For the trade-off between the high azimuth resolution and the wide-range swath in the single-input single-output synthetic aperture ladar (SAL) system, the range swath of the SAL system is restricted to a narrow range, this paper proposes a multiple-input multiple-output (MIMO) synthetic aperture ladar system. The MIMO system adopts a low pulse repetition frequency (PRF) to avoid a range ambiguity for the wide-range swath and in azimuth adopts the multi-channel method to achieve azimuth high resolution from the unambiguous azimuth wide-spectrum signal, processed through adaptive digital beam-forming technology. Simulations and analytical results are presented.
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http://dx.doi.org/10.1364/AO.55.001401 | DOI Listing |
Nat Commun
January 2025
State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing, China.
Complex-valued neural networks process both amplitude and phase information, in contrast to conventional artificial neural networks, achieving additive capabilities in recognizing phase-sensitive data inherent in wave-related phenomena. The ever-increasing data capacity and network scale place substantial demands on underlying computing hardware. In parallel with the successes and extensive efforts made in electronics, optical neuromorphic hardware is promising to achieve ultra-high computing performances due to its inherent analog architecture and wide bandwidth.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Earth Observation Science, Faculty of Geo-information Science and Earth Observation (ITC), University of Twente, Overijssel, The Netherlands.
Accurate global glacier mapping is critical for understanding climate change impacts. Despite its importance, automated glacier mapping at a global scale remains largely unexplored. Here we address this gap and propose Glacier-VisionTransformer-U-Net (GlaViTU), a convolutional-transformer deep learning model, and five strategies for multitemporal global-scale glacier mapping using open satellite imagery.
View Article and Find Full Text PDFEpilepsia
December 2024
Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA.
Objective: The most common medically resistant epilepsy (MRE) involves the temporal lobe (TLE), and children designated as temporal plus epilepsy (TLE+) have a five-times increased risk of postoperative surgical failure. This retrospective, blinded, cross-sectional study aimed to correlate visual and computational analyses of magnetoencephalography (MEG) virtual sensor waveforms with surgical outcome and epilepsy classification (TLE and TLE+).
Methods: Patients with MRE who underwent MEG and iEEG monitoring and had at least 1 year of postsurgical follow-up were included in this retrospective analysis.
Sci Rep
December 2024
Department of Science Education, Kangwon National University, 1 Gangwondaehak-gil, Chuncheon-si, 24341, Gangwon-do, Republic of Korea.
The eruption in Fagradalsfjall Volcano, located in Reykjanes Peninsula, Iceland, from several centuries' dormant states, occurred for the first time on March 19, 2021. Observations of Fagradalsfjall Volcano were conducted in 2021, and the eruption period lasted for six months until 18 September 2021. Six days pair of interferograms were generated from ninety synthetic aperture radar (SAR) data.
View Article and Find Full Text PDFHeliyon
December 2024
Department of Geology, University of Dhaka, Dhaka, 1000, Bangladesh.
Bhasan Char has undergone noteworthy transformations in its geographical characteristics since its emergence in 2003. Driven by sediment transported by the Ganges-Brahmaputra-Meghna river system, the island has gradually transitioned from a stretched-out configuration to a more rounded shape primarily due to continuous accretion, while erosion has been minimal since 2012. Currently, the island is being prepared to accommodate over 1 million Forcefully Displaced Myanmar Nationals (FDMN) refugees.
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