@TechReport{	  it:2013-018,
  author	= {Martin Almquist and Ilkka Karasalo and Ken Mattsson},
  title		= {Atmospheric Sound Propagation over Large-Scale Irregular
		  Terrain},
  institution	= {Department of Information Technology, Uppsala University},
  department	= {Division of Scientific Computing},
  year		= {2013},
  number	= {2013-018},
  month		= sep,
  abstract	= {A benchmark problem on atmospheric sound propagation over
		  irregular terrain has been solved using a stable
		  fourth-order accurate finite difference approximation of a
		  high-fidelity acoustic model. A comparison with the
		  parabolic equation method and ray tracing methods is made.
		  The results show that ray tracing methods can potentially
		  be unreliable in the presence of irregular terrain.}
}