Investigating the relationship between bolide entry angle and apparent direction of infrasound signal arrivals

Fuente: arXiv
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Main Author: Silber, Elizabeth A.
Format: Preprint
Published: 2025
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author Silber, Elizabeth A.
author_facet Silber, Elizabeth A.
contents Infrasound sensing offers critical capabilities for detecting and geolocating bolide events globally. However, the observed back azimuths, directions from which infrasound signals arrive at stations, often differ from the theoretical expectations based on the bolide's peak brightness location. For objects with shallow entry angles, which traverse longer atmospheric paths, acoustic energy may be emitted from multiple points along the trajectory, leading to substantial variability in back azimuth residuals. This study investigates how the entry angle of energetic bolides affects the back azimuth deviations, independent of extrinsic factors such as atmospheric propagation, station noise, and signal processing methodologies. A theoretical framework, the Bolide Infrasound Back-Azimuth EXplorer Model (BIBEX-M), was developed to compute predicted back azimuths solely from geometric considerations. The model quantifies how these residuals vary as a function of source-to-receiver distance, revealing that bolides entering at shallow angles of 10 degrees can experience average residuals of 20 degrees, with deviations reaching up to 46 degrees at distances below 1000 km, and remaining significant even at 10,000 km. In contrast, bolides with steeper entry angles (greater than 60 degrees) show much smaller deviations, typically under 5 degrees at 1000 km and diminishing to less than 1 deg beyond 5000 km. These findings attest to the need for careful interpretation when evaluating signal detections and estimating bolide locations. This work is not only pertinent to bolides but also to other high-energy, extended-duration atmospheric phenomena such as space debris and reentry events, where similar geometric considerations can influence infrasound arrival directions.
format Preprint
id arxiv_https___arxiv_org_abs_2503_13972
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Investigating the relationship between bolide entry angle and apparent direction of infrasound signal arrivals
Silber, Elizabeth A.
Atmospheric and Oceanic Physics
Earth and Planetary Astrophysics
Instrumentation and Methods for Astrophysics
Geophysics
Infrasound sensing offers critical capabilities for detecting and geolocating bolide events globally. However, the observed back azimuths, directions from which infrasound signals arrive at stations, often differ from the theoretical expectations based on the bolide's peak brightness location. For objects with shallow entry angles, which traverse longer atmospheric paths, acoustic energy may be emitted from multiple points along the trajectory, leading to substantial variability in back azimuth residuals. This study investigates how the entry angle of energetic bolides affects the back azimuth deviations, independent of extrinsic factors such as atmospheric propagation, station noise, and signal processing methodologies. A theoretical framework, the Bolide Infrasound Back-Azimuth EXplorer Model (BIBEX-M), was developed to compute predicted back azimuths solely from geometric considerations. The model quantifies how these residuals vary as a function of source-to-receiver distance, revealing that bolides entering at shallow angles of 10 degrees can experience average residuals of 20 degrees, with deviations reaching up to 46 degrees at distances below 1000 km, and remaining significant even at 10,000 km. In contrast, bolides with steeper entry angles (greater than 60 degrees) show much smaller deviations, typically under 5 degrees at 1000 km and diminishing to less than 1 deg beyond 5000 km. These findings attest to the need for careful interpretation when evaluating signal detections and estimating bolide locations. This work is not only pertinent to bolides but also to other high-energy, extended-duration atmospheric phenomena such as space debris and reentry events, where similar geometric considerations can influence infrasound arrival directions.
title Investigating the relationship between bolide entry angle and apparent direction of infrasound signal arrivals
topic Atmospheric and Oceanic Physics
Earth and Planetary Astrophysics
Instrumentation and Methods for Astrophysics
Geophysics
url https://arxiv.org/abs/2503.13972