Shortwave broadcasting band spectrum occupancy and signal levels in the continental United States and Western Europe

Hagn, George H.; Stehle, Roy H.; Harnish, L. O.

doi:10.1109/11.1425

Cited by 16 publications

(3 citation statements)

References 6 publications

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“…There has been a number of studies in the past that addressed the problem of interference at HF [4][5][6][7]. In the case of the Cyprus system the extensive measurement of occupancy over the HF spectrum has been conducted systematically during the last two years of system operation on an hourly basis.…”

Section: Measurement System and Proceduresmentioning

confidence: 99%

HF interference temporal and spectral characteristics over the eastern Mediterranean

Haralambous

Vryonides

2014

2014 10th International Conference on Communications (COMM)

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In the frames of the Cyprus Ionospheric Forecasting Service (CIFS) which provides near-real time information on HF propagation conditions over the island there is a component for systematic measurement and analysis of HF spectral occupancy. The incentive for this initiative stems out of the well known fact that interference from legitimate users is one of the most common problems encountered in the use of the HF spectrum due to its long range transmission properties. With the congested nature of the HF spectrum, where users with differing requirements compete for diminishing available bandwidth within the International Telecommunications Union (ITU) frequency allocations, there is strong motivation for developing an understanding for spectrum usage characteristics. In this paper preliminary results of HF spectrum occupancy measurements over the eastern Mediterranean are presented and briefly discussed in accordance to ionospheric variability.

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Section: Measurement System and Proceduresmentioning

confidence: 99%

HF interference temporal and spectral characteristics over the eastern Mediterranean

Haralambous

Vryonides

2014

2014 10th International Conference on Communications (COMM)

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“…HF external environment noise has been an important research subject. In the 1930s, many measurements and research on HF noise were started in Europe [11][12][13][14]. However, the results are controversial due to the limitations of the equipment and the lack of standardization of measurement methods.…”

Section: Introductionmentioning

confidence: 99%

Improved Main Lobe Cancellation Method for Suppression Directional Noise in HFSWR Systems

Xiao,

Zhang,

Yang

et al. 2024

Remote Sensing

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High frequency surface wave radar (HFSWR) has been successfully developed for early warning, especially for vessel target detection. However, the system’s performance is consistently constrained by external environmental noise, particularly directional noise, which presents a new problem for HFSWR. Anisotropic directional noise has complex behavior, and its noise level is generally increased by 10 to 15 dB compared to traditional noise floor level. Suppressing varying directional noise and exploring obscured targets are challenging tasks for HFSWR. In this paper, a novel algorithm based on angle-Doppler joint multi-eigenvector synthesis, which considers the angle-Doppler map of radar echoes, is adopted to analyze the characteristics of the directional noise. Given the measured data set, we first analyze the directional noise-spatial correlation. Then, an algorithm based on sliding main lobe cancellation (SL-MLC) based on a sliding single-notch space filter (SSNSF) is proposed to block target components and get training data that contains precise directional noise information. Finally, the method is examined by measured data, and the results indicate the method has better performance for directional noise than the compared method.

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“…UMIST congestion predictions versus SRI data: -87 dBm threshold, local noon, Geinsheim, Federal Republic of Germany.pared on the basis of mean measured power (in dBW) by converting SRI's data to Gott' s calibration using SRI's groundwave antenna factor as given byHagn et al [1988]. Assuming that the…”

mentioning

confidence: 99%

HF channel occupancy and band congestion: The other‐user interference problem

Stehle¹,

Hagn²

1991

Radio Science

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Information on other‐user interference is important in predicting the performance of high frequency (HF) systems. For many systems, especially frequency‐hopping systems, other‐user interference frequently is more important than man‐made noise from incidental radiators (for example, power lines) or atmospheric noise from lightning. Occupancy of individual channels and congestion of allocated HF bands (for example, fixed and mobile, amateur) vary with type of service, frequency, time of day, season, angle of arrival, type of receiving antenna, bandwidth, threshold, geographic location, and sunspot number. This paper summarizes channel occupancy and band congestion observations made in the continental United States and Europe in 1987 with SRI International's Mobile Spectrum Monitoring Unit. The data on band congestion are compared with the empirical model developed by researchers at the University of Manchester Institute for Science and Technology (UMIST), Manchester, United Kingdom. A concept for extending the UMIST model for congestion at a point to a model for congestion within a region is described.

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Shortwave broadcasting band spectrum occupancy and signal levels in the continental United States and Western Europe

Cited by 16 publications

References 6 publications

HF interference temporal and spectral characteristics over the eastern Mediterranean

HF interference temporal and spectral characteristics over the eastern Mediterranean

Improved Main Lobe Cancellation Method for Suppression Directional Noise in HFSWR Systems

HF channel occupancy and band congestion: The other‐user interference problem

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