MB-System Unix Manual Page: mb7kpreprocess

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    mb7kpreprocess
    Section:  MB-System 5.0  (1)
    Updated:  12 November 2014
    Index

    NAME

    mb7kpreprocess - performs preprocessing of Reson 7k multibeam data
    in the 7k format (MBIO format 88).

    VERSION

    Version 5.0

    SYNOPSIS

    mb7kpreprocess [-A -B -Crollbias/pitchbias
    -Doffx/offy[/offdepth] -Fformat
    -Ifile -Kklugemode -L -Mrockfile -Ninsfile -Ooutfile
    -Psonardepthfile -PFfilterlength/filterdepth
    -Ttimelag -Wdslfile -H -V]

    DESCRIPTION

    mb7kpreprocess reads a Reson 7k (format 88) file, interpolates the
    asynchronous navigation and attitude onto the multibeam data,
    and writes a new 7k file with that information correctly embedded
    in the multibeam data. This program can also fix various problems
    with 7k data (early generations of the 6046 datalogger failed to
    to meet the data format specification exactly).

    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

    This option causes the program to output multibeam records occuring before the first
    available navigation and attitude data. Normally, these records are ignored.
    -B

    mode

    This option is only relevant to MBARI Mapping AUV data that includes Edgetech sidescan
    and subbottom profiler data with multibeam data in a Reson 7k format file, and where the
    sonars are all synchronized to ping simulataneously. If -B is specified with
    mode=1, then the multibeam time stamps will be reset to the time stamp values of
    the Edgetech data records. If -B is given with mode=2, then the Edgetech
    data time stamps will be reset to the values of the multibeam data records. Although the
    sonar computer clocks are supposed to be synchronized, this clock discipline sometimes fails.
    -C

    rollbias/pitchbias

    This option sets the roll and pitch bias of the sonar with respect to the attitude sensor
    in degrees. If specified, these parameters are applied to the sonar attitude data prior to
    the calculation of bathymetry from travel times and angles.
    -D

    offx/offz[/offdepth]

    This option sets horizontal and vertical.distance offsets between the vehicle's
    depth sensor and the multibeam receive head. If specified, these values are used
    in a lever-arm calculation to determine the sonar depth change  associated with
    vehicle pitch. The offdepth value, if specified, is a static depth offset to be
    applied to the vehicle depth data.
    -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).
    -K

    klugemode

    This option causes the program to implement one of the available
    processing "kluge" fixes. This are unusual steps required to fix
    data with particular, unusual problems. Kluge 1 forces mb7kpreprocess
    to replace the sonar depth value with values from vertical
    depth data records. Kuge 2 forces mb7kpreprocess to zero the initial
    beam alongtrack distance values.
    -L

    This option causes the program to list the timetags of bathymetry,
    sidescan, subbottom, navigation, and attitude data records.
    -M

    rockfile

    The program will read navigation and attitude from the Steve Rock navigation
    and attitude file rockfile and merge those data with the multibeam, sidescan,
    and subbtottom data in the 7k file.If a timelag model is specified using
    -Ttimelag, the time lag will be applied to the navigation and
    attitude data before merging with the sonar data. The navigation and attitude
    data from rockfile will also be embedded in asynchronous data records
    in the output 7k format data. Any pre-existing navigation data records will
    be replaced. The similar -Ninsfile and -Wdslfile options
    cause merging of data from MBARI AUV logfiles and WHOI DSL navigation files,
    respectively. The Steve Rock navigation and attitude file is a text file with
    seven space delimited columns:

            time_d longitude latitude sonardepth heading roll pitch

    where time_d is decimal seconds since the start of 1970, longitude, latitude,
    heading, roll, and pitch are in decimal degrees, and sonardepth is in meters.
    -N

    insfile

    The program will read navigation and attitude from the MBARI AUV navigation
    log file insfile and merge those data with the multibeam, sidescan,
    and subbtottom data in the 7k file. If a timelag model is specified using
    -Ttimelag, the time lag will be applied to the navigation and
    attitude data before merging with the sonar data. The navigation and attitude
    data from insfile will also be embedded in asynchronous data records
    in the output 7k format data. Any pre-existing navigation data records will
    be replaced. MBARI AUV navigation files are binary and specific to MBARI.
    -O

    outfile

    This option causes mb7kpreprocess to output all data to a single file
    specified as outfile. By default, the program creates output files for
    each input file.
    -P

    sonardepthfile

    The program will read sonar depth data from sonardepthfile and merge
    those data with the multibeam, sidescan, and subbtottom data in the 7k file.
    The sonardepthfile is a text data file containing two space delimited columns:

            time_d sonardepth

    where:

            time_d - decimal epoch seconds (since start of 1970)

            sonardepth - sonar depth in meters, positive down

    -PF

    -PFfilterlength/filterdepth
    This option specifies Gaussian tapered time domain filtering of the
    sonar depth data to be merged with the survey data, regardless of source.
    The filterlength value specifies
    the filter window length in seconds, and the filterdepth value controls
    the depths to which filtering is applied. The filtered sonar depth is used
    to depths up to twice the filterdepth value. Below that threshold, the
    value used transitions to unfiltered with an exponential taper. This filtering
    is used in two ways. First, one can apply short period smoothing of noisy
    sonar depth at all by specifying a small filterlength (e.g. 2 seconds)
    and a filterdepth value deeper than the vehicle's track. Second, when
    an AUV or ROV is operated at shallow depths, the pressure
    values used to determine depth are affected by waves at the sea surface. In this
    case, a longer period filterlength (e.g. 10 seconds) and a shallower
    filterdepth (e.g. 50 meters) may be used to lessen the artifacts due to
    surface swell.
    -S

    sidescansource

    This option specifies the data record type source of the backscatter data
    used to generate pseudo-sidescan data from Reson multibeam sonars. If
    sidescansource = 'C' then the sidescan will be derived from calibrated
    "snippet" records, if the sidescansource = 'S' then the sidescan will be derived from "snippet" records. If sidescansource = 'B' then the sidescan will be derived from "backscatter"
    records. The difference is that the "backscatter" records contain port and
    starboard time series derived from beams formed with a large acrosstrack
    beamwidth, and the "snippet" records contain short sections of beamformed
    time series centered on the bottom return times in each of the valid bathymetry
    beams.
    -T

    timelag

    This option specifies a timelag value in seconds to be applied
    to the navigation and attitude data prior to it being merged with the
    bathymetry. If timelag is a valid path to a file containing time
    stamp and time lag pairs, then these data will be read and the time lag
    applied to particular records will be interpolated by time.
    -W

    dslfile

    The program will read navigation and attitude from the WHOI DSL navigation
    and attitude file dslfile and merge those data with the multibeam, sidescan,
    and subbtottom data in the 7k file.If a timelag model is specified using
    -Ttimelag, the time lag will be applied to the navigation and
    attitude data before merging with the sonar data. Any pre-existing navigation data
    records will be replaced. The similar -Ninsfile and -Wdslfile
    options cause merging of data from MBARI AUV logfiles and WHOI DSL navigation files,
    respectively. The WHOI DSL navigation and attitude file is a text file with
    eleven space delimited columns:

            PPL date time vehicle latitude longitude depth heading pitch roll id

    where:

            PPL - tag indicating processed navigation and attitude

            date - yyyy/mm/dd

            time - hh:mm:ss.sss

            vehicle - SEN for Sentry

            latitude - decimal degrees

            longitude - decimal degrees

            depth - sonar depth in meters

            pitch - decimal degrees

            roll - decimal degrees

            id - seems to be 1.00

    EXAMPLES

    Suppose that one has collected a Reson 7k datafile incorporating
    multibeam sonar data, sidescan data, and subbottom profiler data, and
    that the filename is:

            20050418_150155.s7k

    In order to preprocess the data in a 7k data file, one can use
    mb7kpreprocess with no special arguments:

            mb7kpreprocess -I 20040722_152111.s7k

    SEE ALSO

    mbsystem(1), mbformat(1), mbinfo(1)

    BUGS

    Oh yeah.

     Index

    NAME
    VERSION
    SYNOPSIS
    DESCRIPTION
    AUTHORSHIP
    OPTIONS
    EXAMPLES
    SEE ALSO
    BUGS

Last Updated: 12 November 2014

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