scholarly journals The Australian Square Kilometre Array Pathfinder: Performance of the Boolardy Engineering Test Array

2016 ◽  
Vol 33 ◽  
Author(s):  
D. McConnell ◽  
J. R. Allison ◽  
K. Bannister ◽  
M. E. Bell ◽  
H. E. Bignall ◽  
...  
Keyword(s):  
Image Quality ◽  
Radio Telescope ◽  
Phased Array ◽  
Aperture Synthesis ◽  
Imaging Procedures ◽  
Test Array ◽  
Square Kilometre Array ◽  
Performance Sensitivity ◽  
Beam Characteristics ◽  
Beam Aperture

AbstractWe describe the performance of the Boolardy Engineering Test Array, the prototype for the Australian Square Kilometre Array Pathfinder telescope. Boolardy Engineering Test Array is the first aperture synthesis radio telescope to use phased array feed technology, giving it the ability to electronically form up to nine dual-polarisation beams. We report the methods developed for forming and measuring the beams, and the adaptations that have been made to the traditional calibration and imaging procedures in order to allow BETA to function as a multi-beam aperture synthesis telescope. We describe the commissioning of the instrument and present details of Boolardy Engineering Test Array’s performance: sensitivity, beam characteristics, polarimetric properties, and image quality. We summarise the astronomical science that it has produced and draw lessons from operating Boolardy Engineering Test Array that will be relevant to the commissioning and operation of the final Australian Square Kilometre Array Path telescope.

scholarly journals The Australian Square Kilometre Array Pathfinder: System Architecture and Specifications of the Boolardy Engineering Test Array

2014 ◽  
Vol 31 ◽  
Author(s):  
A. W. Hotan ◽  
J. D. Bunton ◽  
L. Harvey-Smith ◽  
B. Humphreys ◽  
B. D. Jeffs ◽  
...  
Keyword(s):  
Signal Processing ◽  
Radio Telescope ◽  
System Architecture ◽  
Phased Array ◽  
Wide Field ◽  
Test Array ◽  
Square Kilometre Array ◽  
Field Calibration ◽  
Calibration Methods ◽  
Pointed Observation

AbstractThis paper describes the system architecture of a newly constructed radio telescope – the Boolardy engineering test array, which is a prototype of the Australian square kilometre array pathfinder telescope. Phased array feed technology is used to form multiple simultaneous beams per antenna, providing astronomers with unprecedented survey speed. The test array described here is a six-antenna interferometer, fitted with prototype signal processing hardware capable of forming at least nine dual-polarisation beams simultaneously, allowing several square degrees to be imaged in a single pointed observation. The main purpose of the test array is to develop beamforming and wide-field calibration methods for use with the full telescope, but it will also be capable of limited early science demonstrations.

scholarly journals Plane Wave Imaging through Interfaces

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 4967
Author(s):  
Guillermo Cosarinsky ◽  
Jorge F. Cruza ◽  
Jorge Camacho
Keyword(s):  
Image Quality ◽  
Plane Wave ◽  
Phased Array ◽  
Mathematical Formulation ◽  
Non Destructive Testing ◽  
Arbitrary Geometry ◽  
Destructive Testing ◽  
Wave Imaging ◽  
Imaging Strategy ◽  
Non Destructive

Plane Wave Imaging (PWI) has been recently proposed for fast ultrasound inspections in the Non-Destructive-Testing (NDT) field. By using a single (or a reduced number) of plane wave emissions and parallel beamforming in reception, frame rates of hundreds to thousands of images per second can be achieved without significant image quality losses with regard to the Total Focusing Method (TFM) or Phased Array (PA). This work addresses the problem of applying PWI in the presence of arbitrarily shaped interfaces, which is a common problem in NDT. First, the mathematical formulation for generating a plane wave inside a component of arbitrary geometry is given, and the characteristics of the resultant acoustic field are analyzed by simulation, showing plane wavefronts with non-uniform amplitude. Then, an imaging strategy is proposed, accounting for this amplitude effect. Finally, the proposed method is experimentally validated, and its application limits are discussed.

Design of an Ultrasound Probe Holder to Minimize Motion Artifact During Sonography

2020 ◽  
Author(s):  
Smruti Mahapatra ◽  
Tarana Parvez Kaovasia ◽  
Sufia Ainechi ◽  
Ana Ainechi ◽  
Molly Acord ◽  
...  
Keyword(s):  
Image Quality ◽  
Ultrasound Image ◽  
Motion Artifact ◽  
Hand Movements ◽  
Operating Table ◽  
Imaging Procedures ◽  
Ultrasound Probe ◽  
3D Printed ◽  
Probe Holder ◽  
Minimize Motion Artifact

Abstract Standard diagnostic ultrasound imaging procedures heavily rely on a sonographer for image acquisition. Given the ultrasound probe is manually manipulated by the sonographer, there is a potential for noise artifacts like blurry acquired images caused by involuntary hand movements. Certain surgical procedures can also cause patients to exhibit involuntary “jumping” movements while on the operating table leading to further deterioration in ultrasound image quality. In this study, we attempt to mitigate these problems by fabricating a 3D-printed ultrasound probe holder. Due to the lightweight nature of the device, it can attach to surgical retractors without influencing the functionality of the retractor. Therefore, the 3D printed probe holder not only reduces relative motion between the probe and the patient, but also reduce the need for a sonographer during complex surgeries.

scholarly journals Status of the Thai 40-m Radio Telescope

2017 ◽  
Vol 13 (S337) ◽  
pp. 346-347
Author(s):  
Phrudth Jaroenjittichai
Keyword(s):  
Radio Telescope ◽  
Radio Astronomy ◽  
Time Domain ◽  
Phased Array ◽  
Low Frequency ◽  
Great Leap ◽  
Great Leap Forward ◽  
Astronomical Research ◽  
L Band ◽  
K Band

AbstractSince the first light of the 2.4-m Thai National Telescope in 2013, Thailand foresees another great leap forward in astronomy. A project known as “Radio Astronomy Network and Geodesy for Development” (RANGD) by National Astronomical Research Institute of Thailand (NARIT) has been approved for year 2017-2021. A 40-m radio telescope has been planned to operate up to 115-GHz observation with prime-focus capability for low frequency and phased array feed receivers. The telescope’s first light is expected in late 2019 with a cryogenics K-band and L-band receivers. RFI environment at the site has been investigated and shown to be at reasonable level. A 13-m VGOS telescope is also included for geodetic applications. Early single-dish science will focus on time domain observations, such as pulsars and transients, outbursts and variability of maser and AGN sources.

Multibeam Phased Array with Dynamic Focusing and Improved Image Quality

1996 ◽  
pp. 483-488
Author(s):  
S. G. Mesochorianakis ◽  
J. I. Burov ◽  
V. L. Strashilov ◽  
M. G. Christov
Keyword(s):  
Image Quality ◽  
Phased Array

scholarly journals PAFINDER – Searching for FRBs and pulsars using Phased Array Feeds

2017 ◽  
Vol 13 (S337) ◽  
pp. 370-371
Author(s):  
Mateusz Malenta ◽  
Ewan Barr ◽  
Aaron Chippendale ◽  
Xinping Deng ◽  
Daniel George ◽  
...  
Keyword(s):  
Real Time ◽  
Radio Telescope ◽  
Phased Array ◽  
Single Pulse ◽  
Radio Bursts ◽  
Pulse Detection ◽  
Phased Array Feeds

AbstractThe challenges of detecting and localising Fast Radio Bursts in real time can be met with the use of Phased Array Feeds. One such system, capable of creating up to 36 simultaneous beams, is currently being commissioned at the Effelsberg radio telescope in Germany following testing at the 64 m Parkes radio telescope. The PAFINDER (Phased Array Feed FRB Finder) pipeline will be used with this receiver to enable real–time single–pulse detection and localisation.

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