Infrasound from the 2009 and 2017 DPRK rocket launches

Abstract

Summary Supersonic rockets generate low-frequency acoustic waves, that is, infrasound, during the launch and re-entry. Infrasound is routinely observed at infrasound arrays from the International Monitoring System, in place for the verification of the Comprehensive Nuclear-Test-Ban Treaty. Association and source identification are key elements of the verification system. The moving nature of a rocket is a defining criterion in order to distinguish it from an isolated explosion. Here, it is shown how infrasound recordings can be associated, which leads to identification of the rocket. Propagation modelling is included to further constrain the source identification. Four rocket launches by the Democratic People's Republic of Korea in 2009 and 2017 are analysed in which multiple arrays detected the infrasound. Source identification in this region is important for verification purposes. It is concluded that with a passive monitoring technique such as infrasound, characteristics can be remotely obtained on sources of interest, that is, infrasonic intelligence, over 4500+ km.

Evidence for Short Temporal Atmospheric Variations Observed by Infrasonic Signals: 1. The Troposphere

“…Therefore, the timescales at which changes in the atmosphere affect infrasound propagation are essential; specifically, when infrasound is used to detect, locate, and study a particular event (Arrowsmith et al., 2021). Then, propagation models are often used to explain the observations by simulating infrasound propagation through realistic atmospheric conditions, that is, temperature and winds (Applbaum et al., 2020; Assink et al., 2016, 2018; Evers et al., 2018; Fee et al., 2013; Shani‐Kadmiel et al., 2018, 2021). The atmospheric conditions are retrieved from weather prediction models or atmospheric reanalysis models operated by (but not only) the European Centre for Medium‐Range Weather Forecasts (ECMWF), North American Mesoscale Model (NAM), and NASA's Global Modeling and Assimilation Office (NASA‐GMAO).…”

Numerical Simulation of the Atmospheric Signature of Artificial and Natural Seismic Events

“…Atmospheric infrasounds originate from various processes (Le Pichon et al, , section 6.2) such as explosions (Donn & Shaw, ; Posey & Pierce, ; Reed, ), object launches/reentries (Cotten et al, ; Evers et al, ; Garcés et al, ; ReVelle, ; Yamamoto et al, ), or the mechanical coupling between the atmosphere and the solid planet (Garcia et al, ; Le Pichon & Cansi, ; Lognonné & Johnson, ; Lognonnė et al, ; Mutschlecner & Whitaker, ; Young & Greene, ). Each process generates an infrasonic signal with a specific signature in terms of waveform and arrival time (Campus & Christie, ) that could help to characterize sources and underground properties.…”

Natural and Anthropogenic Sources of Seismic, Hydroacoustic, and Infrasonic Waves: Waveforms and Spectral Characteristics (and Their Applicability for Sensor Calibration)

“…Scientific and military rocket launches and re-entries generate infrasound signals that have been detected since more than 50 years (e.g. Kaschak et al 1970 ; Evers et al 2018 ; Pilger et al 2021a ). Publications by Donn et al ( 1968 ), Kaschak et al ( 1970 ), and Balachandran and Donn ( 1971 ) analysed infrasound signals associated with the rocket launches of the early manned spaceflight programme (Saturn V, Apollo).…”

“…Publications by Donn et al ( 1968 ), Kaschak et al ( 1970 ), and Balachandran and Donn ( 1971 ) analysed infrasound signals associated with the rocket launches of the early manned spaceflight programme (Saturn V, Apollo). Olson ( 2012 ) gives an overview of the infrasound signatures of a variety of rockets ranging from small sounding to larger spaceflight rockets, Evers et al ( 2018 ) analyse the infrasound from four rocket launches for military purposes by the Democratic People’s Republic of Korea in 2009 and 2017, and Pilger et al ( 2021a ) analysed the infrasound signatures of 1001 rocket launches for space missions between 2009 and mid-2020 on infrasound stations of the IMS. Rocket launches represent well-defined ground-truth events, as usually their launch time as well as the trajectory are precisely known (e.g.…”