Camera Array Synthetic Aperture Focusing and Fusion Based Hidden Object Imaging

2012 ◽  
pp. 660-667
Author(s):  
Tao Yang ◽  
Xiaoqiang Zhang ◽  
Lingyan Ran ◽  
Rui Yu ◽  
Runping Xi
Keyword(s):  
Synthetic Aperture ◽  
Camera Array ◽  
Synthetic Aperture Focusing ◽  
Object Imaging

scholarly journals Analysis of Moving Object Imaging from Compressively Sensed SAR Data in the Presence of Dictionary Mismatch

2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Ahmed Shaharyar Khwaja ◽  
Muhammad Naeem ◽  
Alagan Anpalagan
Keyword(s):  
Iterative Scheme ◽  
Reconstruction Error ◽  
Synthetic Aperture ◽  
Moving Target ◽  
Target Imaging ◽  
Cause Of Error ◽  
Moving Target Imaging ◽  
Velocity Mismatch ◽  
Object Imaging ◽  
Better Than

We present compressed sensing (CS) synthetic aperture radar (SAR) moving target imaging in the presence of dictionary mismatch. Unlike existing work on CS SAR moving target imaging, we analyze the sensitivity of the imaging process to the mismatch and present an iterative scheme to cope with dictionary mismatch. We analyze and investigate the effects of mismatch in range and azimuth positions, as well as range velocity. The analysis reveals that the reconstruction error increases with the mismatch and range velocity mismatch is the major cause of error. Instead of using traditional Laplacian prior (LP), we use Gaussian-Bernoulli prior (GBP) for CS SAR imaging mismatch. The results show that the performance of GBP is much better than LP. We also provide the Cramer-Rao Bounds (CRB) that demonstrate theoretically the lowering of mean square error between actual and reconstructed result by using the GBP. We show that a combination of an upsampled dictionary and the GBP for reconstruction can deal with position mismatch effectively. We further present an iterative scheme to deal with the range velocity mismatch. Numerical and simulation examples demonstrate the accuracy of the analysis as well as the effectiveness of the proposed upsampling and iterative scheme.

ULTRASONIC IMAGING SYSTEM USING A 2D ENVELOPE BEAMFORMING TECHNIQUE: IN-HOMOGENEITIES LOCATION

2004 ◽  
Vol 12 (04) ◽  
pp. 571-585
Author(s):  
L. MEDINA ◽  
E. MORENO
Keyword(s):  
Imaging System ◽  
Side Lobe ◽  
Ultrasonic Pulse ◽  
Image Resolution ◽  
Synthetic Aperture ◽  
Water Tank ◽  
Synthetic Aperture Focusing ◽  
Longitudinal Resolution ◽  
Synthetic Aperture Focusing Technique ◽  
Beamforming Technique

An algorithm has been developed to implement synthetic aperture focusing technique for B-scan. This is made at a several transmitter/receiver locations to form a map of ultrasonic reflectivity on the insonified region, considering the path travelled by the ultrasonic pulse from the transducer to the target and back again. To reconstruct the image, a time domain beam-former is applied to the envelope of the detected signals. This method minimizes the side-lobe amplitude and the restriction of λ/2 distance between two adjacent transducer positions can be neglected without loosing image resolution. The present work is focused on the location of the in-homogeneities, caused by the presence of a phantom immersed in a water tank. The results are presented when the distance between two adjacent transducer positions are varied from 0.5λ to 2.5λ showing that the longitudinal resolution is not affected but the lateral resolution becomes poorer when the distance is about 2λ. The error in the longitudinal location of in-homogeneities is within the minimum detectable distance of the system, while the lateral location error is increased when the distance between any two adjacent transducer positions is larger than 1.5λ.

Synthetic Aperture Focusing Techniques in the Near Field of a Focused Transducer

1996 ◽  
pp. 2073-2079
Author(s):  
W. Masri ◽  
M. Mina ◽  
S. S. Udpa ◽  
L. Udpa ◽  
T. Xue ◽  
...  
Keyword(s):  
Near Field ◽  
Synthetic Aperture ◽  
Synthetic Aperture Focusing

scholarly journals An analytical approach to optimize radial synthetic aperture focusing for volumetric transrectal ultrasound imaging

2021 ◽  
Author(s):  
Hyunwoo Song ◽  
Jeeun Kang ◽  
Emad M. Boctor
Keyword(s):  
Ultrasound Imaging ◽  
Analytical Approach ◽  
Transrectal Ultrasound ◽  
Analytical Description ◽  
Design Criterion ◽  
Synthetic Aperture ◽  
Critical Parameters ◽  
Grating Lobe ◽  
Radial Plane ◽  
Synthetic Aperture Focusing

In this paper, we present a novel analytical approach to optimize radial synthetic aperture focusing framework for high-definite and high-sensitive volumetric transrectal ultrasound imaging (TRUS-rSAF). A closed-form analytical description of beam profile defines spatial resolution and grating lobe positions in the TRUS-rSAF imaging of radial plane and validated by a heuristic testing of the critical parameters. Given the theoretical foundation, we optimize the TRUS-rSAF system configuration to balance the spatial and temporal resolution, grating lobe artifacts, and signal-to-noise ratio (SNR) in radial plane with a design criterion to outperform a clinical volumetric TRUS (TRUS-REF) imaging. The results showed that the proposed analytical optimization provides significant improvements of imaging quality in radial plane even over an in-plane microconvex TRUS imaging. Therefore, our analytical approach provides a optimal framework for effective TRUS-rSAF imaging in clinics.

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