English
Related papers

Related papers: Holographic Calibration of Phased Array Telescopes

200 papers

Large radio astronomy multi-element interferometers are frequently used as single dishes in a tied-array mode when signals from separate antennas are added. Phase shifts arising during wave propagation through a turbulent atmosphere can…

Instrumentation and Methods for Astrophysics · Physics 2015-03-17 P. A. Fridman

Holography has always held special appeal, for it is able to record and display spatial information in three dimensions. Here, we show how to augment the capabilities of digital holography by using a large number of narrow laser lines at…

We theoretically demonstrate the formation of different kinds of two-dimensional split-ring arrays in both triangular and square lattices by one-step holographic interference. The slit width of the split-ring can be adjusted by proper…

Optics · Physics 2009-11-13 G. Q. Liang , W. D. Mao , H. Zou , B. C. Chen , J. F. Cao , Y. Y. Pu , X. W. Wen , H. Z. Wang

The Differential Fourier Holography (DFH) gives an exact mathematical solution of the inverse problem of diffraction in the Fraunhofer regime. After the first publication [1] the Differential Fourier Holography was successfully applied in…

Optics · Physics 2016-04-20 Sergey G. Podorov , Eckhart Förster

Subwavelength grating micro-polarizer arrays, as a type of focal plane division simultaneous detection method, are significantly advancing the development and practical application of polarization imaging technology. Based on the…

Optics · Physics 2024-10-17 Tianshi Lu , Fuyuan Deng , Yufeng Wei , Zhipeng Zeng , Xinghui Li

In this work, an innovative method for controlling the current distribution of the radiating patch by adjusting the input phase is investigated to achieve both pattern and polarization reconfigurable characteristics for the multifunction. A…

Applied Physics · Physics 2023-09-06 Guangwei Yang , Qiao Cheng , Jianying Li , Shuai Zhang , Steven Gao , Xiaodong Chen

Digital holographic microscopy based on Gabor in-line holography is a well-known method to reconstruct both the amplitude and phase of small objects. To reconstruct the image of an object from its hologram, obtained under illumination by…

Optics · Physics 2009-11-04 S. G. Podorov , A. I. Bishop , D. M. Paganin , K. M. Pavlov

We propose a novel approach to site-resolved detection of a 2D gas of ultracold atoms in an optical lattice. A near resonant laser beam is coherently scattered by the atomic array and its interference pattern is holographically recorded by…

We present a multi-frequency far-field beam map for the 5m dish telescope at the Bleien Observatory measured using a commercially available drone. We describe the hexacopter drone used in this experiment, the design of the flight pattern,…

Instrumentation and Methods for Astrophysics · Physics 2015-11-18 Chihway Chang , Christian Monstein , Alexandre Refregier , Adam Amara , Adrian Glauser , Sarah Casura

Next generation radio observatories such as the MWA, LWA, LOFAR, CARMA and SKA provide a number of challenges for interferometric data analysis. These challenges include heterogeneous arrays, direction-dependent instrumental gain, and…

Astrophysics · Physics 2015-05-13 Miguel F. Morales , Michael Matejek

Due to the growing request from modern wireless applications of cost-affordable and high-gain scanning antenna solutions, the design of large phased arrays (PAs) with radiating elements organized into modular clusters with sub-array-only…

Systems and Control · Electrical Eng. & Systems 2025-08-14 Nicola Anselmi , Paolo Rocca , Giovanni Toso , Andrea Massa

The Low Frequency Array (LOFAR) is an ideal instrument to conduct deep extragalactic surveys. It has a large field of view and is sensitive to large scale and compact emission. It is, however, very challenging to synthesize thermal noise…

Distributed phased arrays have recently garnered interest in applications such as satellite communications and high-resolution remote sensing. High-performance coherent distributed operations such as distributed beamforming are dependent on…

Signal Processing · Electrical Eng. & Systems 2024-11-19 Matthew J. Dula , Naim Shandi , Jeffrey A. Nanzer

This work demonstrates an application of near field indirect microwave holography for the detection of malignant tissues in the human breast in an effective way. The holograms are recorded by two directive antennas aligned along each…

Hybrid beamforming via large antenna arrays has shown a great potential for increasing data rate in cellular networks by delivering multiple data streams simultaneously. In this paper, several beamforming design algorithms are proposed…

Information Theory · Computer Science 2018-02-06 Shahram Shahsavari , S. Amir Hosseini , Chris Ng , Elza Erkip

We demonstrate high-resolution non-iterative holographic coherent diffraction imaging with hard X-rays using a novel phase-shifting reference, fabricated by atomic layer deposition to produce nanosharp 3D structure. The method surpasses the…

Mesoscale and Nanoscale Physics · Physics 2016-10-17 Mirna Saliba , Jeroen Bosgra , Christoph Rau , Christian David , Aaron D. Parsons , Ulrich H. Wagner , Pierre Thibault

The performance of holographic multiple-input multiple-output (MIMO) communications, employing two-dimensional (2-D) planar antenna arrays, is typically compromised by finite degrees-of-freedom (DOF) stemming from limited array size. The…

Digital micromirror devices are a popular type of spatial light modulators for wavefront shaping applications. While they offer several advantages when compared to liquid crystal modulators, such as polarization insensitivity and…

Optics · Physics 2023-11-29 R. Gutiérrez-Cuevas , S. M. Popoff

Calibration of instrumental polarization is critical for measuring polarized radio emissions from astrophysical sources to extract the magnetic field information in astrophysical, heliospheric, and terrestrial plasmas. At meter wavelengths,…

Instrumentation and Methods for Astrophysics · Physics 2025-05-08 Devojyoti Kansabanik , Angelos Vourlidas , Soham Dey , Surajit Mondal , Divya Oberoi

Realizing the potential of 21 cm tomography to statistically probe the intergalactic medium before and during the Epoch of Reionization requires large telescopes and precise control of systematics. Next-generation telescopes are now being…

Instrumentation and Methods for Astrophysics · Physics 2016-08-17 Joshua S. Dillon , Aaron R. Parsons