Near-Field 3D SAR Imaging Using a Scanning Linear MIMO Array With Arbitrary Topologies

Abstract

For near-field synthetic aperture radar (SAR) imaging, frequency domain imaging algorithms typically require the array elements to be uniformly arranged to facilitate the application of fast Fourier transform (FFT) operations; this greatly restricts the array types that can be used for practical applications. For arrays with non-uniformly positioned antennas, no general and efficient imaging algorithm is available yet. To address this issue, an effective algorithm for efficient three-dimensional (3D) SAR imaging with arbitrary linear multi-input-multi-output (MIMO) array topologies is proposed. Specifically, non-uniform FFT (NUFFT) technology is utilized to tackle the non-uniform sampling issues in both the spatial and the wavenumber domain. Despite the intuitive idea, to achieve satisfied imaging, some issues are non-trivial and should be carefully addressed. Both simulations and experiments show the superiority of the proposed algorithm on computational complexity while maintain the same high imaging precision compared with the back-projection algorithm (BPA). Moreover, we suggest that the concept of NUFFT-based imaging can also be generalized to other imaging regimes with arbitrary array configurations. INDEX TERMS Radar imaging, multi-input-multi-output, synthetic aperture, array topology, millimeterwave imaging.

Research on Rebound Jamming Against Multi-Input Multi-Output Synthetic Aperture Radar

“…The following conclusions can be obtained: (1) Compare with the single channel SAR, jamming MIMO-SAR system by rebound method is more difficulty, but the rebound jamming is still an effective method. (2) The difference in the position of the transceiver elements will lead to the need for additional doppler frequency shift in the modulation function of the rebound jammer, but due to the limitation of the antenna size, the effect is small. (3) For the multi-carrier MIMO-SAR system, measurement error of sub-carrier frequency will lead to the position shift of the false target in range, and the main lobe broaden in azimuth.…”

“…MIMO-SAR system uses multiple antennas to radiate orthogonal signals to target region and multiple antennas to receive ground objects scattering echoes, which can obtain more ground information and form more equivalent phase centers than conventional Synthetic Aperture Radar (SAR), so that spatial sampling can replace time sampling and highresolution imaging can be achieved by combining sub-band synthesis technology [1]- [2]. MIMO-SAR emits orthogonal waveform, which reduces the probability of signal interception.…”

Development and Demonstration of MIMO-SAR mmWave Imaging Testbeds

“…Practical MIMO-SAR systems typically combine an array of transceivers with mechanical scanning for high-resolution imaging. In most common MIMO-SAR configurations [32], [49]- [51], a planar aperture is synthesized by mechanically moving a linear MIMO array continuously along a horizontal track pattern, as shown in Fig. 1.…”

“…Taking (31) and (32) into (29), and taking the Fourier transform on both sides with respect to x (the distinction between the primed and unprimed coordinate systems are dropped) and y R yield [31]…”

Concealed Object Detection and Recognition System Based on Millimeter Wave FMCW Radar

“…After receiving the echo signal of the target at different positions, the intermediate frequency (IF) signal is obtained by radar correlative demodulation and stored; the raw data is then uploaded to the host. In this way, the aperture of the antenna can be increased, which can be regarded as a column of the horizontal antenna array [14]. In the course of a radar Z scan, the MIMO-SAR radar is used to improve image resolution and reduce imaging cost compared to using a multi-radar imaging system.…”