electrical and Computer Engineering

Keywords and Phrases

Millimeter Wave; Near-Field Imaging; Surface Waves; Synthetic Aperture Radar; Crack Detection; Imaging Techniques; Metallic Compounds; Planning; Surface Measurement; Sustainable Development; Wave Propagation; Corrosion Under Coatings; Electromagnetic Simulation; Novel Imaging Techniques; Wideband Measurements

International Standard Book Number (ISBN)


International Standard Serial Number (ISSN)


Document Type

Article - Conference proceedings

Document Version


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© 2014 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 May 2014