Results 91 to 100 of about 2,086,551 (203)

Planar Super‐Oscillation Diffractive Lenses: Practical Developments and Applications

Nanophotonics, Volume 15, Issue 16, 26 August 2026.
This review examines planar super‐oscillation diffractive lenses as a unified framework for super‐oscillatory lenses and supercritical lenses. It focuses on applications in super‐resolution imaging, micro/nanofabrication, and precision measurement and relates their application‐specific requirements to focal‐field control, multiobjective design ...
Yutian Cheng, Lingyi Tang, Xingcheng Xiao, Xiaochang Yu, Ya Guo, Yiting Yu, Wenli Li   +6 more
wiley   +1 more source

High-Resolution ISAR Imaging With Sparse Aperture VFM Waveforms Under Low SNR Condition

IEEE Access, 2019
In recent years, the compressed sensing theory has been widely used in sparse aperture radar imaging. The inverse synthetic aperture radar (ISAR) imaging based on the sparse aperture echo of V-style frequency modulation (V-FM) waveform, which can ...
Jiyuan Chen, Letao Xu, Xiaoyi Pan, Pu Zheng, Shunping Xiao   +4 more
doaj   +1 more source

Advanced Synthetic Aperture Radar Based on Digital Beamforming and Waveform Diversity [PDF]

, 2008
This paper introduces innovative SAR system concepts for the acquisition of high resolution radar images with wide swath coverage from spaceborne platforms.
Alberto Moreira, Moreira, Alberto, Nicolas Gebert, Younis, Marwan, Gebert, Nicolas, Krieger, Gerhard, Gerhard Krieger, Marwan Younis   +7 more
core   +1 more source

Space‐Time Coding Conformal Metasurfaces for Multifrequency Beam Steering and Shaping

Advanced Materials, Volume 38, Issue 45, 13 August 2026.
Space‐time coding conformal metasurfaces enable dynamic wave control on curved surfaces by combining programmable spatial patterns with temporal modulation. This study shows that a single conformal aperture can independently manipulate multiple frequency components, achieving multifunctional beam shaping and steering, with implications for ...
Filippo Pepe, Lei Zhang, Yi Ning Zheng, Xiao Qing Chen, Ivan Iudice, Giuseppe Castaldi, Marco Di Renzo, Tie Jun Cui, Vincenzo Galdi   +8 more
wiley   +1 more source

Maximum entropy regularization in inverse synthetic aperture radar imagery [PDF]

IEEE Transactions on Signal Processing, 1992
The method of maximum entropy is applied to the regularization of inverse synthetic aperture radar (ISAR) image reconstructions. This is accomplished by considering an ensemble of images with associated 'allowed' probability density functions. Instead of directly considering the 'solution' to be an image, the author takes it to be the a posteriori ...
openaire   +2 more sources

Benchmarking Coaxial and Angular Optical Emission Spectroscopy With Recommendations for Reliable Compositional In Situ Monitoring During Laser Powder Bed Fusion

Advanced Materials Technologies, Volume 11, Issue 16, 21 August 2026.
ABSTRACT Real‐time insight into local chemistry is critical for reliable part quality in additive manufacturing, especially laser powder bed fusion (PBF‑LB/M), where rapid thermal cycles and localized evaporation can undermine part performance. Optical emission spectroscopy (OES) offers non‑intrusive, in situ plume monitoring, but detection geometry ...
Philipp Gabriel, Bastian Jülich, Anna Rosa Ziefuss, Florian Eibl, Stephan Barcikowski   +4 more
wiley   +1 more source

Calibration Issue in SMART Synthetic Aperture Radar Based on Scan-On-Receive [PDF]

, 2009
A new spaceborne Synthetic Aperture Radar (SAR) system based on SCan-On-REceive (SCORE) algorithm has been recently proposed in order to overcome the trade-off between spatial resolution and swath wide of current SAR systems. The compound architecture of
Bordoni, Federica, Younis, Marwan, Krieger, Gerhard   +2 more
core  

A Novel Strategy for Radar Imaging Based on Compressive Sensing [PDF]

, 2010
Radar data have already proven to be compressible with no significant losses for most of the applications in which it is used. In the framework of information theory, the compressibility of a signal implies that it can be decomposed onto a reduced set of
López-Dekker, Paco, Mallorquí Franquet, Jordi Joan, Paco Lopez-Dekker, Tello Alonso, Marivi, Mallorquí, Jordi J., Jordi J Mallorqui, López Dekker, Francisco J., Marivi Tello Alonso, Tello Alonso, Mª Victoria   +8 more
core   +1 more source

Autofocus approach for sparse aperture inverse synthetic aperture radar imaging

Electronics Letters, 2015
In the inverse synthetic aperture radar imaging, the autofocus is a required step for generating high‐quality images. However, due to many factors, the aperture data may be sparse so that the classical motion compensation approaches and imaging algorithms are not proper. On the basis of the compressed sensing technique and two optimisation methods (the
Da Xiao, Fulin Su, Jianjun Gao
openaire   +1 more source

GLRT‐based detection of targets composed of distributed scattering centres

IET Radar, Sonar & Navigation
Attributed scattering problems have been found to be helpful in inverse synthetic aperture radar (ISAR) imaging and target recognition problems. In this model, the scattering centres are divided into two categories: localised and distributed.
Amir Mohammad Hatami, Seyyed Mohammad Karbasi, Mohammad Mahdi Nayebi   +2 more
doaj   +1 more source