Abstract

The subject of this study is the infrasonic signal generated by a high-speed (32 km/s), high-energy (173 kt TNT), and large-sized (9.4 m) celestial body, later called the Kamchatka meteoroid, which entered the terrestrial atmosphere and exploded on December 18, 2018. The focus of the study is the parameters of the infrasonic signal launched by the Kamchatka meteoroid. The study is based on the data on temporal dependences of pressure in the infrasonic wave collected by the I53US, I30JP, I59US, I46RU, I57US, and MAAG2 infrasonic stations included in the International Monitoring System (IMS) set up by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). The measurement data initially recorded on a relative scale were converted into absolute values. The temporal dependences of the infrasonic wave pressure were then filtered in the 1–40-s period range and were subsequently subjected to system spectral analysis that included the mutually complementary short-time Fourier transform, adaptive Fourier transform, and the wavelet transform with the Morlet wavelet as the basis function. As a result, it was found that the infrasonic signal amplitude exhibits quite a rapid decrease with distance between an infrasonic station and the meteoroid’s explosion site. The time delay of the infrasonic signal shows an increase with distance between the celestial body explosion and the site of signal detection. The signal celerity exhibits a dependence on the distance and the path orientation; it is estimated to be in the range of 269–308 m/s. The infrasonic signal duration shows virtually no dependence on the distance from the detonation point to an infrasonic station. The infrasonic signal spectra have a wide bandwidth with periods from ∼5 to ∼40 s. At the same time, the greatest energy falls within the isolated periods of 12–15 s and 28–33 s. The scatter diagrams and regressions for the infrasound main parameters were plotted. The celestial body’s kinetic energy (179 kt TNT) and acoustic efficiency (∼4%) were estimated from the prevailing infrasonic period.

中文翻译：

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堪察加陨石产生的次声信号的参数

摘要

这项研究的主题是由高速（32 km / s），高能（173 kt TNT）和大型（9.4 m）天体（后来称为堪察加流星体）产生的次声信号，在2018年12月18日发生爆炸。研究的重点是堪察加流星体发射的次声信号的参数。这项研究基于I53US，I30JP，I59US，I46RU，I57US和MAAG2次声台站收集的次声波压力随时间的数据，该系统由综合核试验建立，并已包含在国际监测系统（IMS）中-禁毒条约组织（CTBTO）。最初以相对刻度记录的测量数据被转换为绝对值。然后在1–40 s的周期范围内过滤次声波压力的时间相关性，然后进行系统频谱分析，包括相互互补的短时傅立叶变换，自适应傅立叶变换和Morlet的小波变换小波为基础函数。结果，发现次声信号幅度随次声站与流星体爆炸位置之间距离的增加而迅速减小。次声信号的时间延迟显示，天体爆炸与信号检测位置之间的距离会增加。信号速度取决于距离和路径方向。估计范围为269-308 m / s。次声信号的持续时间实际上显示不依赖于从爆震点到次声站的距离。次声信号频谱具有很宽的带宽，周期约为5到40 s。同时，最大的能量落在12-15 s和28-33 s的隔离时间内。绘制了次声主要参数的散点图和回归曲线。天体的动能（179 kt TNT）和声效率（〜4％）是根据次声周期估算得出的。