Abstract Mean night-time peak power, Doppler shift and Doppler width of spread Doppler clutter (SDC) received by a high frequency backscatter radar located at Alice Springs, Australia from 2000 to 2018 is presented as a function of azimuth, sunspot number, time of year and frequency. The sampled region covers 90 degrees from West to North and includes the northern and southern equatorial anomalies. SDC peak power diminished across all azimuths during the winter solstice from around May to August (local winter) coinciding with the global decrease in F layer density due to the annual non-seasonal F2 anomaly but was generally constant during the equinoxes. In contrast, SDC Doppler width and inbound Doppler shift both increased during the equinoxes and exhibited azimuthal dependence related to the eastward equatorial plasma drift. SDC peak power increased with increasing sunspot number with frequency dependence during winter but not summer. Inbound Doppler shift and Doppler width increased with increasing sunspot number during equinox but not solstice with a strong dependence on azimuth and a weak dependence on frequency.

中文翻译：

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在澳大利亚爱丽斯泉记录的 HF 扩展多普勒杂波的多普勒特征

摘要 位于澳大利亚爱丽斯泉的高频反向散射雷达从 2000 年到 2018 年接收到的扩展多普勒杂波 (SDC) 的平均夜间峰值功率、多普勒频移和多普勒宽度表示为方位角、太阳黑子数、时间的函数。年份和频率。采样区域从西到北 90 度，包括北赤道异常和南赤道异常。在 5 月至 8 月左右（当地冬季）的冬至期间，SDC 峰值功率在所有方位上都减小，这与由于年度非季节性 F2 异常导致的 F 层密度全球降低一致，但在春分点期间基本保持不变。相比之下，SDC 多普勒宽度和入站多普勒频移在春分点期间均增加，并表现出与向东赤道等离子体漂移相关的方位角依赖性。SDC 峰值功率随着太阳黑子数量的增加而增加，冬季但不是夏季频率依赖性。入站多普勒频移和多普勒宽度在春分期间随着太阳黑子数的增加而增加，但在冬至没有强烈依赖于方位角而对频率的依赖弱。