MB-System Unix Manual Page: mb7k2ss

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    mb7k2ss
    Section:  MB-System 5.0  (1)
    Updated:  13 September 2010
    Index

    NAME

    mb7k2ss - extracts sidescan sonar
    data from Reson 7k format data, bins and lays the sidescan
    onto the seafloor, and outputs files in the MBF_MBLDEOIH
    formst (MBIO format id 71).

    VERSION

    Version 5.0

    SYNOPSIS

    mb7k2ss [-Atype
    -Bbottompickmode/bottompickthreshold -C -Dinterpbins
    -Fformat -Ifile -Lstartline/lineroot
    -M -Ooutfile -Rroutefile
    -Ttopogridfile -Urangethreshold -X -H -V]

    DESCRIPTION

    mb7k2ss is a utility that extracts Edgetech sidescan data from
    Reson 7k format (MBIO format 88) data and outputs in the MBF_MBLDEOIH
    format (MBIO format 71). Edgetech sonar systems may include dual
    frequency sidescans and a subbottom profiler. Users may use the -A
    option to specify whether low frequency or high frequency sidescan data
    are extracted. By default, low frequency sidescan is extracted.
    MB7k2ss can operate on a single input file or on a datalist
    referencing many input files.

    The raw sidescan consists of port and starboard channels, each with
    thousands of samples ordered uniformly in time from the sonar ping.
    MB7k2ss outputs a lower resolution single sidescan swath laid
    out onto the seafloor and ordered in pixels with uniform spacing in
    acrosstrack distance. Typically the output swath will have 4001
    sidescan pixels, each representing an average of several raw samples.
    To achieve this result, the program calculates the location
    of each raw sample, and bins the samples into the output swath.
    By default, the program uses the sonar altitude and a flat bottom
    assumption to calculate the sample positions. If a topography grid
    covering the survey area is input using the -T option, then
    the sample positions will be calculated using that topography and
    the resulting sidescan will be properly located on the seafloor
    (that is, if the topography is accurate...).

    The method used to determine the sonar altitude is controlled using the
    -B option. By default, the program will use the altitude value
    recorded in the vehicle navigation records. Users may also specify use
    of nadir bathymetry from co-recorded multibeam bathymetry, or the
    altitude can be picked from the first arrival observed in the sidescan
    data itself.

    The extracted sidescan data file(s) can be organized three ways.By
    default there will be a separate output file for every input file.
    If the -O option is used to specify a single output file, then
    all of the specified sidescan data will be output to that file. If
    the -R option is used to specify a survey route file that
    includes the waypoints covered while collecting the data file(s)
    referenced by -Ifile, then the output sidescan data will
    be broken up by the sequential lines defined by the waypoints. In this
    case each output Jstar file will be named using the  line root name
    specified by -Lstartline/lineroot with a sequential line
    number starting from startline. All output files will have a
    ".mb71" suffix.

    The program mbextractsegy is available to extract subbottom profiler
    data from Reson 7k data.

    AUTHORSHIP

    David W. Caress (caress@mbari.org)

      Monterey Bay Aquarium Research Institute

    Dale N. Chayes (dale@ldeo.columbia.edu)

      Lamont-Doherty Earth Observatory

    OPTIONS

    -A

    mode

    This option sets the types of data to be extracted and output.
    If -A1 is given, then any low frequency sidescan
    in the input will be extracted to the output. If -A2
    is given, then any high frequency sidescan records are extracted.
    Default: Low frequency sidescan records are extracted.
    -B

    bottompickmode/bottompickthreshold

    This option sets the source of the sonar first arrival time used for
    laying out sidescan on the seafloor. If bottompickmode = 1,
    then mb7k2ss will use the altitude value associated with
    platform navigation. If bottompickmode = 2, then mb7k2ss
    will extract the first arrival time from multibeam bathymetry in the
    7k data stream. If bottompickmode = 3, then mb7k2ss
    will pick the first arrival time in the sidescan sonar data by looking
    for the first sample with an amplitude > bottompickthreshold times the
    maximum amplitude in the trace. The altitude used will be the average of
    the first arrival times calculated for the port and starboard channels.
    Default: fIbottompickmode = 1.
    -C

    This option causes  mb7k2ss to print out any comment records
    encountered in the input Reson 7k data.
    -D

    interpbins

    Causes interpolation over gaps in the output sidescan resulting from draping
    the sidescan on topography. The interpbins values sets the maximum
    gap size over which interpolation will be applied.
    -F

    format

    Sets the data format used if the input is read from stdin
    or from a file. If format < 0, then the input file specified
    with the -I option will actually contain a list of input swath sonar
    data files. This program only reads Reson 7k format data files (MBIO
    format 88).
    -H

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

    infile

    Sets the input file path. If format > 0 (set with the
    -f option or mbdefaults) then the swath sonar data contained in infile
    is read and processed. If format < 0, then infile
    is assumed to be 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 infile file, each
    data file should be followed by a data format identifier, e.g.:

            datafile1 88

            datafile2 88

    This program only reads Reson 7k format data files (MBIO
    format 88).
    -L

    startline/lineroot

    This option sets the starting line number and the output filename root
    used when -R is specified so that data are output according
    to planned survey lines. Default: startline = 1; lineroot = "jstar".
    -M

    This option causes mb7k2ss to omit data during turns when
    extracting into line files according to a specified set of waypoints
    (-R option). The traces will not be output until the heading is
    within 15 degrees of the next survey line's bearing.
    -O

    This option sets the output MBF_LDEOIH (MBIO format 71) format file path.
    If -O is not invoked, the output filename (or filenames if a datalist
    is being processed) will be the input swath filename with the ".s7k" or ".mb88"
    suffix replaced by a ".mb71) suffix. The record types to be extracted are set
    using the -A option.
    -R

    routefile

    This option specifies an mbgrdviz route file containing the intended
    waypoints of the survey. If routefile is specified, mb7k2ss
    will output sidescan data in files corresponding to the planned survey lines.
    The output file names will be based on lineroot and will include
    the line number starting with starline, both of which are specified
    using the -L options.  If neither -O nore -R are invoked,
    the output filename (or files if a datalist is being processed) will
    be the input swath filename with an ".mb71" suffix appended.
    -T

    topogridfile

    This option specifies a GMT grid file containing a topography model of the
    survey area. When available, mb7k2ss, uses the topography to calculate
    the position of each raw sidescan sample on the seafloor prior to binning
    the sample into the swath data. This method is considerable improvement over the
    flat bottom assumption used when topography is unavailable. The grid file
    must contain topography (positive up) rather than bathymetry (positive down).
    -U

    rangethreshold

    If the -R option is specified, mb7k2ss breaks up the
    output into files corresponding to survey lines specified in a route file.
    This option sets the threshold distance in meters used to determine when
    a waypoint along the route has been reached; the program considers the
    next waypoint reached when the range to the waypoint becomes smaller
    than rangethreshold and then ceases to decrease.
    Default: rangethreshold = 50 m.
    -V

    This option increases the verbosity of mb7k2ss, causing it
    to print out messages regarding its progress to stdout.
    -W

    swathwidth
    This option sets the output sidescan swath width in meters. By default
    mb7k2ss calculates the swath width to use all of the samples available
    in the original data.
    -X

    This option switches port and starboard sidescan channels.

    EXAMPLES

    Suppose that we have collected two Reson 7k datafiles incorporating
    multibeam sonar data, sidescan data, and subbottom profiler data, and
    that the filenames are:

            20070809_173212.s7k

            20070809_175133.s7k
    After running mb7kpreprocess on these files to fix issues and
    prepare the data for processing, we will have two additional files named:

            20070809_173212.mb88

            20070809_175133.mb88
    After editing the bathymetry in the ".mb88" files with mbedit,
    and running mbprocess to apply the edits, we will have two processed
    files that are, among other uses, suitable for sidescan extraction:

            20070809_173212p.mb88

            20070809_175133p.mb88
    If we have two datalist files, one called datalist.mb-1 referencing the ".mb88"
    files with the following contents:

            20070809_173212p.mb88 88

            20070809_175133p.mb88 88
    and another called datalistp.mb-1 referencing the first datalist with a
    $PROCESSED tag:

            $PROCESSED

            datalist.mb-1 -1
    then we can extract the Edgetech sidescan from the processed files using:

            mb7k2ss -v -A1 -B2 -I datalistp.mb-1 \

                    -M -X -R MAUV_Axial_1v4.rte -L1/Axial07SS \

                    -T AxialCalderaMBARIAllTopo.grd

    Here the -R option specifies an MBgrdviz route file that was
    followed in collecting the data. By using this option, the output sidescan
    files will be broken into lines defined by the route waypoints, and the
    output filenames will be sequentially numbered. The -T option specifies a
    topography grid that is used by mb7k2ss to lay out the sidescan on
    the seafloor. The output appears as follows:

            Program mb7k2ss

            Version $Id: mb7k2ss.1 1866 2010-09-15 05:19:29Z caress $

            MB-system Version 5.1.1beta5

            Data records to extract:

                 Low Sidescan

                 Sidescan port and starboard exchanged

            Imported 45 waypoints from route file: MAUV_Axial_1v4.rte

            Grid read:

              Dimensions: 2072 3558

              Geographic Coordinate System Name: Geographic WGS84

              Geographic Coordinate System ID:   4326

              Longitude:  229.926767 230.060367  0.000065

              Latitude:   45.866667 46.026700  0.000045

              Internal Grid Projection Mode:         0

              Internal Grid Projection ID:           epsg4326

            Data Read:

              grid_projection_mode:     0

              grid_projection_id:       epsg4326

              nodatavalue:              -10000000.000000

              nx:                       2072

              ny:                       3558

              min:                      -2302.588135

              max:                      -1382.877319

              xmin:                     229.926767

              xmax:                     230.060367

              ymin:                     45.866667

              ymax:                     46.026700

              dx:                       0.000065

              dy:                       0.000045

              data:                     71467008

            Data records read from: 20070809_173212p.mb88

                 Survey:        2330

                 File Header:   2

                 Bluefin CTD:   1152

                 Bluefin Nav:   942

                 Subbottom:     0

                 Low Sidescan:  2328

                 High Sidescan: 0

            Generating inf file for Axial07SS_0001_sslo.mb71

            Generating fnv file for Axial07SS_0001_sslo.mb71

            Data records written to: Axial07SS_0001_sslo.mb71

                 Low Sidescan:  2759

                 High Sidescan: 0

            Generating inf file for Axial07SS_0002_sslo.mb71

            Generating fnv file for Axial07SS_0002_sslo.mb71

            Data records written to: Axial07SS_0002_sslo.mb71

                 Low Sidescan:  369

                 High Sidescan: 0

            Data records read from: 20070809_175133p.mb88

                 Survey:        2367

                 File Header:   2

                 Bluefin CTD:   1158

                 Bluefin Nav:   942

                 Subbottom:     0

                 Low Sidescan:  2367

                 High Sidescan: 0

            Generating inf file for Axial07SS_0003_sslo.mb71

            Generating fnv file for Axial07SS_0003_sslo.mb71

            Total data records read:

                 Survey:        4697

                 File Header:   4

                 Bluefin CTD:   2310

                 Bluefin Nav:   1884

                 Subbottom:     0

                 Low Sidescan:  4695

                 High Sidescan: 0

             Total data records written:

                  Low Sidescan:  4160

                  High Sidescan: 0

    SEE ALSO

    mbsystem(l), mbformat(l), mbinfo(l), mb7kpreprocess(l),
    mb7k2jstar(l), mbextractsegy(l), mbbackangle(l), mbprocess(l)

    BUGS

    No doubt.

     Index

    NAME
    VERSION
    SYNOPSIS
    DESCRIPTION
    AUTHORSHIP
    OPTIONS
    EXAMPLES
    SEE ALSO
    BUGS

Last Updated: 13 September 2010

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