Lens-Loaded Coded Aperture with Increased Information Capacity for Computational Microwave Imaging

Yurduseven, Okan; Abbasi, Muhammad Ali Babar; Fromentèze, Thomas; Fusco, Vincent

doi:10.3390/rs12091531

Cited by 21 publications

(29 citation statements)

References 43 publications

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“…An important aspect for the imaging problem at hand is the determination of the number of measurements (and hence aperture masks) to be used to retrieve the images of these targets to a good fidelity. The orthogonality of measurement modes produced by a CI system can be assessed by doing a singular value decomposition (SVD) analysis on the sensing matrix [25,17,43]. To this end, we first analyze the singular values of the sensing matrix as shown in Figure 7.…”

Section: Resultsmentioning

confidence: 99%

“…Combined with the hardware simplification facilitated by the CI technique, FPGAparallelization of the CI physical model exhibits a significant potential for reducing the computational latency of CI radars. It is worth mentioning that in spite of being shown for radar imaging, the validity of the presented approach is independent of the type of specific application considered, and this technique can be readily adopted across a wide application spectrum in CI, from security-screening [22,33,43] to automotive radars [4] and computational remote sensing techniques [6]. This is because the compression of the back-scattered data on the physical layer is the same for such applications.…”

Section: Discussionmentioning

confidence: 96%

“…A coded aperture can be considered as a computational aperture that can radiate spatio-temporally varying radiation patterns to probe the scene information [30,33]. A distinctive feature of this technique is that the radiation pattern of the aperture changes substantially as new imaging modes are generated [43]. The spatio-temporal modulation of the radiated fields probing the scene information is achieved by creating a set of dynamic masks to vary the field patterns radiated by the aperture [44,31,32].…”

Section: Computational Imaging Using Coded Aperturesmentioning

confidence: 99%

See 2 more Smart Citations

Hardware Enabled Acceleration of Near-Field Coded Aperture Radar Physical Model for Millimetre-Wave Computational Imaging

Sharma¹,

Yurduseven²,

Deka³

et al. 2021

PIER B

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There is an increasing demand in real-time imagery applications such as rapid response to disaster rescue and security screening to name a few. The throughput of a radar imaging system is mainly controlled by two parameters; data acquisition time and signal processing time. To minimize the data acquisition time, various methods are being tried and tested by researchers worldwide. Among them is the computational imaging (CI) technique, which relies on using coded apertures to encode the radar back-scattered measurements onto a set of spatio-temporally incoherent radiation patterns. Such a CI-based imaging approach eliminates the requirement for a raster scan and can substantially simplify the physical hardware architecture. Equally important is the processing time needed to retrieve the scene information from the coded back-scattered measurements. In CI, the simplification in the hardware layer comes at the cost of increased complexity in the signal processing layer due to the indirect mapping and compression of the scene information through the spatio-temporally incoherent transfer function of the coded apertures. To address this particular challenge, this paper presents a hardware-based solution for CI signal processing using a Field Programmable Gate Array (an Xilinx Virtex-7 (XC7VX485T) FPGA chip) architecture. In particular, the proposed method consists of calculating the CI sensing matrix using the FPGA chip and storing it on the FPGA platform for image reconstruction. For the adjoint operation, the calculated sensing matrix is applied on the measured back-scattered waves from the target object. We demonstrate that the FPGA based calculation can reach 21.9 times faster speed than conventional brute-force solutions.

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Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 96%

Section: Computational Imaging Using Coded Aperturesmentioning

confidence: 99%

See 1 more Smart Citation

Hardware Enabled Acceleration of Near-Field Coded Aperture Radar Physical Model for Millimetre-Wave Computational Imaging

Sharma¹,

Yurduseven²,

Deka³

et al. 2021

PIER B

Self Cite

View full text Add to dashboard Cite

show abstract

“…To this end, we first evaluate the orthogonality of the DMA radiated fields and correlation between them as a number of varying number of masks. For this purpose, a powerful technique is the singular value decomposition (SVD) of H. A rapid decay rate of the singular value spectrum (SVS) indicates a large level of correlation among measurements described by H [64]. By plotting these singular values, the slope of an SVD plot can be used to compare different imaging configurations and the role of different features in the imaging process [64].…”

Section: A Theory Of Polarimetric Imagingmentioning

confidence: 99%

Computational Polarimetric Imaging Using Two-Dimensional Dynamic Metasurface Apertures

Hoang

Fusco

Fromentèze

et al. 2021

IEEE Open J. Antennas Propag.

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In this paper, we present a two-dimensional dynamic metasurface aperture to perform computational polarimetric microwave imaging for the first time. First, a novel tunable dual-polarized metamaterial radiator element integrated with two PIN diodes is designed to radiate and capture cross-and co-polarized field components. The diodes placed in orthogonal positions are simultaneously switched on or off to configure the transmit and receive polarization states. In on state, the element radiated power is high whereas in off state, the element radiated power is low. By sparsely reconfiguring and random assignment of the developed metamaterial elements across the array aperture, dynamic modulation of the radiated fields is achieved. Using this principle, we synthesize polarimetric, spatio-temporally incoherent wave-chaotic modes that facilitate polarimetric computational imaging. Leveraging the novelty of the dual-polarized dynamic characteristics of the wave-chaotic radiation, polarimetric imaging is computed in the near-field region at K-band frequencies and the polarimetric responses of specific targets are retrieved. The approach is verified by electromagnetic full-wave simulations, and imaging a T-shaped object consisting of two orthogonal metal strips, it is demonstrated the target characteristics from a set of backscatter measurements compressed by the developed dynamic metasurface antenna can be retrieved both in co-and cross-polarimetric channels.

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“…This is a transmission metasurface antenna utilizing the gradient zoom coefficient design to generate frequency-diverse bunching radiation patterns. In 2020, O. Yurduseven proposed a lens-loaded coded aperture that can increase information capacity [27]. It is a cavity metasurface antenna with a semi-spherical shaped dielectric lens that can focus the beams on the target and improve the number of effective measurement modes.…”

Section: Introductionmentioning

confidence: 99%

Frequency-Diverse Metasurface Antenna With Hybrid Bunching Methods for Coincidence Imaging

et al. 2020

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A frequency-diverse metasurface antenna with hybrid bunching methods for coincidence imaging is proposed in this paper. The hybrid frequency-diverse bunching metasurface antenna contains an excitation system, a frequency-diverse metasurface and a double-layer-metal-plate bunching system. Firstly, the excitation system of the metasurface antenna is divided into two parts, the bunching-excitation module and the random-excitation module. The bunching-excitation module includes a seven-element coherent antenna array that can generate bunching beams with 80 degree beamwidth from 32GHz to 36GHz; and the random-excitation module includes eight antenna elements distributed evenly to excite the frequencydiverse metasurface in the same working bandwidth. A multilayer feed system is also designed utilizing the stripline structure to feed both the bunching-excitation module and the random-excitation module. Secondly, six kinds of metamaterial elements possessing disparate transmitted phases are selected to constitute the frequency-diverse metasurface. The frequency-diverse metasurface is loaded to the excitation system to generate the frequency-diverse radiation patterns. Then, in order to achieve a narrower bunching angle, a double-layer-metal-plate bunching system is designed. Furthermore, the performances of the proposed bunching metasurface antenna, including the radiation efficiency, the reflection coefficient and the correlation coefficients of radiation patterns at different frequencies are evaluated. Finally, the coincidence imaging experiment is carried out using the proposed hybrid bunching metasurface antenna and the image of the target is reconstructed successfully. The designed is verified by both simulations and measurements.

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Lens-Loaded Coded Aperture with Increased Information Capacity for Computational Microwave Imaging

Cited by 21 publications

References 43 publications

Hardware Enabled Acceleration of Near-Field Coded Aperture Radar Physical Model for Millimetre-Wave Computational Imaging

Hardware Enabled Acceleration of Near-Field Coded Aperture Radar Physical Model for Millimetre-Wave Computational Imaging

Computational Polarimetric Imaging Using Two-Dimensional Dynamic Metasurface Apertures

Frequency-Diverse Metasurface Antenna With Hybrid Bunching Methods for Coincidence Imaging

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