Publication: Characteristics of boomerang whistler-mode waves wmitted from the DSX spacecraft
Program
School / College / Institute
College of Engineering
KU-Authors
KU Authors
Co-Authors
Starks, M. J.
Lauben, D. S.
Albert, J. M.
Farrell, W. M.
Galkin, I. A.
Ginet, G. P.
Johnston, W. R.
Linscott, I. R.
Sanchez, J. C.
Song, P.
Publication Date
Language
Type
Embargo Status
Journal Title
Journal ISSN
Volume Title
Alternative Title
Abstract
The Air Force Research Laboratory's Demonstration and Science Experiments (DSX) spacecraft carried a high-voltage very low frequency transmitter and a sensitive broadband receiver to medium Earth orbit in 2019. During many pulsed transmission experiments, DSX detected apparent "boomerang" echoes when its emitted waves refracted in the magnetosphere and returned to the spacecraft. We simulated a series of these detected pulses using cold plasma ray tracing to characterize their likely wavelengths, indices of refraction, and initial wave normal angles. The waves were shown to remain relatively local to DSX, to be lightly damped, and to have a wide variety of wavelengths and indices of refraction, but they were all emitted with very oblique wave normal angles tightly clustered about half a degree from the Gendrin angle, which theoretical antenna models predict is preferentially excited. Our results are remarkably consistent with this prediction but are statistically biased closer to the resonance cone, possibly because of limitations in the ray tracing technique. The result is robust to perturbations of the simulation and confirms a very narrow beam of oblique radiation quite unlike the behavior of a dipole in vacuo.
Source
Publisher
Amer Geophysical Union
Subject
Astronomy, Astrophysics
Citation
Has Part
Source
Journal of Geophysical Research-Space Physics
Book Series Title
Edition
DOI
10.1029/2023JA031300