HWT_3D_mm program performs calculation of three-dimensional shapes of wavefronts, timefronts 
and ray trajectories of acoustical waves in inhomogeneous moving media including ocean and
atmosphere. The code is a numerical implementation of the 'Eulerian geometrical acoustics,' 
where wavefronts rather than rays are the primary objects. Wavefronts are found as a 
finite-difference solution to a system of partial differential equations, which is 
equivalent to the eikonal equation and is a direct implementation of the intuitive 
Huygens’ wavefront construction. 

An extension for moving media by N. Zabotin, O.A. Godin and L.Ye. Zabotina (Copyright (C) 2013 
University of Colorado Boulder) of an algorithm developed by P. Sava and S. Fomel as a part 
of Madagascar open project (Copyright (C) 2007 Colorado School of Mines).

Benchmarking and applications of the 2-D version of the code are discussed in the paper 

Zabotin N. A., Godin O. A., Sava P. C., and Zabotina L. Y. Acoustic wavefront tracing in 
inhomogeneous, moving media, J. Comput. Acoust. 20 (3), Art. 125009 (2012). 
DOI: 10.1142/S0218396X12500099. 

Another paper, which discusses the 3-D version of the code, has been recently submitted to 
the Journal of Computational Acoustics.

The code may be compiled and run as a stand-alone application both under Linux and Windows.
A brief manual can be found in the beginning of the main program file HWT_3D_mm_main.c.

16 September 2013