SNAP: SACLANTCEN Normal Mode Acoustic Propagation Model

Description

SUPERSNAP is a Normal Mode Propagation model developed at SACLANT Undersea Research Centre (now Nato Undersea Research Centre [NURC]).

The version distributed by MIT has been modified for implementation on Unix platforms by H. Schmidt. This version has been made highly compatible with OASES, both in terms of installation and graphics post-processing.

Latest SUPERSNAP Release: Version 2.1 - 13 Aug 1997

How to get the MIT SUPERSNAP Package

SUPERSNAP is linked to the OASES graphics packages using the MINDIS library or PLOTMTV. Therefore, installation of the OASES export package should be completed before attempting installation of SUPERSNAP.

SUPERSNAP distribution is available from the MIT OE Acoustics Group site in two compressed formats:

snap.tar.gz
snap.tar.Z

Download either of these two files to your root directory $HOME, and issue the command

> gunzip -c snap.tar.gz | tar xvf -

which will generate the Snap directory structure. To install, simply issue the commands

> cd Snap
> make all

The SUPERSNAP executable is by default placed in the OASES bin directory, and it is assumed that OASES is installed with the default root $HOME/oases. If your desired setup is different, change Snap/Makefile accordingly. Note that the Makefile has the same hard-/software-detecting structure as in OASES, directly supporting DEC, SUN, SGI, and PC Linux platforms.

The SUPERSNAP export package includes sample data files in the Snap/tloss and Snap/pulse directories.

The execution of SUPERSNAP is OASES-like, for example for the ASA ideal wedge benchmark:

> cd ~/Snap/tloss
> snap b100
> mplot b100

It should be noted that PLOTMTV cannot currently be applied for the SUPERSNAP line plots. The default MINDIS package does, however.

An example of generating contour plots is

> cd ~/Snap/tloss
> snap munk_tl
> cplot munk_tl

cplot uses MINDIS for generating the contour plots unless PLOTMTV raster contours is selected through the environmental variable:

> setenv CON_PACKGE mtv

SUPERSNAP is also compatible with the OASES PP pulse-postprocessor for broadband time series computation. An example of its use is

> cd ~/Snap/pulse
> snap pulse

This generates the transfer function file pulse_SD00300.trf which is directly compatible with PP.

> pp

For pp, PLOTMTV can be used for timeseries plots by setting an environmental variable:

> setenv PLP_PACKGE mtv

User Manual

F.B.Jensen, M.C.Ferla. SNAP: The SACLANTCEN Normal-Mode Acoustic Propagation Model. SACLANTCEN Memorandum SM-121, Jan. 1979. SACLANT Undersea Research Centre, La Spezia.

References

F.B. Jensen, W.A. Kuperman, M.B. Porter, and H. Schmidt. Computational Ocean Acoustics. American Institute of Physics, New York, 1994.
C.M.Ferla, M.B.Porter, F.B.Jensen. C-SNAP: Coupled SACLANTCEN normal mode propagation loss model. SACLANTCEN Memorandum SM-274, Dec. 1993. SACLANT Undersea Research Centre, La Spezia.
M.B.Porter. The KRAKEN normal mode program. SACLANTCEN Memorandum SM-245, Sep. 1991. SACLANT Undersea Research Centre, La Spezia.

Henrik Schmidt / henrik@mit.edu