Three‐dimensional radar observation of a submillimeter meteoroid fragmentation
Three‐dimensional radar observation of a submillimeter meteoroid fragmentation
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亚毫米流星体碎片的三维雷达观测
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
David D. Meisel
中科院分区：
文献类型：
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作者：
J. Kero;C. Szasz;A. Pellinen‐Wannberg;G. Wannberg;A. Westman;David D. Meisel
我们提出并讨论了用三静态930mhz EISCAT超高频雷达系统观测到的两个脉动流星事件的例子。其中一个提供了第一个强有力的观测证据，表明亚毫米大小的流星体分裂成两个不同的碎片。在三个接收机的时间分布中，接收功率有规律地波动，但波动频率不同。这些脉动被解释为来自两个不同散射中心的干扰，并利用三个检测到的脉动率来计算碎片的差分速度。这一结果与两个截面积比不相等的碎片的干涉是一致的，它们由于沿母流星体轨道的不同减速而分离。另一个流星事件是流星体经历准连续解体的一个例子。这表现为在所有三个接收器上同时出现脉动。两种观测结果表明，头部回波目标的尺寸上限为32 cm雷达波长的一半。
We present and discuss two examples of pulsating meteor events observed with the tristatic 930 MHz EISCAT UHF radar system. One of them provides the first strong observational evidence of a submillimeter‐sized meteoroid breaking apart into two distinct fragments. The received power fluctuates regularly in the time profiles of all three receivers, but the fluctuation frequencies are different. The pulsations are interpreted as being due to interference from two distinct scattering centers and the three detected pulsation rates are utilized to calculate the differential velocity of the fragments. The result is consistent with interference from two fragments of unequal cross‐sectional area over mass ratio, separating from each other due to different deceleration along the trajectory of their parent meteoroid. The other meteor event is an example of a meteoroid undergoing quasi‐continuous disintegration. This manifests itself as simultaneous pulsations at all three receivers. Both observations indicate a head echo target upper size limit of the order of half the 32 cm radar wavelength.