Results 71 to 80 of about 18,596 (191)

Satellite quantum communications: Fundamental bounds and practical security

Physical Review Research, 2021
Satellite quantum communications are emerging within the panorama of quantum technologies as a more effective strategy to distribute completely secure keys at very long distances, therefore playing an important role in the architecture of a large-scale ...
Stefano Pirandola
doaj   +1 more source

Post‐Acquisition Image‐Based Localization for High Resolution Thermal and Visible/Shortwave Infrared Images With Application to the Lunar Trailblazer Mission

Earth and Space Science, Volume 13, Issue 5, May 2026.
Abstract The Lunar Trailblazer mission aimed to assess the presence of water on the lunar surface using imaging spectroscopy in visible shortwave infrared (VSWIR) coupled with high‐resolution multispectral imaging in thermal midwave‐infrared (MWIR), captured simultaneously over the same target from orbit around the Moon with two different instruments ...
Kevin D. Gauld, James L. Dickson, Tristam J. Warren, Jihoon Yang, Neil Bowles, Bethany L. Ehlmann   +5 more
wiley   +1 more source

Exit Chart Aided Irregular Convolutional Code Design for Iterative Downlink SDMA Systems using Imperfect Channel State Information [PDF]

, 2007
We analyze a precoded and iteratively detected downlink multiuser system employing imperfect Spatio-Temporal Channel Impulse Response at the Transmitters (ST-CIRT) with the aid of Extrinsic Information Transfer (EXIT) charts.
Wei, C.Y., Jin Wang, Wang, J., Chun-Yi Wei, Hanzo, L., Lajos Hanzo   +5 more
core   +1 more source

Observation and Coordination Needs for Current, Near‐Future, and Next Generation Earth‐Observing SAR Systems

Earth and Space Science, Volume 13, Issue 5, May 2026.
Abstract This paper summarizes an evaluation by experts of how coordination of Earth‐observing Synthetic Aperture Radar (SAR) missions among the world's space agencies could advance toward game‐changing scientific discoveries and fully realizing SAR's practical capability to address many issues facing society.
Cathleen E. Jones, Ake Rosenqvist, Björn Rommen, Magdalena Fitrzyk, Eric Rignot, Bernd Scheuchl, Yujie Zheng, Andrew Hooper, Mark Simons, Tomokazu Kobayashi, Paul Siqueira, Maurizio Santoro, Takeo Tadono, Laura Hess, Heather McNairn, Laura Frulla, Malin Johansson, Wolfgang Dierking, Line Rouyet, Annett Bartsch, Paco Lopez Dekker, Johnny A. Johannessen   +21 more
wiley   +1 more source

Multi-Connectivity Between Terrestrial and Non-Terrestrial MIMO Systems

IEEE Open Journal of the Communications Society
Communicating in a non-terrestrial network (NTN) has recently emerged as a promising technology to provide global seamless connectivity. Although low earth orbit (LEO) satellites in an NTN have been employed for providing ubiquitous coverage and high ...
Bodong Shang, Xiangyu Li, Zhuhang Li, Junchao Ma, Xiaoli Chu, Pingzhi Fan   +5 more
doaj   +1 more source

Computational analysis of GEO satellite communication performance [PDF]

E3S Web of Conferences
The paper is a detailed Monte Carlo simulation study of Bit Error Rate (BER) behaviour of the Binary Phase Shift Keying (BPSK) modulation across the Geostationary satellite communication links in the Earth Orbit.
Achar Varun, Naragund Pradeepkumar, P Pughal, V Nataraj   +3 more
doaj   +1 more source

The Lunar Trailblazer Lunar Thermal Mapper Instrument

Journal of Geophysical Research: Planets, Volume 131, Issue 5, May 2026.
Abstract The Lunar Thermal Mapper (LTM) instrument is a UK Space Agency funded infrared radiometer designed and built for the National Aeronautics and Space Administration Lunar Trailblazer mission launched in February 2025. LTM is a pushbroom imaging filter radiometer with 15 channels that cover the wavelength range from 6.25 to 100 μm with a 40–70 m ...
Neil E. Bowles, Bethany L. Ehlmann, Rory Evans, Tristram J. Warren, Henry H. Eshbaugh, Greg King, Waqas Mir, Namrah Habib, Katherine Shirley, Fraser Clarke, Cyril Bourgenot, Chris Howe, Keith Nowicki, Fiona H. M. Henderson, Christopher S. Edwards, Rachel L. Klima, Kerri Donaldson Hanna, Calina C. Seybold, Andrew T. Klesh, David R. Thompson, Elise Furlan, Elena Scire, Judy S. Adler, Nicholas Elkington, Aria Vitkova, Jon Temple, Simon Woodward   +26 more
wiley   +1 more source

Enhanced Detection of Martian Dust Devils From Rover Images Using Machine Learning

Journal of Geophysical Research: Planets, Volume 131, Issue 5, May 2026.
Abstract We present a new end‐to‐end pipeline for the detection of Martian dust devils in rover imagery that substantially expands current capabilities for atmospheric monitoring. Applied to 23,409 images from the Perseverance rover across 200 sols, our system identified 19 dust devils, 18 of which were previously undocumented.
Kacy Hatfield, John Santerre, Conor A. Nixon   +2 more
wiley   +1 more source

Optical Satellite Downlinks to Optical Ground Stations and High-Altitude Platforms

, 2008
We have calculated the practical advantage of optical downlinks from earth observation (EO) satellites over conventional RF-downlinks in different downlink scenarios, taking into account blockage by cloud cover.
Giggenbach, Dirk, Moll, Florian, Horwath, Joachim, Epple, Bernhard   +3 more
core  

Satellite downlink scheduling problem: A case study

, 2015
The synthetic aperture radar (SAR) technology enables satellites to efficiently acquire high quality images of the Earth surface. This generates significant communication traffic from the satellite to the ground stations, and, thus, image downlinking ...
Snezana Mitrovic Minic, Abraham P. Punnen, Punnen, AP, Malladi, KT, Karapetyan, D, Mitrovic Minic, S, Krishna T. Malladi, Daniel Karapetyan   +7 more
core   +1 more source