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In this work, a microwave photonic prototype for concurrent radar detection and spectrum sensing is proposed, designed, built, and investigated. A direct digital synthesizer and an analog electronic circuit are integrated to generate an…

Wavefront correction and beam tracking are critical in applications such as long-range imaging through turbulence and free-space optical communication. For instance, adaptive optics systems are employed to correct wavefront distortions…

The artificial noise (AN) aided multi-beam directional modulation (DM) technology is capable of wireless physical layer secure (PLS) transmissions for multiple desired receivers in free space. The application of AN, however, makes it less…

Signal Processing · Electrical Eng. & Systems 2019-08-14 Qian Cheng , Vincent Fusco , Jiang Zhu , Shilian Wang , Fanggang Wang

In this paper, we propose a novel method for frequency modulated continuous wave (FMCW) radar mutual interference mitigation (IM) based on the discrete fractional Fourier transform (DFrFT). Interference chirps are detected and mitigated by…

Signal Processing · Electrical Eng. & Systems 2026-04-30 Christian Oswald , Franz Pernkopf

Quantum noise limits the sensitivity of precision measurement devices, such as laser interferometer gravitational-wave observatories and axion detectors. In the shot-noise-limited regime, these resonant detectors are subject to a trade-off…

Quantum Physics · Physics 2021-06-16 Xiang Li , Jiri Smetana , Amit Singh Ubhi , Joe Bentley , Yanbei Chen , Yiqiu Ma , Haixing Miao , Denis Martynov

The next generation of large ground- and space-based optical telescopes will have segmented primary mirrors. Co-phasing the segments requires a sensitive wavefront sensor capable of measuring phase discontinuities. The Zernike wavefront…

Instrumentation and Methods for Astrophysics · Physics 2022-06-29 Maaike A. M. van Kooten , Sam Ragland , Rebecca Jensen-Clem , Yinzi Xin , Jacques-Robert Delorme , J. Kent Wallace

With increasing application of frequency-modulated continuous wave (FMCW) radars in autonomous vehicles, mutual interference among FMCW radars poses a serious threat. Through this paper, we present a novel approach to effectively and…

Signal Processing · Electrical Eng. & Systems 2023-01-02 Abhilash Gaur , Po-Hsuan Tseng , Kai-Ten Feng , Seshan Srirangarajan

This study proposes a radar-centric integrated sensing and communication (ISAC) system utilizing a two-layer modulation scheme for vehicular networks. Frequency-modulated continuous wave (FMCW) chirps are jointly modulated via phase…

Signal Processing · Electrical Eng. & Systems 2026-05-25 Murat Temiz , Colin Horne , Matthew A. Ritchie , Christos Masouros

The upcoming extremely large telescopes will have to deal with the so-called ''pupil fragmentation'' effect: for what concerns the Extremely Large Telescope (ELT), the presence of thick spider legs supporting the secondary mirror may induce…

Instrumentation and Methods for Astrophysics · Physics 2024-06-05 G. Carlà , L. Busoni , S. Esposito , G. Agapito , R. Holzlöhner

Dark wavefront sensing takes shape following quantum mechanics concepts in which one is able to "see" an object in one path of a two-arm interferometer using an as low as desired amount of light actually "hitting" the occulting object. A…

The concept of pyramid wavefront sensors (PWFS) has been around about a decade by now. However, there is still a great lack of characterizing measurements that allow the best operation of such a system under real life conditions at an…

Astrophysics · Physics 2009-11-13 D. Peter , M. Feldt , B. Dorner , T. Henning , S. Hippler , J. Aceituno

Optical aberrations prevent telescopes from reaching their theoretical diffraction limit. Once estimated, these aberrations can be compensated for using deformable mirrors in a closed loop. Focal plane wavefront sensing enables the…

In the last two decades many people have been searching for the optimal wavefront sensor as it can boost the performance of high-contrast imagining by orders of magnitude on the ELTs. According classical information theory, the optimal…

Instrumentation and Methods for Astrophysics · Physics 2023-10-18 Sebastiaan Y. Haffert , Jared R. Males , Olivier Guyon

Frequency-modulated continuous-wave (FMCW) radar plays a pivotal role in the field of remote sensing. The increasing degree of FMCW radar deployment has increased the mutual interference, which weakens the detection capabilities of radars…

Signal Processing · Electrical Eng. & Systems 2024-07-18 Ziang Zhang , Guangzhi Chen , Youlong Weng , Shunchuan Yang , Zhiyu Jia , Jingxuan Chen

We propose a method to track signals from quadrant photodiodes (QPD) in heterodyne laser interferometers that employ digital phase-locked loops for phase readout. Instead of separately tracking the four segments from the QPD and then…

Instrumentation and Detectors · Physics 2020-11-17 Gerhard Heinzel , Miguel Dovale Álvarez , Alvise Pizzella , Nils Brause , Juan José Esteban Delgado

In this paper, we propose a novel secure wireless transmission architecture that enables the co-existence of spatial field modulation (SFM) and digital bandpass modulation (DBM), utilizing multi-mode vortex waves and programmable…

Signal Processing · Electrical Eng. & Systems 2025-12-24 Yufei Zhao , Deyu Lin , Qian Zhang , Haoyang Shi , Hong Niu , Afkar Mohamed Ismail , Yong Liang Guan , Chau Yuen

Extreme adaptive optics (AO) is crucial for enabling the contrasts needed for ground-based high contrast imaging instruments to detect exoplanets. Pushing exoplanet imaging detection sensitivities towards lower mass, closer separations, and…

Earth and Planetary Astrophysics · Physics 2021-07-29 Benjamin L. Gerard , Vincent Chambouleyron , Rebecca Jensen-Clem , Jean-François Sauvage

Nowadays, waveforms of integrated sensing and communication (ISAC) are almost based on conventional communication and sensing signal, which bounds both the communication and sensing performance. To deal with this issue, in this paper, a…

Signal Processing · Electrical Eng. & Systems 2026-02-25 Xi Nan , Rugui Yao , Ye Fan , Ruikang Zhong , Xiaoya Zuo , Theodoros A. Tsiftsis , Alexandros-Apostolos A. Boulogeorgos

Arm-locking is a technique for stabilizing the frequency of a laser in an inter-spacecraft interferometer by using the spacecraft separation as the frequency reference. A candidate technique for future space-based gravitational wave…

Instrumentation and Methods for Astrophysics · Physics 2016-02-17 James Ira Thorpe , Kirk McKenzie

In this study, a novel transmission scheme is proposed to serve radar-sensing and communication objectives at the same time and allocated bandwidth. The proposed transmitted frame non-orthogonally superimposes two different waveforms, which…

Signal Processing · Electrical Eng. & Systems 2020-07-14 Mehmet Mert Sahin , Huseyin Arslan