The Experts below are selected from a list of 5730 Experts worldwide ranked by ideXlab platform
P.a. Parker - One of the best experts on this subject based on the ideXlab platform.
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ubiquitous mimo multifunction digital array Radar and the role of time energy management in Radar
2004Co-Authors: Daniel J. Rabideau, P.a. ParkerAbstract:Abstract : Future navy surface Radars will need large Power-Aperture-Gain (PAG) products so as to perform challenging Air and Missile Defense functions. Oftentimes, these Radars will operate in littoral regions, where their large PAG products will cause strong clutter returns. Unfortunately, Radar Equipment specifications can become stressed by the need to detect small targets in such strong clutter. Stressing hardware specifications include dynamic range, phase noise, system stability, isolation and spurs. Moreover, the additional desire for Low Probability of Intercept (LPI) Radar operation will also influence Radar hardware design. Hence, as Radar PAG increases, it may become increasingly difficult to design conventional Radar Equipment to operate as desired in littoral regions. To partially address these issues, some future Radar phased arrays (sometimes called "digital array Radars") will employ high degrees of aperture digitization. Typically, this digitization is performed near each of the receive elements in the array, enabling faster search rates, increased dynamic range, and improved adaptive beamforming performance. However, while such arrays offer many benefits, they still operate much like Their predecessors, i.e., They look in one narrow sector at a time, and perform a single function at any given instant. This report describes alternative approaches to operating phased array Radars, especially digital arrays. These approaches involve transmit-array time-energy management; together, these alternative approaches are shown to ease the stressing hardware requirements described above. Time-energy managed digital arrays, for example, can be used to generate both highly focused transmit beams (e.g., for track) and broad transmit illumination (e.g., for search). Broad transmit illumination provides broad angular coverage, analogous to so-called "ubiquitous" Radars (i.e., Radars that "look everywhere, all the time").
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ubiquitous mimo multifunction digital array Radar
Asilomar Conference on Signals Systems and Computers, 2003Co-Authors: Daniel J. Rabideau, P.a. ParkerAbstract:Radar Equipment specifications are often driven by the need to detect small targets in clutter. Relevant specifications include dynamic range, phase noise, system stability, isolation and spurs. Furthermore, the desire for low probability of intercept Radar operation also influences the Radar hardware design. This paper describes how digital array Radars can be used to manage Radar time and energy, thereby simplifying Radar Equipment design. Digital arrays enable both highly focused transmit beams (e.g., for track) and broad transmit illumination (e.g., for search). Regarding the latter, multi-input multi-output (MIMO) techniques, which allow wide angular coverage, are described.
Daniel J. Rabideau - One of the best experts on this subject based on the ideXlab platform.
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ubiquitous mimo multifunction digital array Radar and the role of time energy management in Radar
2004Co-Authors: Daniel J. Rabideau, P.a. ParkerAbstract:Abstract : Future navy surface Radars will need large Power-Aperture-Gain (PAG) products so as to perform challenging Air and Missile Defense functions. Oftentimes, these Radars will operate in littoral regions, where their large PAG products will cause strong clutter returns. Unfortunately, Radar Equipment specifications can become stressed by the need to detect small targets in such strong clutter. Stressing hardware specifications include dynamic range, phase noise, system stability, isolation and spurs. Moreover, the additional desire for Low Probability of Intercept (LPI) Radar operation will also influence Radar hardware design. Hence, as Radar PAG increases, it may become increasingly difficult to design conventional Radar Equipment to operate as desired in littoral regions. To partially address these issues, some future Radar phased arrays (sometimes called "digital array Radars") will employ high degrees of aperture digitization. Typically, this digitization is performed near each of the receive elements in the array, enabling faster search rates, increased dynamic range, and improved adaptive beamforming performance. However, while such arrays offer many benefits, they still operate much like Their predecessors, i.e., They look in one narrow sector at a time, and perform a single function at any given instant. This report describes alternative approaches to operating phased array Radars, especially digital arrays. These approaches involve transmit-array time-energy management; together, these alternative approaches are shown to ease the stressing hardware requirements described above. Time-energy managed digital arrays, for example, can be used to generate both highly focused transmit beams (e.g., for track) and broad transmit illumination (e.g., for search). Broad transmit illumination provides broad angular coverage, analogous to so-called "ubiquitous" Radars (i.e., Radars that "look everywhere, all the time").
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ubiquitous mimo multifunction digital array Radar
Asilomar Conference on Signals Systems and Computers, 2003Co-Authors: Daniel J. Rabideau, P.a. ParkerAbstract:Radar Equipment specifications are often driven by the need to detect small targets in clutter. Relevant specifications include dynamic range, phase noise, system stability, isolation and spurs. Furthermore, the desire for low probability of intercept Radar operation also influences the Radar hardware design. This paper describes how digital array Radars can be used to manage Radar time and energy, thereby simplifying Radar Equipment design. Digital arrays enable both highly focused transmit beams (e.g., for track) and broad transmit illumination (e.g., for search). Regarding the latter, multi-input multi-output (MIMO) techniques, which allow wide angular coverage, are described.
Ted Bapty - One of the best experts on this subject based on the ideXlab platform.
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self adaptive software for signal processing
Communications of The ACM, 1998Co-Authors: Janos Sztipanovits, Gabor Karsai, Ted BaptyAbstract:Digital signal processing (DSP) systems are widely used in communication, medical, sonar, Radar, Equipment health monitoring and many other applications. Frequently, the signal processing system has to meet real-time requirements and provide very large throughput. For example, modern automatic target recognition systems operate with a processing throughput in excess of 10 Gflop per second. In real-time vibration analysis used for turbine engine testing [1], the aggregate sustained computation rate is also in the Gflop range. The high performance requires the use of computing platforms that include the combination of dedicated hardware processors, and general-purpose computers forming a hybrid, parallel/distributed configuration. Complexity, heterogeneity of the computing environment, and real-time operation make the software development for digital signal processing difficult and expensive.
Janos Sztipanovits - One of the best experts on this subject based on the ideXlab platform.
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self adaptive software for signal processing
Communications of The ACM, 1998Co-Authors: Janos Sztipanovits, Gabor Karsai, Ted BaptyAbstract:Digital signal processing (DSP) systems are widely used in communication, medical, sonar, Radar, Equipment health monitoring and many other applications. Frequently, the signal processing system has to meet real-time requirements and provide very large throughput. For example, modern automatic target recognition systems operate with a processing throughput in excess of 10 Gflop per second. In real-time vibration analysis used for turbine engine testing [1], the aggregate sustained computation rate is also in the Gflop range. The high performance requires the use of computing platforms that include the combination of dedicated hardware processors, and general-purpose computers forming a hybrid, parallel/distributed configuration. Complexity, heterogeneity of the computing environment, and real-time operation make the software development for digital signal processing difficult and expensive.
Maja Peraica - One of the best experts on this subject based on the ideXlab platform.
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assessment of cytogenetic damage and oxidative stress in personnel occupationally exposed to the pulsed microwave radiation of marine Radar Equipment
International Journal of Hygiene and Environmental Health, 2011Co-Authors: Vera Garajvrhovac, Goran Gajski, Senijo Pažanin, Antonio Sarolic, Anamarija Domijan, Dubravka Flajs, Maja PeraicaAbstract:Due to increased usage of microwave radiation, there are concerns of its adverse effect in today's society. Keeping this in view, study was aimed at workers occupationally exposed to pulsed microwave radiation, originating from marine Radars. Electromagnetic field strength was measured at assigned marine Radar frequencies (3 GHz, 5.5 GHz and 9.4 GHz) and corresponding specific absorption rate values were determined. Parameters of the comet assay and micronucleus test were studied both in the exposed workers and in corresponding unexposed subjects. Differences between mean tail intensity (0.67 vs. 1.22) and moment (0.08 vs. 0.16) as comet assay parameters and micronucleus test parameters (micronuclei, nucleoplasmic bridges and nuclear buds) were statistically significant between the two examined groups, suggesting that cytogenetic alterations occurred after microwave exposure. Concentrations of glutathione and malondialdehyde were measured spectrophotometrically and using high performance liquid chromatography. The glutathione concentration in exposed group was significantly lower than in controls (1.24 vs. 0.53) whereas the concentration of malondialdehyde was significantly higher (1.74 vs. 3.17), indicating oxidative stress. Results suggests that pulsed microwaves from working environment can be the cause of genetic and cell alterations and that oxidative stress can be one of the possible mechanisms of DNA and cell damage.
