Results 11 to 20 of about 353 (143)
Programmable photonic unitary circuits for light computing. [PDF]
NanophotonicsAbstract Unitarity serves as a fundamental concept for characterizing linear and conservative wave phenomena in both classical and quantum systems. Developing platforms that perform unitary operations on light waves in a universal and programmable manner enables the emulation of complex light–matter interactions and the execution of general‐purpose ...
Kim K +5 more
europepmc +2 more sources
Fractional Fourier transforms of vortex Hermite-cosh-Gaussian beams
Results in Optics, 2021 In this paper, we investigate the propagation properties of a vortex Hermite-cosh-Gaussian beam (vHChGB) passing through a fractional Fourier transform (FRFT) optical system.
E.M. El Halba, Z. Hricha, A. Belafhal
doaj +1 more source
Continuous Time Frequency Domain Analysis of Ф-OTDＲ Nonstationary Signals
Journal of Harbin University of Science and Technology, 2021 Most of the natural vibration signals are stationary and modulated by the interference light signal of the distributed optical fiber vibration sensing system.
XU Tao, LI Li
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Frequency‐to‐spectrum mapping GAN for semisupervised hyperspectral anomaly detection
CAAI Transactions on Intelligence Technology, Volume 8, Issue 4, Page 1258-1273, December 2023., 2023 Abstract Most unsupervised or semisupervised hyperspectral anomaly detection (HAD) methods train background reconstruction models in the original spectral domain. However, due to the noise and spatial resolution limitations, there may be a lack of discrimination between backgrounds and anomalies.
Degang Wang +4 more
wiley +1 more source
IET Radar, Sonar &Navigation, Volume 17, Issue 12, Page 1796-1811, December 2023., 2023 This paper proposes a random pulse repetition interval and intra‐pulse frequency agile radar waveform and captures the range‐dimensional centroid feature of the echo. Accordingly, a jamming identification method based on the scale constrained Gaussian mixture model (SCGMM) and an entity radar target energy recovery algorithm based on the neighbourhood ...
Tai Guo +3 more
wiley +1 more source
IET Radar, Sonar &Navigation, Volume 17, Issue 10, Page 1558-1580, October 2023., 2023 (1) The range evolution rules with respect to time are derived and employed to formulate the target signal for two common manoeuvring motions, constant acceleration (CA) and constant turn (CT) motions in Cartesian coordinates. (2) Aiming at realising accurate energy accumulation and improving detection performance of CA and CT targets, two long‐time ...
Zeyu Xu, Gongjian Zhou
wiley +1 more source
IET Radar, Sonar &Navigation, Volume 17, Issue 9, Page 1420-1429, September 2023., 2023 Firstly, FRFT is used to process the wideband LFM signal, then the subspace orthogonality in the fractional Fourier domain is optimised, and finally the DOA estimation is obtained by weighting the sparse representation model objective function using subspace orthogonality.
Jun Zhong +4 more
wiley +1 more source
Electronics Letters, Volume 59, Issue 15, August 2023., 2023 We combine the TF information of the signal in the fractional domain with an optimization strategy to estimate the IF of multicomponent overlapping signals. The method converts the IF estimation into the problem of function fitting in the two‐dimensional plane.
Liyun Xu, Wei Li
wiley +1 more source
A novel sea clutter suppression method based on SVD‐FRFT at low signal‐to‐clutter ratio
Electronics Letters, Volume 59, Issue 14, July 2023., 2023 The target and sea clutter Doppler domains frequently overlap due to the frequent passage of slow ship targets through the sea clutter zone. In this letter, a novel sea clutter suppression method is suggested as a solution to this issue, whose key is a novel singular value zeroing criterion guided by the search results of two‐dimensional spectral peaks.
Qingyun Cheng +3 more
wiley +1 more source
Optics Express, 2018 In this paper, we demonstrated a novel thermal-wave radar imaging approach with use of a dual-directional (down then up) chirp (or linear frequency modulation, LFM) modulated laser as an external excitation source and signal processing by Fractional Fourier transform (FrFT), which can enhance the defect detectability and extend the depth-resolution ...
Fei, Wang +3 more
openaire +2 more sources