Vol. 14, no.1, 2022


Reconstruction of radio images from a multifrequency multistatic radio hologram using the nonequidistant FFT method

Vladimir I. Krainy, Aleksandr N. Semenov, Anastasiya A. Sergeeva

Bauman Moscow State Technical University, https://www.bmstu.ru/
Moscow 105005, Russian Federation
E-mail: vladk@bmstu.ru, semenov.an@bmstu.ru, nst-s@bmstu.ru

Received November 26, 2021, peer-reviewed December 11, 2021, accepted December 25, 2021

Abstract: The article considers the transformation of the back-projection method (focusing) for recovering geometry from the knowledge of the scattered field received with a multi-static radar system (multi-static radio hologram). It is shown that it can be expressed as a two-dimensional non-equidistant Discrete Fourier Transform (NDFT). An example of focusing a multi-frequency multi-static radio hologram of a flat multipoint object is given, and a reconstructed image is obtained based on the back-projection algorithm and the NDFT algorithms. A modification of NDFT based on the fast Gaussian gridding of non-uniform nodes (NuFFT), implemented in MATLAB, is used to speed up image reconstruction. A numerical experiment indicates similar reconstructed images obtained by the backpropagation method and with the two-dimensional NuFFT method. However, the NuFFT method was 740 times faster. The results show a significant reduction in computational cost with the NuFFT method focusing on multi-static radio holograms.

Keywords: radio image, antenna array, multistatic radio hologram, non-equidistant discrete Fourier transform

UDC 621.396

RENSIT, 2022, 14(1):21-26 DOI: 10.17725/rensit.2022.14.021.

Full-text electronic version of this article - web site http://en.rensit.ru/vypuski/article/431/14(1)21-26e.pdf