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Sparse arrays have been widely exploited in radar systems because of their advantages in achieving large array aperture at low hardware cost, while significantly reducing mutual coupling. However, sparse arrays suffer from high sidelobes…

Signal Processing · Electrical Eng. & Systems 2025-03-10 Ruxin Zheng , Shunqiao Sun , Hongshan Liu

Small-scale interplanetary magnetic flux ropes (SMFRs) are similar to ICMEs in magnetic structure, but are smaller and do not exhibit ICME plasma signatures. We present a computationally efficient and GPU-powered version of the…

We introduce a novel measurement method for the phase noise measurement of optical amplifiers, topologically similar to the Heterodyne Mach-Zehnder Interferometer but governed by different principles, and we report on the measurement of a…

The statistical behavior of the eigenvalues of the sample covariance matrix (SCM) plays a key role in determining the performance of adaptive beamformers (ABF) in presence of noise. This paper presents a method to compute the approximate…

Systems and Control · Computer Science 2018-08-06 Saurav R. Tuladhar , John R. Buck

We re-examine the technique of determining the redshifts of galaxies from the ratio of the submillimeter-to-radio continuum flux densities based on a recently published catalog of 850~$\mu$m sources. We derived the expected variation of…

Astrophysics · Physics 2015-06-24 T. N. Rengarajan , Tsutomu T. Takeuchi

We study Bayesian inverse problems with mixed noise, modeled as a combination of additive and multiplicative Gaussian components. While traditional inference methods often assume fixed or known noise characteristics, real-world…

Machine Learning · Computer Science 2025-10-17 Paul Hagemann , Robert Gruhlke , Bernhard Stankewitz , Claudia Schillings , Gabriele Steidl

Modern radio interferometers enable high-resolution polarization imaging, offering insights into cosmic magnetism through Rotation Measure (RM) synthesis. Traditional 2+1D RM synthesis treats the 2D spatial and 1D spectral transforms…

Instrumentation and Methods for Astrophysics · Physics 2025-08-27 Victor Gustafsson , Marcus Brüggen , Cyril Tasse , Torsten Enßlin , Shane O'Sullivan , Francesco de Gasperin

We present a Bayesian method for estimating instrumental noise parameters and propagating noise uncertainties within the global BeyondPlanck Gibbs sampling framework, and apply this to Planck Low Frequency Instrument (LFI) time-ordered…

Flow and Diffusion Distributed Structures (FDS) are stationary spatially periodic patterns that can be observed in reaction-diffusion-advection systems. These structures arise when the flow rate exceeds a certain bifurcation point provided…

Pattern Formation and Solitons · Physics 2007-11-19 Pavel V. Kuptsov , Razvan A. Satnoianu

We reconstruct the velocity field of incompressible flows given a finite set of measurements. For the spatial approximation, we introduce the Sparse Fourier divergence-free (SFdf) approximation based on a discrete $L^2$ projection. Within…

Fluid Dynamics · Physics 2021-10-13 Luis Espath , Dmitry Kabanov , Jonas Kiessling , Raúl Tempone

Motivated by non-linear, non-Gaussian, distributed multi-sensor/agent navigation and tracking applications, we propose a multi-rate consensus/fusion based framework for distributed implementation of the particle filter (CF/DPF). The CF/DPF…

Distributed, Parallel, and Cluster Computing · Computer Science 2012-09-06 Arash Mohammadi , Amir Asif

Focal Ratio Degradation (FRD) in fibres is a crucial factor to control in astronomical instruments in order to minimize light loss. As astronomical instrumentation has advanced, the integration of large populations of fibres has become…

Instrumentation and Methods for Astrophysics · Physics 2023-06-30 Weimin Sun , Xudong Chen , Jiabin Wang , Hang Jiang , Anzhi Wang , Qi Yan , Zhenyu Ma , Shengjia Wang , Tao Geng , Yue Zhong , Zhongquan Qu , Yunxiang Yan

Positive semidefinite matrix factorization (PSDMF) expresses each entry of a nonnegative matrix as the inner product of two positive semidefinite (psd) matrices. When all these psd matrices are constrained to be diagonal, this model is…

Signal Processing · Electrical Eng. & Systems 2021-07-07 Dana Lahat , Yanbin Lang , Vincent Y. F. Tan , Cédric Févotte

Phased array feeds (PAFs) for reflector antennas offer the potential for increased reflector field of view and faster survey speeds. To address some of the development challenges that remain for scientifically useful PAFs, including…

Instrumentation and Methods for Astrophysics · Physics 2015-05-14 Jonathan Landon , Michael Elmer , Jacob Waldron , David Jones , Alan Stemmons , Brian D. Jeffs , Karl F. Warnick , J. Richard Fisher , Roger D. Norrod

The performance of a particle filter (PF) in nonlinear and non-Gaussian environments is often affected by particle degeneracy and impoverishment problems. In this paper, these two problems are re-assessed using the concepts of importance…

Applications · Statistics 2019-10-16 Xingzi Qiang , Yanbo Zhu , Rui Xue

In this work, we propose a novel unsupervised deep learning model to address multi-focus image fusion problem. First, we train an encoder-decoder network in unsupervised manner to acquire deep feature of input images. And then we utilize…

Computer Vision and Pattern Recognition · Computer Science 2020-09-25 Boyuan Ma , Xiaojuan Ban , Haiyou Huang , Yu Zhu

The measurement of precise absolute fluxes for stellar sources has been pursued with increased vigor since the discovery of the dark energy and the realization that its detailed understanding requires accurate spectral energy distributions…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 Ralph C. Bohlin , Karl D. Gordon , P. -E. Tremblay

(abridged) We run a Faraday structure determination data challenge to benchmark the currently available algorithms including Faraday synthesis (previously called RM synthesis in the literature), wavelet, compressive sampling and…

With the rapid development of radar jamming systems, especially digital radio frequency memory (DRFM), the electromagnetic environment has become increasingly complex. In recent years, most existing studies have focused solely on either…

Signal Processing · Electrical Eng. & Systems 2025-06-10 Huake Wang , Xudong Han , Bairui Cai , Guisheng Liao , Yinghui Quan

Precise measurements in optical and atomic systems often rely on differential interferometry. This method allows to handle large and correlated phase noise contributions -- such as environmental vibrations, thermal fluctuations, or…

Quantum Physics · Physics 2025-03-25 Luca Pezzè , Andrea Santoni , Chiara Mazzinghi , Marco Fattori , Augusto Smerzi