8,587 research outputs found

    Energy and Flux Measurements of Ultra-High Energy Cosmic Rays Observed During the First ANITA Flight

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    The first flight of the Antarctic Impulsive Transient Antenna (ANITA) experiment recorded 16 radio signals that were emitted by cosmic-ray induced air showers. For 14 of these events, this radiation was reflected from the ice. The dominant contribution to the radiation from the deflection of positrons and electrons in the geomagnetic field, which is beamed in the direction of motion of the air shower. This radiation is reflected from the ice and subsequently detected by the ANITA experiment at a flight altitude of 36km. In this paper, we estimate the energy of the 14 individual events and find that the mean energy of the cosmic-ray sample is 2.9 EeV. By simulating the ANITA flight, we calculate its exposure for ultra-high energy cosmic rays. We estimate for the first time the cosmic-ray flux derived only from radio observations. In addition, we find that the Monte Carlo simulation of the ANITA data set is in agreement with the total number of observed events and with the properties of those events.Comment: Added more explanation of the experimental setup and textual improvement

    Radiation Pattern Reconstruction from the Near-Field Amplitude Measurement on Two Planes Using PSO

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    The paper presents a new approach to the radiation pattern reconstruction from near-field amplitude only measurement over a two planar scanning surfaces. This new method for antenna pattern reconstruction is based on the global optimization PSO (Particle Swarm Optimization). The paper presents appropriate phaseless measurement requirements and phase retrieval algorithm together with a brief description of the particle swarm optimization method. In order to examine the methodologies developed in this paper, phaseless measurement results for two different antennas are presented and compared to results obtained by a complex measurement (amplitude and phase)

    Terasense WP03 radiation and sensor measurement lab workpackage

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    This paper explains the progress accomplished in the WP03 of the Terasense Project (TERAHERTZ TECHNOLOGY FOR ELECTROMAGNETIC SENSING APPLICATIONS) approved in the 2008 CONSOLIDERINGENIO program (project CSD2008-0068). The Radiation and Sensor Measurement Lab (RSMLab) is a laboratory based in the existing antenna measurement laboratories at UPM, UC3 and UNiOvi and the new capacities to extend the measurement range from the millimetre wave to the THz region. This laboratory is intended to be shared in more than one place and with more than one institution, in such a way that we could take advantage of other research financial sources and contributions from other institutions with interest in the same field of measurements. One important task will be the international links between the RSMLab and other European and international institutions dedicated to the antenna and sensor measurement in the same frequency range

    Over-the-air characterization of millimeter-wave integrated antenna systems

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    Multi-probe Enabled Over-the-air Calibration of Millimeter-wave Antenna Array: Concept and Experimental Validation

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    Millimeter wave (mmWave) antenna array systems with high-gain beam-steerablecapability play a key role in fulfilling the high data-rate demands of the fifth generation (5G)and beyond wireless technologies. Rigorous array calibration is essential to ensure theirradiation performance fulfills the standard requirements before massive rollout. These testswill exclusively transition to over-the-air (OTA) testing approaches with antennas included,due to the lack of antenna connectors and their compact and highly integrated designsin emerging mmWave radio systems. This has posed huge challenges on measurementand calibration of mmWave antenna arrays, due to the more demanding requirement onsystem complexity, implementation cost, measurement time, and measurement uncertainty.In this work, a multi-probe framework for phased array calibration is introduced, aimingto achieve objectives including measurement range reduction, measurement efficiencyimprovement and measurement accuracy enhancement compared with the conventionalsingle-probe method. The basic principle, capabilities, limitations, and design of multi-probe configuration are detailed for each measurement objective. Moreover, extensivemeasurement results were presented to validate the effectiveness and robustness of theproposed multi-probe based array calibration algorithms for each measu

    Over-the-air characterization of millimeter-wave integrated antenna systems

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    Detection, identification and localization of R/C electronic devices through their unintended emissions

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    The accurate and reliable detection of unintended emissions from radio receivers has a broad range of commercial and security applications. This thesis presents detection, identification, and localization methods for multiple RC electronic devices in a realistic environment. First, a Hurst parameter based detection method for super-regenerative receivers (SRR) has been used for detection. Hurst parameter based detection method exploits a self-similarity property of the SRR receiver emissions to distinguish it from background noise. Second paper presents a novel detection and localization scheme of multiple RC electronic devices called Edge-Synthetic Aperture Radar (Edge-SAR). It employs cost-effective, mobile antenna-array detectors. Two types of RC devices are considered: SRR with H parameter method and super heterodyne receivers (SHR) with peak detection method. Third paper improves detection of multiple devices by proposing a dynamic antenna-array processing method called VIVEK-MVDR-GA. It combines multi-constrained genetic algorithm (GA) and minimum variance distortion-less response (MVDR) method to increase accuracy of detection and localization of multiple devices. Finally, a 4-element array mounted on an unmanned aerial vehicle (UAV) is proposed to overcome multipath and reflection due to environmental surroundings and improve the response time in compromised scenarios. Also, a time based correlation method is proposed for array detectors to identify the line of sight (LOS) and non-line of sight (N-LOS) signals. A normalized error correlation function has been implemented to improve the estimation of angle of arrival (AOA) in the presence of strong non-line of sight (N-LOS) signals --Abstract, page iv

    Ka-band integrated focal-plane arrays for two-way satellite communication

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