MB-System Unix Manual Page: mbsvpselect

### MB-System Unix Manual Page

#

##

##

##

##

##

##

##

##

##

##

    mbsvpselect
    Section:  MB-System 5.0  (1)
    Updated:  13 March 2014
    Index

    NAME

    mbsvpselect - Mbsvpselect chooses and implements the best
    available sound speed model for each swath file in a survey

    VERSION

    Version 5.0

    SYNOPSIS

    mbsvpselect -N -V -Idatalist -Ssvplist -Pmode[/criteria[/submode]]

    [-P0, -P1, -P2/period, -P3/range, -P3/range/1]
    mbsvpselect [-C -D -Fformat -H -Ifile -Mmode -O -P -S -V -Z]

    DESCRIPTION

    Mbsvpselect chooses and implements the best available sound speed model
    for each swath file in a survey. The user provides a list of the
    available sound speed models and specifies the criteria used for
    model selection. The program uses mbset to turn on bathymetry
    recalculation by raytracing through the sound speed model selected
    for each swath file.

    Description:

    The tool aims to help users to automatically apply the sound velocity
    correction to the survey files. since most surveys involve several SVPs,
    the seletion of the appropriate SVP for each survey profile is still
    missing in MB-System.

    After finding the appropriate svp for each profile based on the choosed
    method, the results are copied to a txt file that shows each survey
    profile with the corresponding SVP. the tool also calls mbset automatically
    so no need to assign SVP to the data. it is done automatically.

    There are 5 methods for choosing the appropriate SVP for each survey
    profile. These methods are:

    1. Nearest SVP in position: the middle position of each survey profile

       is calculated and the geodesics (shortest distance on the ellipsoid)

       to all SVPs are calcualted. and the SVP with the shortest distance is

       chosen. when the middle position of the survey profile is calculated

       there is an option to check for 0 lat 0 long wrong values. if it is

       found at the starting the geodesic will be calculated to the end of

       the profile.

    2. Nearest in time: the time interveal between the starting time of

       the profile and the time of the SVP, and the SVP with  the shortest

       interval will be chosen.

    3. Nearest in position within time: a default time radius from the

       profile is set as 10 hours, and within this period the nearest SVP

       in position is chosen. if none of the SVPs are within this period the

       nearest in position will be taken despit of the period threshold. The

       period threshold can be set by the user.

    4. Nearest in time within range: similar to the previous option but

       this time a default range of 10000 meters is set and within this range

       the svp nearest in time is chosen. also this 10000 meter value could

       be set by the user.

    5. Nearest in season within range: similar to the previous option the

       selected SVP could be chosen based on the month only not on the year.

       it means within the specified range the user could chose either the svp

       nearest in time or the svp nearest in month (this could be interpreted

       as the svp that falls in the same seasonal period despite of the year

       when it was taken).

    Mbsvpselect reads the .inf file of each swath file referenced in a recursive
    datalist structure to determine the location and collection time of the
    relevant data. The ancilliary *.inf, *.fbt, and *.fnv files must be created
    first. The water sound speed models (called SVPs by convention as an acronym
    for Sound Velocity Profiles) to be used must include one of three supported
    file headers specifying the time and location of the model.

    University of Bremen SVP headers:

      MB-SVP 2011/01/08 19:30:00 -52.965437  -36.986314

      (keyword yyyy/mm/dd hh:mm:ss latitude longitude)

    MB-System SVPs as now output by mbsvplist:

      #MB-SVP 2011/01/08 19:30:00 -36.986314 -52.965437

      (keyword yyyy/mm/dd hh:mm:ss longitude latitude)

    CARIS sound velocity header format:

      Section 2013-150 23:22:18 -57:02:01 -26:02:18

      (keyword yyyy-yearDay  hh:mm:ss latitude (degree:min:sec) longitude (degree:min:sec))

    Mbsvpselect supports SVP files with single models or files with multiple models where
    new headers occur between models.

    Instructions:

    1) Set up a survey (or surveys) for MB-System processing in the usual way,

       including creating a datalist file referencing the swath data of interest

       and generating the ancilliary *.inf, *.fbt, and *.fnv files for each of

       the swath files.
    2) Create an svplist file (analagous to a datalist, but referencing the

       relevant SVP files). Each SVP file is expected to be a text file with

       depth-sound speed pairs on each line (depth in meters, sound speed in

       meters/second) excepting for a header line at the start of each discrete

       model. Any of the header formats listed above will work.

       that refers to a local svp datalist. the local datalists includes
    3) In order to turn on bathymetry recalculation by raytracing through the

       most appropriate sound speed model for each swath file, call mbsvpselect:

         mbsvpselect -N -V -Idatalist -Ssvplist [-P0, -P1, -P2/period, -P3/range, -P3/range/1]

       -N is the option to check 0 latitude 0 longitude in the survey lines.

       -V verbosity.

       -I input datalist

       -S input svp datalist

       -P the method for choosing the svp where:

           -P or -P0                 is the nearest in position

           -P1                       is the nearest in time

           -P2                       is nearest in position within time (default time period is 10 hours)

           -P2/time                  is nearest in position within specified time period (in hours)

           -P3                       is nearest in time within range   (default range is 10000 meters)

           -P3/range or -P3/range/0  is nearest in time within specified range (in meters)

           -P3/range/1                     is nearest in month (seasonal) within specified range in meter.

    AUTHORSHIP

    Ammar Aljuhe (ammaraljuhne@gmail.com)

      MARUM, University of Bremen

    Christian do Santos Ferreira (cferreira@marum.de)

      MARUM, University of Bremen

    OPTIONS

    -H

    This "help" flag cause the program to print out a description
    of its operation and then exit immediately.
    -I

    datalist

    Sets the input datalist file, where datalist
    is an ascii file containing a list of the input swath sonar
    data files to be processed and their formats.  The program will read
    the data in each one of these files.
    In the file file, each
    data file should be followed by a data format identifier, e.g.:

            datafile1 11

            datafile2 24

    This program uses the MBIO library and will operate on any swath sonar
    format supported by MBIO. A list of the swath sonar data formats
    currently supported by MBIO and their identifier values
    is given in the MBIO manual page. Default: file = "datalist.mb-1".
    -N

    Causes the program to check for SVPs with zero longitude and latitude values.
    -P

    This option sets the criteria by which mbsvpselect selects the
    sound speed model to be used for each swath file.

      -P or -P0             nearest in position

      -P1                   nearest in time

      -P2                   nearest in position within time

      -P2/time              nearest in position within specified time period

      -P3                   nearest in time within range

      -P3/range             nearest in time within specified range

      -P3/range/0           nearest in time within specified range

      -P3/range/1           nearest in month (seasonal) within specified range

    The times are specified in hours and the ranges in meters.
    The default time period is 10 hours and the default range is 10000 meters.
    -S

    svplist

    Sets the input svplist file, where svplist
    is an ascii file containing a list of the input sound speed model
    or SVP files.  The program will read
    the location and time stamp information for all of the models
    in each one of these files.
    In the svplist file, each
    SVP file should be on a separate line, e.g.:

            svpfile1

            svpfile2

    Default: file = "svplist.mb-1".
    -V

    Normally, mbsvpselect works "silently" without outputting
    anything to the stderr stream.  If the
    -V flag is given, then mblist works in a "verbose" mode and
    outputs the program version being used and all error status messages.

    EXAMPLES

    Suppose you are working in a directory called Survey_1 containing
    swath files that need to have the bathymetry recalculated by
    raytracing through water sound speed models. The local datalist
    file might contain something like:

         13349457_3934_2845.mb88 88

         13645323_3433_5543.mb88 88

         46372536_6563_4637.mb88 88

         64362825_6344_2635.mb88 88

    or, if you use absolute passwords, something like:

         /MyMac/User/Survey_1/13349457_3934_2845.mb88 88

         /MyMac/User/Survey_1/13645323_3433_5543.mb88 88

         /MyMac/User/Survey_1/46372536_6563_4637.mb88 88

         /MyMac/User/Survey_1/64362825_6344_2635.mb88 88

    By convention, this datalist will be named something
    like datalist.mb-1, where the ".mb-1" suffix indicates to
    MB-System programs that this is a datalist file. As
    documented elsewhere, datalist files can contain entries
    that reference datalists rather than single files; thus
    datalists can be recursive.

    Suppose that the water properties were variable during this
    survey, with the variability dominated by location.Further suppose
    that there are three SVP files in a separate directory with
    names such as svp1.svp, svp2.svp, and svp3.svp. Each of these files
    contains a single model derived from CTD casts at a particular
    place and time indicated in the single header line. In that directory
    one can create an svplist file named SVP_list.mb-1 with contents:

         svp1.svp

         svp2.svp

         svp3.svp
    Since mbsvpselect allows svplists to be recursive (like datalists),
    one can create a second svplist named my_svplist.mb-1in the survey
    processing directory that references the first with an entry like:

         /MyMac/User/Survey_1/SVP_folder/SVP_list.mb-1 -1

    In order to turn on bathymetry recalculation for all of the
    swath files referenced by datalist.mb-1 using the most appropriate
    of the available sound speed models, run mbsvpselect with arguments
    like:

         mbsvpselect -N -V -I datalist.mb-1 -S my_svplist.mb-1 -P2/50

    Here the -P2/50 option specifies that the sound speed model to be
    used for each file will be the closest one collected within 50 hours
    of the swath data. The bathymetry recalculation will be turned on
    using an mbset call of the form:

         mbset -Idatalist.mb-1 -PSVPFILE:/MyMac/User/Survey_1/SVP_folder/svp1.svp

    Following the mbsvpselect usage, mbprocess must be run to actually
    reprocess the swath data, including bathymetry recalculation by
    raytracing.

    SEE ALSO

    mbsystem(1), mbprocess(1), mbset(1), mbsvplist(1)

    BUGS

    The bugs are special because they are from Egypt, Germany, and Brazil.

     Index

    NAME
    VERSION
    SYNOPSIS
    DESCRIPTION
    AUTHORSHIP
    OPTIONS
    EXAMPLES
    SEE ALSO
    BUGS

Last Updated: 13 March 2014

Return to list of MB-System manual pages...

Back to MB-System Home Page...