Results 61 to 70 of about 2,705,955 (242)
Suppression of stimulated Raman scattering by angularly incoherent light, towards a laser system of incoherence in all dimensions of time, space, and angle [PDF]
arXiv, 2022 Laser-plasma instability (LPI) is one of the main obstacles in laser-driven inertial confinement fusion (ICF) for achieving predictable and reproducible fusion at high gain. For the first time we have proved analytically and confirmed with three-dimensional particle-in-cell simulations that angular incoherence has additional and much stronger ...
arxiv
Directed Energy Interception of Satellites [PDF]
, 2018 High power Earth and orbital-based directed energy (DE) systems pose a potential hazard to Earth orbiting spacecraft. The use of very high power, large aperture DE systems to propel spacecraft is being pursued as the only known, feasible method to achieve relativistic flight in our NASA Starlight and Breakthrough Starshot programs.
arxiv +1 more source
Signal design and processing for noise radar [PDF]
, 2022 An efficient and secure use of the electromagnetic spectrum by different telecommunications and radar systems represents, today, a focal research point, as the coexistence of different radio-frequency sources at the same time and in the same frequency ...
Galati, Gaspare +2 more
core +1 more source
Pre‐Fire Vegetation Conditions and Topography Shape Burn Mosaics of Siberian Tundra Fire Scars
Journal of Geophysical Research: Biogeosciences, Volume 130, Issue 3, March 2025.Abstract The fire season of 2020 in Siberia set a precedent for extreme wildfires in the Arctic tundra. Recent estimates indicated that the 2020 fires contributed 66% of the region's burned area over the last two decades. These fires burned in the carbon‐rich permafrost landscape, releasing vast amounts of carbon, and changing land surface processes by
N. Rietze +4 more
wiley +1 more source
Experimental Demonstration of Secure Frequency Hopping Communication Enabled by Quantum Key Distribution [PDF]
arXiv, 2023 We propose and experimentally demonstrate a method of frequency hopping spread spectrum communication using a quantum key distribution network to deliver the frequency hopping pattern for secure wireless communications. Results show low interception and jamming probabilities.
arxiv
Giant Pulses -- the Main Component of the Radio Emission of the Crab Pulsar [PDF]
Astron.Rep. 50 (2006) 55-61, 2006 The paper presents an analysis of dual-polarization observations of the Crab pulsar obtained on the 64-m Kalyazin radio telescope at 600 MHz with a time resolution of 250 ns. A lower limit for the intensities of giant pulses is estimated by assuming that the pulsar radio emission in the main pulse and interpulse consists entirely of giant radio pulses;
arxiv +1 more source
Analysis of Multimode Low-Probability-of-Intercept (LPI) Communications with Atmospheric Effects [PDF]
, 1996 This research expanded Low Probability of Intercept (LPI) communications analysis in two areas. First, multimode communication was included to account for ground to ground and air to ground links in addition to the standard air to air links traditionally
Ghordlo, Ala
core +1 more source
Journal of Biogeography, Volume 52, Issue 2, Page 294-303, February 2025.ABSTRACT Aim The purported defining features of chimpanzee (Pan troglodytes) biogeography are sometimes simplistic and contradictory, yet we rely on these metrics to shape conservation and management planning for this endangered ape. We analysed the cover and configuration of woody vegetation at the northern margins of the species' range in Senegal to ...
Stacy Lindshield +8 more
wiley +1 more source
IET Radar, Sonar &Navigation, Volume 19, Issue 1, January/December 2025.(1) To address the radar emitter OMR problem in open‐space environments, a stable and easily portable LPI radar emitter OMR method based on dictionary similarity, Open‐DS, is proposed. (2) Considering that the relationships between features are often nonlinear, a random Fourier transform is applied to the features. (3) ICD and ICS modules are designed,
Gangyin Sun +4 more
wiley +1 more source
Radar signal recognition exploiting information geometry and support vector machine
IET Signal Processing, 2023 Aiming at the recognition of low‐probability‐of‐intercept (LPI) radar signals, a support vector machine (SVM)‐based algorithm is proposed, where the information geometry theory is utilised to optimise the kernel function of the SVM.
Yuqing Cheng, Muran Guo, Limin Guo
doaj +1 more source