\documentclass[10pt]{article}

\usepackage{fullpage}
\usepackage{setspace}
\usepackage{parskip}
\usepackage{titlesec}
\usepackage[section]{placeins}
\usepackage{xcolor}
\usepackage{breakcites}
\usepackage{lineno}
\usepackage{hyphenat}





\PassOptionsToPackage{hyphens}{url}
\usepackage[colorlinks = true,
            linkcolor = blue,
            urlcolor  = blue,
            citecolor = blue,
            anchorcolor = blue]{hyperref}
\usepackage{etoolbox}
\makeatletter
\patchcmd\@combinedblfloats{\box\@outputbox}{\unvbox\@outputbox}{}{%
  \errmessage{\noexpand\@combinedblfloats could not be patched}%
}%
\makeatother


\usepackage{natbib}




\renewenvironment{abstract}
  {{\bfseries\noindent{\abstractname}\par\nobreak}\footnotesize}
  {\bigskip}

\titlespacing{\section}{0pt}{*3}{*1}
\titlespacing{\subsection}{0pt}{*2}{*0.5}
\titlespacing{\subsubsection}{0pt}{*1.5}{0pt}


\usepackage{authblk}


\usepackage{graphicx}
\usepackage[space]{grffile}
\usepackage{latexsym}
\usepackage{textcomp}
\usepackage{longtable}
\usepackage{tabulary}
\usepackage{booktabs,array,multirow}
\usepackage{amsfonts,amsmath,amssymb}
\providecommand\citet{\cite}
\providecommand\citep{\cite}
\providecommand\citealt{\cite}
% You can conditionalize code for latexml or normal latex using this.
\newif\iflatexml\latexmlfalse
\providecommand{\tightlist}{\setlength{\itemsep}{0pt}\setlength{\parskip}{0pt}}%

\AtBeginDocument{\DeclareGraphicsExtensions{.pdf,.PDF,.eps,.EPS,.png,.PNG,.tif,.TIF,.jpg,.JPG,.jpeg,.JPEG}}

\usepackage[utf8]{inputenc}
\usepackage[english]{babel}



\usepackage{float}








\begin{document}

\title{Strong Amplification of ELF/VLF Signals in Space Using Neutral Gas
Injections from a Satellite Rocket Engine}



\author[1]{Paul Bernhardt}%
\author[2]{William Bougas}%
\author[2]{Michael Griffin}%
\author[3]{Chris Watson}%
\author[4]{Richard B. Langley}%
\author[5]{Andrew David Howarth}%
\author[6]{H. Gordon James}%
\author[1]{Carl Siefring}%
\author[7]{Gareth William Perry}%
\author[8]{J.D. Huba}%
\author[9]{Robert Christian Moore}%
\author[10]{Morris B. Cohen}%
\author[11]{Mark Golkowski}%
\affil[1]{Naval Research Laboratory}%
\affil[2]{MIT Lincoln Laboratory}%
\affil[3]{University Corporation for Atmospheric Research}%
\affil[4]{University of New Brunswick}%
\affil[5]{University of Calgary}%
\affil[6]{Residence}%
\affil[7]{New Jersey Institute of Technology}%
\affil[8]{Syntek Technologies}%
\affil[9]{University of Florida}%
\affil[10]{Georgia Institute of Technology}%
\affil[11]{University of Colorado Denver}%


\vspace{-1em}



  
  \date{May 19, 2024}


\begingroup
\let\center\flushleft
\let\endcenter\endflushleft
\maketitle
\endgroup





\selectlanguage{english}
\begin{abstract}
The first demonstration of rocket exhaust driven amplification (REDA) of
whistler mode waves occurred on 26 May 2020 by transferring energy from
pickup ions in a rocket exhaust plume to EM waves. The source of
coherent VLF waves was the Navy NML Transmitter at 25.2 kHz located in
LaMoure, North Dakota. The topside ionosphere at 480 km altitude became
an amplifying medium with a 60 second firing of the Cygnus BT-4 engine.
The rocket engine injected exhaust as a neutral cloud moving
perpendicular to field lines that connected the NML transmitter to the
VLF Radio Receiver Instrument (RRI) on e-POP/SWARM-E. Charge exchange
between the ambient O\textsuperscript{+} ions and the hypersonic water
molecules in the exhaust produced H\textsubscript{2}O\textsuperscript{+}
ions in a ring-beam velocity distribution. The 25.2 kHz VLF signal from
NML was amplified by 30 dB for a period 77 seconds as observed by the
RRI. Simultaneously, preexisting coherent ELF waves at 300 Hz were
amplified by 50 dB during and after the Cygnus burn. Extremely strong
coherent emissions and quasi-periodic bursts in the 300 to 310 Hz
frequency range lasted for 200 seconds after the release. The excitation
of an ELF whistler cavity may have lasted even longer, but the orbit of
the SWARM-E/e-POP moved the RRI sensor away from the wave emission
region. The amplified 300 Hz ELF waves may have gained even more energy
by cyclotron resonance with radiation belt electrons as they were ducted
between geomagnetic-conjugate hemispheres.%
\end{abstract}%



\sloppy




\selectlanguage{english}
\FloatBarrier
\end{document}

