Results 201 to 210 of about 5,383 (243)
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HF Radar and Auroral Absorption
Radio Science, 1970A description is given of a method, based on riometer observations, for the calculation of auroral absorption of HF radio waves propagating over high‐latitude paths. Emphasis is on HF radar, but the method is appropriate for use in predicting circuit performance of high‐latitude HF communications.
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1970
Abstract : Aircraft, ship, and clutter echoes have been studied using surface- wave propagation on the Chesapeake Bay. These studies show that coherent pulse doppler methods can be used for surface target detection. Required radar features for several applications can be estimated.
Frank E. Boyd +3 more
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Abstract : Aircraft, ship, and clutter echoes have been studied using surface- wave propagation on the Chesapeake Bay. These studies show that coherent pulse doppler methods can be used for surface target detection. Required radar features for several applications can be estimated.
Frank E. Boyd +3 more
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1985
The development of a 26MHz pulsed Doppler radar system for remote sensing of ocean surface conditions is described. This radar obtains Doppler spectra of echoes from ocean waves within the range 10-40 km from the shore. From these Doppler spectra it is possible to estimate oceanographic parameters such as sea state, wind speed, wind direction, radial ...
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The development of a 26MHz pulsed Doppler radar system for remote sensing of ocean surface conditions is described. This radar obtains Doppler spectra of echoes from ocean waves within the range 10-40 km from the shore. From these Doppler spectra it is possible to estimate oceanographic parameters such as sea state, wind speed, wind direction, radial ...
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Behavioral model of ionospheric effects in HF radars
2017 11th European Conference on Antennas and Propagation (EUCAP), 2017The sky wave and the surface wave radars can be impacted by the instabilities of the ionosphere while they perform continuous surveillance of very large and far-off areas. When long-term integration is performed, those instabilities are leading to an increased false alarm rate. This is the typical case when detecting slow targets such as vessels.
Abi Akl, Marie José +3 more
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2011 IEEE/OES 10th Current, Waves and Turbulence Measurements (CWTM), 2011
This paper briefly reviews the theory behind wave measurement with HF radar. Data from a number of different deployments with different radars, at different frequencies, in different oceanographic conditions are used to demonstrate the wave mapping capability and to illustrate some of the problems that have arisen and solutions that have been ...
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This paper briefly reviews the theory behind wave measurement with HF radar. Data from a number of different deployments with different radars, at different frequencies, in different oceanographic conditions are used to demonstrate the wave mapping capability and to illustrate some of the problems that have arisen and solutions that have been ...
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Calibration of HF radar systems with ships of opportunity
IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477), 2004This paper addresses the application of ships of opportunity to determine the proper phase corrections for HF ground-wave phased array radar systems. Such HF radar systems are being used more and more extensively for measurements of coastal ocean surface currents.
Daniel M. Fernandez +2 more
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Target Detection Using HF Radar Data
OCEANS 2007 - Europe, 2007High frequency (HF) radar systems have a potential to detect targets which are located beyond the optical horizon on the sea surface. Unfortunately sea clutter may be strong enough to prevent such detection. In this work we present results of applying space-time adaptive processing (STAP) to this problem.
Gorski, Tomasz +5 more
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7th International Conference on High Frequency Radio Systems and Techniques, 1997
HF radar groups working within separate organisations are likely to use different versions of the HF radar equation. When it is necessary to collaborate, or otherwise share know-how, there are fresh opportunities for misunderstanding. In this paper some alternative definitions of transmission loss, antenna gain and target backscattering cross-section ...
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HF radar groups working within separate organisations are likely to use different versions of the HF radar equation. When it is necessary to collaborate, or otherwise share know-how, there are fresh opportunities for misunderstanding. In this paper some alternative definitions of transmission loss, antenna gain and target backscattering cross-section ...
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1970
Abstract : Interference to communication reception near an HF radar is dependent on many factors. It is shown that the most important of these that can be controlled is the pulse shape of the radar. Under optimum conditions, acceptable reception should be possible with frequency separation as little as 21 kHz from the proposed radar.
Burton N. Navid, Frank E. Boyd
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Abstract : Interference to communication reception near an HF radar is dependent on many factors. It is shown that the most important of these that can be controlled is the pulse shape of the radar. Under optimum conditions, acceptable reception should be possible with frequency separation as little as 21 kHz from the proposed radar.
Burton N. Navid, Frank E. Boyd
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The availability and accuracy of HF radar wave measurements
IEEE International Geoscience and Remote Sensing Symposium, 2003The possibility of measuring the ocean wave directional spectrum in real time at up to 350 locations every 10 minutes was demonstrated in the EuroROSE experiments at Fedje, Norway and Gijon, Spain in 2000. These experiments used the WERA HF radar which, at the operating frequency used, had a maximum range for wave measurements of about 20 km. Trials of
Lucy R. Wyatt, J. Jim Green
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