The Kongsberg's SIS package handles the Sound Velocity profiles by its own GUI, requiring manual or external file input in the Kongsberg's ASVP ASCII format. After proper editing, the profile is thinned, the Absortion coefficient are calculated and data stored for future usage within the package. The edit phase requires that the profile is continued down to the full ocean depth of 12000m, even if water depth or used MBES was much less of that, e.g. the EM3000, 400m range , or the EM710, 3000m range systems or when operating on the continental shelf or rise. The operation was found to be somewhat error-prone, mostly when dealing with defaults that may merge data from other areas of world ocean.
The idea of producing a (semi)automated procedure for the generation of a SV profile continued down to 12000m, hence directly usable for thinning and Absorption coefficient calculations was carried on by the availability of Oceanographical statistical data in the Ocean, namely the Levitus Database ([Levitus (1982)]), and by programs that have interfaced them and made available the data, namely the mblevitus in the Open Source MBSystem package for Multibeam processing ([Caress and Chayes (2009)] and [Schmidt et al.(2004)]). mblevitus is able to create a water velocity profile which is representative of the mean annual water column for a specified 1 by 1 °region. Therefore, we firstly developped a routine to create data for a wide ocean region in a format to be used independently by other programs, without the need of having the MBSystem package installed. We have chosen to use widely used and available programming languages, like the BASH shell and Perl ([Bash (2009)],[Perl (2009)]), available in the Unix, Mac-OSX, and Windows (Cygwin or native) O.S. Environments.
The Bash routine CREATE_LEVITUS_PROFILE (6.1) creates a directory where Ascii files are produced for a certain Ocean Region. Then, the Bash routine FROM_CNV_TO_ASVP (6.2) produces the conversion of SBE's CNV file to ASVP, by calling the Perl cnv2asvp.pl routine (6.3). The routine have code translated from fortran to Perl from the UNESCO/IOC adopted Oceanographical formulae in the Woods Hole Oceanographic Institution's Package (for converting depth values to dbar and calculate Sound Velocity from salinity, temperature and pressure). The routine can be changed to fit with other CTD systems, producing different formats, as long as they are able to provide depth and Sound velocity data. The ASVP profiles can be used for input to the SIS Acquisition system or for further processing by other packages like Kongsberg's Neptune.
language=Perl