Modified Wavenumber Domain Algorithm for Three-Dimensional Millimeter-Wave Imaging

Abstract

Abstract-Millimeter-wave (MMW) imaging techniques have been used for the detection of concealed weapons and contraband carried on personnel at airports and other secure locations. The combination of frequency-modulated continuous-wave (FMCW) technology and MMW imaging techniques should lead to compact, light-weight, and low-cost systems which are especially suitable for security and detection application.However, the long signal duration time leads to the failure of the conventional stop-and-go approximation of the pulsed system. Therefore, the motion within the signal duration time needs to be taken into account. Analytical threedimensional (3-D) backscattered signal model, without using the stop-and-go approximation, is developed in this paper.Then, a wavenumber domain algorithm, with motion compensation, is presented. In addition, conventional wavenumber domain methods use Stolt interpolation to obtain uniform wavenumber samples and compute the fast Fourier transform (FFT). This paper uses the 3-D nonuniform fast Fourier transform (NUFFT) instead of the Stolt interpolation and FFT. The NUFFT-based method is much faster than the Stolt interpolation-based method. Finally, point target simulations are performed to verify the algorithm.

Modified Cylindrical Holographic Algorithm for Three-Dimensional Millimeter-Wave Imaging

“…In [25], a modified rectilinear 3-D FMCW SAR imaging algorithm is presented. The main difference between the rectilinear imaging algorithm and the cylindrical imaging algorithm is that a convolution in the azimuth domain is needed for the latter.…”

Sparse Array Microwave 3-D Imaging: Compressed Sensing Recovery and Experimental Study

“…Hence, microwave 3-D imaging is typically an inverse scattering problem whereby a map of the reflectivity is reconstructed from the echo measurements of scattering flied, this task can be posed as finding sparse solutions to the linear equations. However, the classical methods for 3-D microwave imaging, such as the 3-D back-projection algorithm [1,10], the 3-D range migration algorithm [14], the chirp scaling algorithm [15], the 3-D omega-k algorithm [16] and the wave-number domain algorithm [17], etc., never exploit such prior sparsity knowledge. In addition, the resolutions of these conventional algorithms are limited by classical radar uncertainty principle.…”

A Study on Millimeter-Wave Imaging of Concealed Objects: Application Using Back-Projection Algorithm

“…For this purpose,various researchers have demonstrated both passive and active imaging systems [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. Passive imaging systems are based on the detection of natural radiation from the targets and reflection from the environment [9][10][11][12] and hence mostly limited to outdoor missions.…”

“…Besides, the lack of range information in the provided two-dimensional (2D) images puts an additional limit on the detection problem. On the other hand, active imaging systems [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] exploit various radar systems giving rise to indoor operation as well as sharp range resolving ability. Hence, the position and shape of the concealed objects can be attained from the produced threedimensional (3D) images.…”