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Photometric instruments operating at far infrared to millimetre wavelengths often have broad spectral passbands (central wavelength/bandwidth ~ 3 or less), especially those operating in space. A broad passband can result in significant…

The specification of the upper atmosphere strongly relies on solar proxies that can properly reproduce the solar energetic input in the UV. Whilst the microwave flux at 10.7 cm (also called F10.7 index) has been routinely used as a solar…

Solar and Stellar Astrophysics · Physics 2014-02-18 Thierry Dudok de Wit , Sean Bruinsma , Kiyoto Shibasaki

The number of active and non active satellites in Earth orbit has dramatically increased in recent decades, requiring the development of novel surveillance techniques to monitor and track them. In this paper, we build upon previous…

Instrumentation and Methods for Astrophysics · Physics 2020-04-01 Steve Prabu , Paul J Hancock , Xiang Zhang , Steven J Tingay

A point cloud enhancement method for 4D mmWave radar imagery is proposed in this paper. Based on the patch antenna and MIMO array theories, the MIMO array with small redundancy and high SNR is designed to provide the probability of high…

Image and Video Processing · Electrical Eng. & Systems 2024-01-31 Qingmian Wan , Hongli Peng , Xing Liao , Kuayue Liu , Junfa Mao

We present an estimate of the performance that will be achieved during on orbit operations of the JWST Mid Infrared Instrument, MIRI. The efficiency of the main imager and spectrometer systems in detecting photons from an astronomical…

Instrumentation and Methods for Astrophysics · Physics 2015-08-19 Alistair Glasse , G. H. Rieke , E. Bauwens , Macarena Garcıa-Marın , M. E. Ressler , Steffen Rost , T. V. Tikkanen , B. Vandenbussche , G. S. Wright

Diffusing wave spectroscopy (DWS) can be employed as an optical rheology tool with numerous applications for studying the structure, dynamics and linear viscoelastic properties of complex fluids, foams, glasses and gels. To carry out DWS…

Soft Condensed Matter · Physics 2018-11-06 Chi Zhang , Mathias Reufer , Danila Gaudino , Frank Scheffold

Observations of the Sun at millimeter and submillimeter wavelengths offer a unique probe into the structure, dynamics, and heating of the chromosphere; the structure of sunspots; the formation and eruption of prominences and filaments; and…

We present observations of high-amplitude rapid (2 s) variability toward two bright, compact extragalactic radio sources out of several hundred of the brightest radio sources in one of the 30x30 deg MWA Epoch of Reionization fields using…

Usage of secondary cosmic muons to image the geological structures density distribution significantly developed during the past ten years. Recent applications demonstrate the method interest to monitor magma ascent and volcanic gas…

Deriving a well-constrained differential emission measure (DEM) distribution for solar flares has historically been difficult, primarily because no single instrument is sensitive to the full range of coronal temperatures observed in flares,…

Solar and Stellar Astrophysics · Physics 2014-06-25 Amir Caspi , James M. McTiernan , Harry P. Warren

Position and frequency switching techniques used for the removal of the bandpass dependence of radio astronomical spectra are presented and discussed in detail. Both methods are widely used, although the frequency dependence of the system…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 B. Winkel , A. Kraus , U. Bach

This paper describes the use of the Murchison Widefield Array, a low-frequency radio telescope at a radio-quiet Western Australian site, as a radar receiver forming part of a continent-spanning multistatic radar network for the surveillance…

Signal Processing · Electrical Eng. & Systems 2022-06-07 Brendan Hennessy , Robert Young , Steven Tingay , Ashley Summers , Daniel Gustainis , Brian Crosse , Marcin Sokolowski

The magnetic field of the solar wind near the Sun is very difficult to measure directly. Measurements of Faraday rotation of linearly polarized radio sources occulted by the solar wind provide a unique opportunity to estimate this magnetic…

Solar and Stellar Astrophysics · Physics 2015-06-04 X. P. You , W. A. Coles , G. B. Hobbs , R. N. Manchester

Here we present a proof of concept for the application of the Variance of Laplacian (VL) method in quantifying the sharpness of optical solar images. We conducted a comprehensive study using over 65,000 individual solar images acquired on…

Instrumentation and Methods for Astrophysics · Physics 2024-05-21 Chu Wing So , Edwin Lok Hei Yuen , Edgar Heung Fat Leung , Jason Chun Shing Pun

In order to assure a stable series of recorded images of sufficient quality for further scientific analysis, an objective image quality measure is required. Especially when dealing with ground-based observations, which are subject to…

Solar and Stellar Astrophysics · Physics 2020-11-11 Robert Jarolim , Astrid Veronig , Werner Pötzi , Tatiana Podladchikova

Polarimetric studies of pulsars at low radio frequencies provide important observational insights into the pulsar emission mechanism and beam models, and probe the properties of the magneto-ionic interstellar medium (ISM). Aperture arrays…

High Energy Astrophysical Phenomena · Physics 2019-08-07 Mengyao Xue , S. M. Ord , S. E. Tremblay , N. D. R. Bhat , C. Sobey , B. W. Meyers , S. J. McSweeney , N. A. Swainston

In order to put MIDI/VLTI observations of AGNs on a significant statistical basis, the number of objects had to be increased dramatically from the few prominent bright cases to over 20. For this, correlated fluxes as faint as ~ 150 mJy need…

Instrumentation and Methods for Astrophysics · Physics 2013-01-15 Leonard Burtscher , Konrad R. W. Tristram , Walter J. Jaffe , Klaus Meisenheimer

We test the accuracy of ALMA flux density calibration by comparing ALMA flux density measurements of extragalactic sources to measurements made by the Planck mission; Planck is absolutely calibrated to sub-percent precision using the dipole…

Instrumentation and Methods for Astrophysics · Physics 2022-01-27 Gerrit S. Farren , Bruce Partridge , Rüdiger Kneissl , Simone Aiola , Rahul Datta , Megan Gralla , Yaqiong Li

It has been proposed that coherent radio emission could be emitted during or shortly following a gamma-ray burst (GRB). Here we present a low-frequency ($170-200$ MHz) search for radio pulses associated with long-duration GRBs using the…

Metacalibration is a recently introduced method to accurately measure weak gravitational lensing shear using only the available imaging data, without need for prior information about galaxy properties or calibration from simulations. The…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-31 Erin S. Sheldon , Eric M. Huff