The Draconid meteor shower shows strong bursts of activity at irregular intervals, with nearly no activity in intervening years. Five outbursts of the Draconid meteor shower were observed with specular meteor radars in Canada and Europe between 1999 and 2018. The outbursts generally lasted between 6 and 8 h, and most were not fully visible at a single geographical site, emphasizing the need for observations at multiple longitudes for short-duration shower outbursts. There is at least a factor of two difference in the peak flux as measured on different radars; the initial trail radius effect is undercorrected for Draconid meteors, which are known to be fragile.

中文翻译：

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天龙座爆发的雷达观测

天龙座流星雨以不规则的间隔显示出强烈的活动爆发，在此期间几乎没有活动。1999 年至 2018 年期间，在加拿大和欧洲用镜面流星雷达观测到五次天龙座流星雨爆发。爆发一般持续 6 到 8 小时，并且大多数在单个地理站点上并不完全可见，强调了观测的必要性短时间阵雨爆发的多个经度。在不同雷达上测量的峰值通量至少有两倍的差异；对于已知易碎的天龙座流星，初始轨迹半径效应校正不足。