English
Related papers

Related papers: An improved algorithm for separating clock delays …

200 papers

We present an algorithm that uses the distribution of photon arrival times to distinguish speckles from incoherent sources, like planets and disks, in high contrast images. Using simulated data, we show that our approach can overcome the…

Instrumentation and Methods for Astrophysics · Physics 2019-10-09 Alex B. Walter , Clinton Bockstiegel , Timothy D. Brandt , Benjamin A. Mazin

Many aspects of our societies now depend upon satellite telecommunications, such as those requiring Global Navigation Satellite Systems (GNSS). GNSS is based on radio waves that propagate through the ionosphere and experience complicated…

Space Physics · Physics 2025-11-19 Paul Kinsler , Biagio Forte

Estimating high resolution models of the Earth's core magnetic field and its time variation in the polar regions requires that one can adequately account for magnetic signals produced by polar ionospheric currents, which vary on a wide…

Space Physics · Physics 2023-09-11 Clemens Kloss , Christopher C. Finlay , Karl M. Laundal , Nils Olsen

Foregrounds with polarization states that are not smooth functions of frequency present a challenge to HI Epoch of Reionization (EoR) power spectrum measurements if they are not cleanly separated from the desired Stokes I signal. The…

Instrumentation and Methods for Astrophysics · Physics 2018-12-26 Zachary E. Martinot , James E. Aguirre , Saul A. Kohn , Immanuel Q. Washington

Time-delay cosmography can be used to infer the Hubble parameter $H_0$ by measuring the relative time delays between multiple images of gravitationally-lensed quasars. A few of such systems have already been used to measure $H_0$: their…

Instrumentation and Methods for Astrophysics · Physics 2022-08-03 L. Biggio , A. Domi , S. Tosi , G. Vernardos , D. Ricci , L. Paganin , G. Bracco

Vibrations, electromagnetic oscillations and temperature drifts are among the main reasons for dephasing in matter-wave interferometry. Sophisticated interferometry experiments, e.g. with ions or heavy molecules, often require integration…

A class of methods for measuring time delays between astronomical time series is introduced in the context of quasar reverberation mapping, which is based on measures of randomness or complexity of the data. Several distinct statistical…

Instrumentation and Methods for Astrophysics · Physics 2017-08-16 Doron Chelouche , Francisco Pozo Nuñez , Shay Zucker

Heterodyne laser phase measurements in a space-based gravitational wave interferometer are degraded by the phase fluctuations of the onboard clocks, resulting in unacceptable sensitivity performance levels of the interferometric data. In…

General Relativity and Quantum Cosmology · Physics 2015-08-19 Massimo Tinto , Nan Yu

Direction dependent calibration and imaging is a vital part of producing deep, high fidelity, high-dynamic range radio images with a wide-field low-frequency array like LOFAR. Currently, state-of-the-art facet-based direction dependent…

Instrumentation and Methods for Astrophysics · Physics 2020-03-25 J. G. Albert , R. J. van Weeren , H. T. Intema , H. J. A. Röttgering

For a ground-based radio interferometer observing at low frequencies, the ionosphere causes propagation delays and refraction of cosmic radio waves which result in phase errors in the received signal. These phase errors can be corrected…

Instrumentation and Methods for Astrophysics · Physics 2016-04-14 Poppy L. Martin , Justin D. Bray , Anna M. M. Scaife

It is the purpose of the paper to describe the virtues of time-frequency methods for signal processing applications, having astronomical time series in mind. Different methods are considered and their potential usefulness respectively…

Astrophysics · Physics 2009-11-07 R. Vio , W. Wamsteker

With the development of astronomical facilities, large-scale time series data observed by these facilities is being collected. Analyzing anomalies in these astronomical observations is crucial for uncovering potential celestial events and…

Machine Learning · Computer Science 2024-03-18 Xinli Hao , Yile Chen , Chen Yang , Zhihui Du , Chaohong Ma , Chao Wu , Xiaofeng Meng

Interferometers with single particles are susceptible for dephasing perturbations from the environment, such as electromagnetic oscillations or mechanical vibrations. On the one hand, this limits sensitive quantum phase measurements as it…

The sound field separation methods can separate the target field from the interfering noises, facilitating the study of the acoustic characteristics of the target source, which is placed in a noisy environment. However, most of the existing…

Audio and Speech Processing · Electrical Eng. & Systems 2019-07-24 Fei Ma , Wen Zhang , Thushara D. Abhayapala

The problem of denoising a one-dimensional signal possessing varying degrees of smoothness is ubiquitous in time-domain astronomy and astronomical spectroscopy. For example, in the time domain, an astronomical object may exhibit a smoothly…

Instrumentation and Methods for Astrophysics · Physics 2022-02-01 Collin A. Politsch , Jessi Cisewski-Kehe , Rupert A. C. Croft , Larry Wasserman

Group delay fringe tracking using spectrally-dispersed fringes is suitable for stabilising the optical path difference in ground-based astronomical optical interferometers in low light situations. We discuss the performance of group delay…

Astrophysics · Physics 2009-11-10 A. G. Basden , D. F. Buscher

The environmental perturbation on atoms is the key factor restricting the performance of atomic frequency standards, especially in long term scale. In this letter, we demonstrate a real-time noise distinguish operation of atomic clocks. The…

Atomic Physics · Physics 2016-04-19 Richang Dong , Jinda Lin , Rong Wei , Wenli Wang , Fan Zou , Yuanbo Du , Tingting Chen , Yuzhu Wang

Radar is a critical tool for maintaining knowledge of the many ob-jects in low Earth orbit and thus for maintaining confidence that societies around the world are secure against a variety of space-based threats. It is therefore important to…

Space Physics · Physics 2015-05-14 Mike Hapgood

Space-based gravitational-wave detectors, such as LISA, record interferometric measurements on widely separated satellites. Their clocks are not synced actively. Instead, clock synchronization is performed in on-ground data processing. It…

General Relativity and Quantum Cosmology · Physics 2025-04-16 Jan Niklas Reinhardt , Olaf Hartwig , Gerhard Heinzel