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The Impact of the Solar Cycle on Over-the Horizon Radar Systems

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Skywave Over-the-horizon Backscatter radar system OTH-B RS depend on ionospheric propagation conditions. These change with many different cycles the diurnal cycle, the seasonal cycle and the solar cycle and with the geographic location and design of the system. Testing the radars under conditions that represent the range of possible variations is difficult. An operational test of a half year or less, can obtain representative data for all but the solar cycle. Missing geographic ionospheric test conditions can be obtained by using data gathered in other locations and by using historical data. Testing system performance over the solar cycle can be accomplished by modeling and simulation. Several models have been developed to accomplish this task. The drawback to this approach is that modeling requires forecasts for the next solar cycle which the scientific community has great difficulty providing. This paper reviews the impact of solar cycle ionospheric changes have on OTH-B RS that operate in the mid-latitude ionosphere, and view the polar and the equatorial ionosphere. These effects are related to the solar cycle changes in solar flux and geomagnetic conditions. The lack of success of the solar-terrestrial physics community in forecasting the next solar cycle and the accompanying geomagnetic disturbances is considered. Finally, an approach to circumvent the need for a forecast of the solar flux magnitude and timing in OTH-B RS performance modeling is suggested.

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  • Atmospheric Physics
  • Active and Passive Radar Detection and Equipment
  • Radiofrequency Wave Propagation

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