Results 1-4 of 4.
((uid:50040048))

Bookmark and Share    
Full Text
Peer Reviewed
See detailWidely Distributed Radar Imaging: Unmediated ADMM Based Approach
Murtada, Ahmed Abdelnaser Elsayed UL

in IEEE Journal of Selected Topics in Signal Processing (2022)

This paper presents a novel approach to reconstruct a unique image of an observed scene via synthetic apertures (SA) generated by employing widely distributed radar sensors. The problem is posed as a ... [more ▼]

This paper presents a novel approach to reconstruct a unique image of an observed scene via synthetic apertures (SA) generated by employing widely distributed radar sensors. The problem is posed as a constrained optimization problem in which the global image which represents the aggregate view of the sensors is a decision variable. While the problem is designed to promote a sparse solution for the global image, it is constrained such that a relationship with local images that can be reconstructed using the measurements at each sensor is respected. Two problem formulations are introduced by stipulating two different establishments of that relationship. The proposed formulations are designed according to consensus ADMM (CADMM) and sharing ADMM (SADMM), and their solutions are provided accordingly as iterative algorithms. We drive the explicit variable updates for each algorithm in addition to the recommended scheme for hybrid parallel implementation on the distributed sensors and a central processing unit. Our algorithms are validated and their performance is evaluated by exploiting the Civilian Vehicles Dome dataset to realize different scenarios of practical relevance. Experimental results show the effectiveness of the proposed algorithms, especially in cases with limited measurements. [less ▲]

Detailed reference viewed: 13 (4 UL)
Full Text
Peer Reviewed
See detailAccelerated Consensus ADMM for Widely Distributed Radar Imaging
Murtada, Ahmed Abdelnaser Elsayed UL; Mysore Rama Rao, Bhavani Shankar UL; Hu, Ruizhi UL et al

in 2022 IEEE Radar Conference (RadarConf22) Proceedings (2022)

Widely distributed radar systems are expected to enhance radar imaging performance due to their ability to capture diverse spatial scattering proprieties. Optimization-based sub-aperture imaging methods ... [more ▼]

Widely distributed radar systems are expected to enhance radar imaging performance due to their ability to capture diverse spatial scattering proprieties. Optimization-based sub-aperture imaging methods are used to adopt the isotropic scattering assumption within a narrow angular extent and reconstruct the scene image by fusing sub-aperture images. A previously proposed method based on consensus alternating direction method of multipliers (CADMM) provides a joint reconstruction of sub-aperture images along with a global image that represents the anisotropic scene. In this paper, we propose a modified version of CADMM which features lower complexity and faster convergence. By gradually learning the scene support during the iterative reconstruction, our proposed algorithm focuses on the image portion that contains the scattering targets and updates the sub-images accordingly. It also reduces the communication cost between the distributed sensors which need to exchange local image updates during CADMM iterations. [less ▲]

Detailed reference viewed: 10 (0 UL)
Full Text
Peer Reviewed
See detailAutomotive Squint-forward-looking SAR: High Resolution and Early Warning
Hu, Ruizhi UL; Mysore Rama Rao, Bhavani Shankar UL; Murtada, Ahmed Abdelnaser Elsayed UL et al

in IEEE Journal of Selected Topics in Signal Processing (2021)

Forward-looking automotive radars can sense long-distant targets to enable early warning, but the lateral resolution is limited. Synthetic aperture radar (SAR) techniques can achieve very high azimuth ... [more ▼]

Forward-looking automotive radars can sense long-distant targets to enable early warning, but the lateral resolution is limited. Synthetic aperture radar (SAR) techniques can achieve very high azimuth resolution but cannot resolve targets in the forward direction. As a trade-off, squint-forward-looking SAR (SFL-SAR) can perform 2D imaging on a distant area squint to the moving direction, providing both high resolution and early warning. In this paper, we analyzed and derived the constraints of automotive SFL-SAR to satisfy both the required resolution and braking distance. Simulations and imaging results verified the analysis. [less ▲]

Detailed reference viewed: 166 (18 UL)
Full Text
Peer Reviewed
See detailEfficient Radar Imaging Using Partially Synchronized Distributed Sensors
Murtada, Ahmed Abdelnaser Elsayed UL; Hu, Ruizhi UL; Alaeekerahroodi, Mohammad UL et al

in 2021 IEEE Radar Conference (RadarConf21), Atlanta, GA, USA May 2021 (2021)

Detailed reference viewed: 81 (9 UL)