Articles | Volume 15
https://doi.org/10.5194/ars-15-283-2017
https://doi.org/10.5194/ars-15-283-2017
12 Dec 2017
 | 12 Dec 2017

Comparison of digital beamforming algorithms for 3-D terahertz imaging with sparse multistatic line arrays

Bessem Baccouche, Patrick Agostini, Falco Schneider, Wolfgang Sauer-Greff, Ralph Urbansky, and Fabian Friederich

Abstract. In this contribution we compare the back-projection algorithm with our recently developed modified range migration algorithm for 3-D terahertz imaging using sparse multistatic line arrays. A 2-D planar sampling scheme is generated using the array's aperture in combination with an orthogonal synthetic aperture obtained through linear movement of the object under test. A stepped frequency continuous wave signal modulation is used for range focusing. Comparisons of the focusing quality show that results using the modified range migration algorithm reflect these of the back-projection algorithm except for some degradation along the array's axis due to the operation in the array's near-field. Nevertheless the highest computational efficiency is obtained from the modified range migration algorithm, which is better than the numerically optimized version of the back-projection algorithm. Measurements have been performed by using an imaging system operating in the W frequency band to verify the theoretical results.

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Short summary
In this contribution we compare the back-projection algorithm with our recently developed modified range migration algorithm for 3D terahertz imaging using sparse multistatic line arrays. Numerical and experimental investigations show that imaging results from the proposed range migration algorithm approximates very nicely these of the back-projection algorithm, yet with a significant computational saving. These results are appealing for time critical 3D terahertz imaging.