The Experts below are selected from a list of 230574 Experts worldwide ranked by ideXlab platform
David E Lewis - One of the best experts on this subject based on the ideXlab platform.
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advances in Space traveling wave tubes for nasa missions
Proceedings of the IEEE, 2007Co-Authors: Jeffrey D Wilson, Edwin G Wintucky, K R Vaden, Dale A Force, I L Krainsky, Rainee N Simons, Neal R Robbins, W L Menninger, D R Dibb, David E LewisAbstract:Significant advances in the performance and reliability of traveling-wave tubes (TWTs) utilized in amplifying Space Communication signals for NASA missions have been achieved over the last three decades through collaborative efforts between NASA and primarily L-3 Communications Electron Technologies, Inc. (L-3 ETI). This paper summarizes some of the key milestones during this period and includes development of TWTs for the Communications Technology Satellite, Cassini, and Lunar Reconnaissance Orbiter missions. Technical advances in computer modeling, design techniques, materials, and fabrication have enabled power efficiency to increase by almost 40% and the output power/mass figure-of-merit to increase by an order of magnitude during this period.
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advances in Space traveling wave tubes for nasa missions used for amplifying Space Communications signals these tubes continue to efficiently and reliably deliver high power and to outperform solid state components
2007Co-Authors: Jeffrey D Wilson, Edwin G Wintucky, K R Vaden, Dale A Force, I L Krainsky, Rainee N Simons, Neal R Robbins, W L Menninger, D R Dibb, David E LewisAbstract:Significant advances in the performance and reliability of traveling-wave tubes (TWTs) utilized in amplifying Space Communication signals for NASA missions have been achieved over the last three decades through collaborative efforts between NASA and primarily L-3 Communications Electron Technologies, Inc. (L-3 ETI). This paper summarizes some of the key milestones during this period and includes development of TWTs for the Communications Technology Satellite, Cassini, and Lunar Reconnaissance Orbiter missions. Technical advances in computer modeling, design techniques, materials, and fabrication have enabled power efficiency to increase by almost 40% and the output power/mass figure-of- merit to increase by an order of magnitude during this period.
Robert W Boyd - One of the best experts on this subject based on the ideXlab platform.
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simulating thick atmospheric turbulence in the lab with application to orbital angular momentum Communication
New Journal of Physics, 2014Co-Authors: Brandon Rodenburg, Mohammad Mirhosseini, Mehul Malik, Omar S Maganaloaiza, Michael Yanakas, Laura Maher, Nicholas K Steinhoff, Glenn A Tyler, Robert W BoydAbstract:We describe a procedure by which a long () optical path through atmospheric turbulence can be experimentally simulated in a controlled fashion and scaled down to distances easily accessible in a laboratory setting. This procedure is then used to simulate a 1 km long free-Space Communication link in which information is encoded in orbital angular momentum spatial modes. We also demonstrate that standard adaptive optics methods can be used to mitigate many of the effects of thick atmospheric turbulence.
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free Space Communication through turbulence a comparison of plane wave and orbital angular momentum encodings
Journal of Modern Optics, 2014Co-Authors: Mohammad Mirhosseini, Brandon Rodenburg, Mehul Malik, Robert W BoydAbstract:AbstractFree-Space Communication allows one to use spatial mode encoding, which is susceptible to the effects of diffraction and turbulence. Here, we discuss the optimum Communication modes of a system while taking such effects into account. We construct a free-Space Communication system that encodes information onto the plane-wave (PW) modes of light. We study the performance of this system in the presence of atmospheric turbulence, and compare it with previous results for a system employing orbital-angular-momentum (OAM) encoding. We are able to show that the PW basis is the preferred basis set for Communication through atmospheric turbulence for a system with a large Fresnel number product. This study has important implications for high-dimensional quantum key distribution systems.
Jeffrey D Wilson - One of the best experts on this subject based on the ideXlab platform.
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advances in Space traveling wave tubes for nasa missions
Proceedings of the IEEE, 2007Co-Authors: Jeffrey D Wilson, Edwin G Wintucky, K R Vaden, Dale A Force, I L Krainsky, Rainee N Simons, Neal R Robbins, W L Menninger, D R Dibb, David E LewisAbstract:Significant advances in the performance and reliability of traveling-wave tubes (TWTs) utilized in amplifying Space Communication signals for NASA missions have been achieved over the last three decades through collaborative efforts between NASA and primarily L-3 Communications Electron Technologies, Inc. (L-3 ETI). This paper summarizes some of the key milestones during this period and includes development of TWTs for the Communications Technology Satellite, Cassini, and Lunar Reconnaissance Orbiter missions. Technical advances in computer modeling, design techniques, materials, and fabrication have enabled power efficiency to increase by almost 40% and the output power/mass figure-of-merit to increase by an order of magnitude during this period.
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advances in Space traveling wave tubes for nasa missions used for amplifying Space Communications signals these tubes continue to efficiently and reliably deliver high power and to outperform solid state components
2007Co-Authors: Jeffrey D Wilson, Edwin G Wintucky, K R Vaden, Dale A Force, I L Krainsky, Rainee N Simons, Neal R Robbins, W L Menninger, D R Dibb, David E LewisAbstract:Significant advances in the performance and reliability of traveling-wave tubes (TWTs) utilized in amplifying Space Communication signals for NASA missions have been achieved over the last three decades through collaborative efforts between NASA and primarily L-3 Communications Electron Technologies, Inc. (L-3 ETI). This paper summarizes some of the key milestones during this period and includes development of TWTs for the Communications Technology Satellite, Cassini, and Lunar Reconnaissance Orbiter missions. Technical advances in computer modeling, design techniques, materials, and fabrication have enabled power efficiency to increase by almost 40% and the output power/mass figure-of- merit to increase by an order of magnitude during this period.
Kanglian Zhao - One of the best experts on this subject based on the ideXlab platform.
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bundle protocol for Space Communication networks in presence of intermittent link connectivity
Global Communications Conference, 2018Co-Authors: Ruhai Wang, Siwei Peng, Alaa Sabbagh, Bin Cao, Kanglian Zhao, Guannan YangAbstract:Space Communications are characterized by link intermittent connectivity and long link propagation delay. The use of bundle protocol (BP) in Space Communications has been in debate. An analytical understanding of its performance for reliable data delivery in the presence of link intermittent connectivity, especially with a lengthy link disruption, is quickly needed. In this paper, analytical models are built to estimate the number of transmission rounds (or efforts) caused by the link disruption and the resulting delay in bundle delivery of BP for applications in Space Communication networks. The models are validated by conducting bundle delivery experiments using a testbed.
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analytical framework for effect of link disruption on bundle protocol in deep Space Communications
IEEE Journal on Selected Areas in Communications, 2018Co-Authors: Alaa Sabbagh, Ruhai Wang, Scott Burleigh, Kanglian ZhaoAbstract:Delay/disruption tolerant networking (DTN) was proposed for reliable data transfer despite frequent link disruptions and long propagation delay that are typical of the deep-Space Communication environment. DTN Communications rely heavily on its core bundle protocol (BP) for reliable data delivery. To date, little work has been seen in theoretical analysis of the performance of BP in deep-Space Communications. In particular, an analytical understanding of the performance of BP for reliable data delivery in a deep-Space Communication environment in the presence of link disruptions is quickly needed. In this paper, we present a study of the effect of link disruption on transmission performance of BP, in both analytical and experimental manners, in a deep-Space Communications system characterized by link disruptions accompanied by an extremely long propagation delay and lossy data links. For the first time, an analytical framework is built to estimate the effect of link disruption on the total bundle delivery time of BP depending on its starting time with respect to bundle delivery. The analytical models are validated by running experiments using a test bed.
Brandon Rodenburg - One of the best experts on this subject based on the ideXlab platform.
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simulating thick atmospheric turbulence in the lab with application to orbital angular momentum Communication
New Journal of Physics, 2014Co-Authors: Brandon Rodenburg, Mohammad Mirhosseini, Mehul Malik, Omar S Maganaloaiza, Michael Yanakas, Laura Maher, Nicholas K Steinhoff, Glenn A Tyler, Robert W BoydAbstract:We describe a procedure by which a long () optical path through atmospheric turbulence can be experimentally simulated in a controlled fashion and scaled down to distances easily accessible in a laboratory setting. This procedure is then used to simulate a 1 km long free-Space Communication link in which information is encoded in orbital angular momentum spatial modes. We also demonstrate that standard adaptive optics methods can be used to mitigate many of the effects of thick atmospheric turbulence.
-
free Space Communication through turbulence a comparison of plane wave and orbital angular momentum encodings
Journal of Modern Optics, 2014Co-Authors: Mohammad Mirhosseini, Brandon Rodenburg, Mehul Malik, Robert W BoydAbstract:AbstractFree-Space Communication allows one to use spatial mode encoding, which is susceptible to the effects of diffraction and turbulence. Here, we discuss the optimum Communication modes of a system while taking such effects into account. We construct a free-Space Communication system that encodes information onto the plane-wave (PW) modes of light. We study the performance of this system in the presence of atmospheric turbulence, and compare it with previous results for a system employing orbital-angular-momentum (OAM) encoding. We are able to show that the PW basis is the preferred basis set for Communication through atmospheric turbulence for a system with a large Fresnel number product. This study has important implications for high-dimensional quantum key distribution systems.
