Application of near-field beam-forming in large-aperture optical towed linear array

2016 ◽  
Author(s):  
Chunyan Sun ◽  
Heping Shen ◽  
Xiufen Qiu ◽  
Yile Liu
Keyword(s):  
Linear Array ◽  
Near Field ◽  
Beam Forming ◽  
Large Aperture

Analysis of Positioning Accuracy Based on Focused Beam Forming

2013 ◽  
Vol 441 ◽  
pp. 607-610
Author(s):  
Fang Niu ◽  
Juan Hui ◽  
Feng Li ◽  
Feng Yuan Zhang
Keyword(s):  
Sound Velocity ◽  
High Precision ◽  
Frequency Band ◽  
Linear Array ◽  
Near Field ◽  
Beam Forming ◽  
Precision Positioning ◽  
Positioning Accuracy ◽  
Velocity Impact ◽  
Focused Beam

The technology of focused beam forming is mainly used for solving some certain problems about high-precision passive positioning in near field. In view of the problem of positioning accuracy, this paper discusses the effects of factors on the width of focused peak and its changes with the factors. The result of study shows the longer arrays length and the higher frequency band of signal and the shorter distance to the target, the narrower width of focused peak, which means the higher the positioning accuracy. The influence of the errors on the positioning accuracy is also simulated and analyzed in this paper. It turned out that, when horizontal linear array is used in the positioning, the horizontal error from the placement of array and parts of array elements no working have little effect on the positioning accuracy for the reason of the horizontal directivity of the array. The vertical errors from the placement of array, from the measurement of depth of the sea and the sound velocity impact the positioning accuracy a bit more. With the analysis of positioning accuracy, it proves that the technology of focused beam forming can realize high-precision positioning in near field. Finally, several suggestions on improving the positioning quality are offered.

scholarly journals Micro Non-Uniform Linear Array (MNULA) for Ultrasound Plane Wave Imaging

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 640
Author(s):  
Yujia Tang ◽  
Zhangjian Li ◽  
Yaoyao Cui ◽  
Chen Yang ◽  
Jiabing Lv ◽  
...  
Keyword(s):  
Plane Wave ◽  
Linear Array ◽  
Near Field ◽  
Uniform Linear Array ◽  
Imaging Technology ◽  
Linear Arrays ◽  
Imaging Quality ◽  
Imaging Results ◽  
Wave Imaging ◽  
Laboratory Technology

Ultrasound plane wave imaging technology has been applied to more clinical situations than ever before because of its rapid imaging speed and stable imaging quality. Most transducers used in plane wave imaging are linear arrays, but their structures limit the application of plane wave imaging technology in some special clinical situations, especially in the endoscopic environment. In the endoscopic environment, the size of the linear array transducer is strictly miniaturized, and the imaging range is also limited to the near field. Meanwhile, the near field of a micro linear array has serious mutual interferences between elements, which is against the imaging quality of near field. Therefore, we propose a new structure of a micro ultrasound linear array for plane wave imaging. In this paper, a theoretical comparison is given through sound field and imaging simulations. On the basis of primary work and laboratory technology, micro uniform and non-uniform linear arrays were made and experimented with the phantom setting. We selected appropriate evaluation parameters to verify the imaging results. Finally, we concluded that the micro non-uniform linear array eliminated the artifacts better than the micro uniform linear array without the additional use of signal processing methods, especially for target points in the near-field. We believe this study provides a possible solution for plane wave imaging in cramped environments like endoscopy.

Localisation of mixed near‐field and far‐field sources using the largest aperture sparse linear array

2018 ◽  
Vol 12 (2) ◽  
pp. 155-162 ◽  
Author(s):  
Ali Akbar Ebrahimi ◽  
Hamid Reza Abutalebi ◽  
Mahmood Karimi
Keyword(s):  
Linear Array ◽  
Near Field ◽  
Far Field ◽  
Sparse Linear Array

High Resolution Near-field Localization Method based on a Special Combination Linear Array

2021 ◽  
Author(s):  
An Yanyan ◽  
Shang Zhigang ◽  
Yang Fengmao ◽  
Zhang Bo ◽  
Wang Yongjiao
Keyword(s):  
High Resolution ◽  
Linear Array ◽  
Near Field ◽  
Localization Method ◽  
Field Localization

Near- and far-field beam forming using a linear array in deep and shallow water

2014 ◽  
Vol 135 (4) ◽  
pp. 2393-2393
Author(s):  
Richard L. Culver ◽  
Brian E. Fowler ◽  
D. Chris Barber
Keyword(s):  
Shallow Water ◽  
Linear Array ◽  
Beam Forming ◽  
Far Field

Near-Field Pattern of Large Aperture Higher Order Mode Generator Using Backpropagated Fields in Free Space

2014 ◽  
Vol 42 (4) ◽  
pp. 937-943 ◽  
Author(s):  
Kwanghoon Kim ◽  
Mun Seok Choe ◽  
Woosang Lee ◽  
Joonho So ◽  
Eunmi Choi
Keyword(s):  
Free Space ◽  
Near Field ◽  
Higher Order ◽  
Field Pattern ◽  
Order Mode ◽  
Large Aperture ◽  
Higher Order Mode
Sign in / Sign up

Export Citation Format

Share Document