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We propose a decomposition method for the spectral peaks in an observed frequency spectrum, which is efficiently acquired by utilizing the Fast Fourier Transform. In contrast to the traditional methods of waveform fitting on the spectrum,…

Signal Processing · Electrical Eng. & Systems 2022-04-19 Kaan Gokcesu , Hakan Gokcesu

In portable, 3-D, or ultra-fast ultrasound (US) imaging systems, there is an increasing demand to reconstruct high quality images from limited number of data. However, the existing solutions require either hardware changes or…

Computer Vision and Pattern Recognition · Computer Science 2017-10-31 Yeo Hun Yoon , Jong Chul Ye

This paper addresses the problem of expressing a signal as a sum of frequency components (sinusoids) wherein each sinusoid may exhibit abrupt changes in its amplitude and/or phase. The Fourier transform of a narrow-band signal, with a…

Machine Learning · Computer Science 2013-02-27 Yin Ding , Ivan W. Selesnick

In this paper, the filter- and frequency-to-time mapping (FTTM)-based photonics-assisted time and frequency acquisition methods are comprehensively analyzed and the accuracy and resolution limitation in the fast sweep scenario is broken by…

Signal Processing · Electrical Eng. & Systems 2022-08-10 Pengcheng Zuo , Dong Ma , Xiaowei Li , Yang Chen

Optical absorption is usually considered deleterious, something to avoid if at all possible. We propose a broadband nanoabsorber that completely eliminates the diffracting wave, resulting in a subwavelength enhancement of the field.…

Optics · Physics 2017-03-31 Heeso Noh , Sebastien M. Popoff , Hui Cao

Sampling theory in fractional Fourier Transform (FrFT) domain has been studied extensively in the last decades. This interest stems from the ability of the FrFT to generalize the traditional Fourier Transform, broadening the traditional…

Information Theory · Computer Science 2024-04-30 Václav Pavlíček , Ayush Bhandari

Radio Frequency Interference (RFI) increasingly contaminates the radio astronomy spectrum, often exceeding astronomical signal amplitudes by 50-70 dB. Reliable detection and mitigation are therefore essential for studies of faint transient…

Instrumentation and Methods for Astrophysics · Physics 2026-05-08 Natalia A. Schmid , Sasanka Katreddi , Yechan Kweon

Image compression constitutes a significant challenge amidst the era of information explosion. Recent studies employing deep learning methods have demonstrated the superior performance of learning-based image compression methods over…

Computer Vision and Pattern Recognition · Computer Science 2024-05-07 Yuefeng Zhang , Kai Lin

This study introduces a short-time Fourier transform-based method for reconstructing signals encoded using modulo analog-to-digital converters with 1-bit folding information. In contrast to existing Fourier-based reconstruction approaches…

Signal Processing · Electrical Eng. & Systems 2026-01-14 Neil Irwin Bernardo

To obtain the initial pressure from the collected data on a planar sensor arrangement in Photoacoustic tomography, there exists an exact analytic frequency domain reconstruction formula. An efficient realization of this formula needs to…

Numerical Analysis · Mathematics 2015-01-14 Julian Schmid , Thomas Glatz , Behrooz Zabihian , Mengyang Liu , Wolfgang Drexler , Otmar Scherzer

Dispersive Fourier transformation is a powerful technique in which spectral information is mapped into the time domain using chromatic dispersion. It replaces a spectrometer with an electronic digitizer, and enables real-time spectroscopy.…

Optics · Physics 2009-11-13 J. Chou , D. R. Solli , B. Jalali

Fourier imaging is an indirect imaging method which records the diffraction pattern of the object scene coherently in the focal plane of the imaging system and reconstructs the image using computational resources. The spatial resolution,…

Optics · Physics 2023-06-05 Hui Yuan , Alvydas Lisauskas , Mark D. Thomson , Hartmut G. Roskos

By projecting onto complex optical mode profiles, it is possible to estimate arbitrarily small separations between objects with quantum-limited precision, free of uncertainty arising from overlapping intensity profiles. Here we extend these…

With the rapid development of microwave photonics, which has expanded to numerous applications of commercial importance, eliminating the emerging bottlenecks becomes of vital importance. For example, as the main branch of microwave…

Quantum Physics · Physics 2022-01-31 Yaqing Jin , Ye Yang , Huibo Hong , Xiao Xiang , Runai Quan , Tao Liu , Shougang Zhang , Ninghua Zhu , Ming Li , Ruifang Dong

We present a new computationally efficient method for multi-beamforming in the broadband setting. Our "fast beamspace transformation" forms $B$ beams from $M$ sensor outputs using a number of operations per sample that scales linearly (to…

Signal Processing · Electrical Eng. & Systems 2026-04-17 Nakul Singh , Coleman DeLude , Mark Davenport , Justin Romberg

We develop an iterative, adaptive frequency sensing protocol based on Ramsey interferometry of a two-level system. Our scheme allows one to estimate unknown frequencies with a high precision from short, finite signals. It avoids several…

Applied Physics · Physics 2023-08-16 Avishek Chowdhury , Anh Tuan Le , Eva M. Weig , Hugo Ribeiro

Resampling by interpolation is the traditional method to process interferograms from non-uniformly sampled Fourier transform spectrometers. The non-uniform fast Fourier transform (NUFFT) is an alternative approach that has been mostly…

Instrumentation and Detectors · Physics 2024-12-10 Muqian Wen , John Houlihan

In this paper, we provide a Graph Fourier Transform based approach to downsample signals on graphs. For bandlimited signals on a graph, a test is provided to identify whether signal reconstruction is possible from the given downsampled…

Other Statistics · Statistics 2016-12-23 Nileshkumar Vaishnav , Aditya Tatu

Image signals typically are defined on a rectangular two-dimensional grid. However, there exist scenarios where this is not fulfilled and where the image information only is available for a non-regular subset of pixel position. For…

Image and Video Processing · Electrical Eng. & Systems 2022-07-15 Jürgen Seiler , André Kaup

The spectral resolution of broadband Fourier-transform coherent anti-Stokes Raman spectroscopy is limited by the maximum optical path length difference that can be scanned within a short time in an interferometer. However, alternatives to…