MB-System Unix Manual Page


Section: MB-System 5.0 (1)
Updated: 17 March 2016


mbkongsbergpreprocess - performs preprocessing of data from third generation Kongsberg multibeam sonars (e.g. EM122, EM302, EM710, EM2040, M3).



Version 5.0



mbkongsbergpreprocess [-C -Doutputdirectory -Eoffx/offy[/offdepth] -Fformat -Ifile -Ooutfile -Pfilterlength/filterdepth -Sdatatype/source -Ttimelag -W -H -V]



mbkongsbergpreprocess reads data from a third generation Kongsberg multibeam sonar (e.g. EM122, EM302, EM710, EM2040, M3), interpolates the asynchronous navigation, heading, and attitude onto the multibeam data, and writes a new file with that information correctly embedded in the multibeam survey data. The input files may be in the vendor format MBF_EM710RAW (format id 58) or the MB-System extended format MBF_EM710MBA (format id 59); the output files will always be in the MB-System extended format MBF_EM710MBA (format id 59).

Like most modern swath survey data streams, Kongsberg multibeam data includes navigation, attitude, and heading data logged in separate data records as output by the respective sensors. Since each of these values is time stamped according to its origin rather than synced with multibeam pings, these values are asynchronous relative to the survey ping data. When multiple sources of navigation, heading, and/or attitude have been recorded in a data stream, mbkongsbergpreprocess allows the user to specify which asynchronous data are extracted and interpolated onto the survey data using the -S option.

This program allows the correction of a time latency (or time lag) error between the sonar data and the attitude and navigation data using the -T option.

The format 58 files This program also creates four ancilliary files containing the full asynchronous attitude, sonar depth, and heading data and the synchronous attitude data in parallel with each output format 59 file. These files are used, when present, by mbeditviz to facillitate interactive analysis of time lag issues. Each of these are text files with white-space delimited columns; the first column is always time in decimal unix seconds. These have the following suffixes:
    asynchronous attitude (roll and pitch):     *.ata

    asynchronous heading:                       *.ath

    asynchronous sonar depth:                   *.ats

    synchronous attitude (roll and pitch):      *.sta

     By default, mbkongsbergpreprocess ignores water column records and does not pass these large records into the output format 59 files. The -W1 option causes the water column records to be written in the output files.



David W. Caress (caress@mbari.org)

  Monterey Bay Aquarium Research Institute
Dale N. Chayes (dale@ldeo.columbia.edu)

  Lamont-Doherty Earth Observatory




This option causes mbkongsbergpreprocess to print counts of the many different data record types compising a Kongsberg data stream. The data record counts are output for each file and as totals from all files processed.
This option causes all format 59 output files to be placed in the specified directory outputdirectory rather than parallel to the original "raw" files.
This option is for data from submerged platforms such as ROVs or AUVs. This 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.
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 third generation Kongsberg multibeam format data files (MBIO formats 58 and 59).
This "help" flag cause the program to print out a description of its operation and then exit immediately.
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.:
        datafile.all 58

        datafile.all 58

This program only reads third generation Kongsberg multibeam format data files (MBIO formats 58 and 59).
This option causes mbkongsbergpreprocess to output all data to a single file specified as outfile. By default, the program creates output files for each input file. If the -Doutputdirectory option is also used, then the output file outfile will be in outputdirectory.
filterlength/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.
This option specifies which data records should be the source of the navigation (datatype = 1), heading (datatype = 2), attitude (datatype = 3), and sonar depth (datatype = 4) data that are interpolated onto the survey ping times. In each case the source value specifies a data record type. The possibilities for Kongsberg data include:
     MB_DATA_DATA               1

     MB_DATA_NAV                12

     MB_DATA_HEIGHT             16

     MB_DATA_HEADING            17

     MB_DATA_ATTITUDE           18

     MB_DATA_NAV1               28

     MB_DATA_NAV2               29

     MB_DATA_NAV3               30

     MB_DATA_ATTITUDE1          55

     MB_DATA_ATTITUDE2          56

     MB_DATA_ATTITUDE3          57

The default sources for position, heading and sensor depth are:
     nav_source = MB_DATA_NAV
     heading_source = MB_DATA_NAV
     sonardepth_source = MB_DATA_DATA
The default source for attitude is set according to the sensor that was active during data collection, most often:
     attitude_source = MB_DATA_ATTITUDE 
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.
By default, mbkongsbergpreprocess ignores water column records and does not pass these large records into the output format 59 files. If -W1 is specified, then the water column records will be written to the output files.



Suppose that one has collected a set of three Kongsberg EM122 data files named:
First, we want to generate a "datalist" file referencing the raw survey files. The following will suffice:
    /bin/ls -1 *all | awk '{print $1" 58"}' > datalist_raw.mb-1
We want to use mbkongsbergpreprocess to gracefully interpolate the asynchronous navigation, heading and attitude data onto the survey data and to generate data files in the extended format (MBF_EM710MBA = 59). To learn which potential sources of navigation, heading and attitude are available, use mbinfo with the -N option:
    $ mbinfo -I 0000_20111219_154640_METEOR_EM122.all -N

The -N option causes mbinfo to generate a list of the data record types read in the file at the end of the file statistics:

    Swath Data File:      0000_20111219_154640_METEOR_EM122.all
    MBIO Data Format ID:  58
    Format name:          MBF_EM710RAW
    Informal Description: Kongsberg current multibeam vendor format
    Attributes:           Kongsberg EM122, EM302, EM710,
                          bathymetry, amplitude, and sidescan,

                          up to 400 beams, variable pixels, binary, Kongsberg.

    Data Totals:
    Number of Records:                         334
    Bathymetry Data (432 beams):
      Number of Beams:           144288
      Number of Good Beams:      129951     90.06%
      Number of Zero Beams:           0      0.00%
      Number of Flagged Beams:    14337      9.94%
    Amplitude Data (432 beams):
      Number of Beams:           144288
      Number of Good Beams:      129951     90.06%
      Number of Zero Beams:           0      0.00%
      Number of Flagged Beams:    14337      9.94%
    Sidescan Data (1024 pixels):
      Number of Pixels:          342016
      Number of Good Pixels:     289910     84.77%
      Number of Zero Pixels:          0      0.00%
      Number of Flagged Pixels:   52106     15.23%

    Navigation Totals:
    Total Time:             0.8327 hours
    Total Track Length:    13.6418 km
    Average Speed:         16.3823 km/hr ( 8.8553 knots)

    Start of Data:
    Time:  12 19 2011 15:46:27.537000  JD353 (2011-12-19T15:46:27.537000)
    Lon:   -11.562232000     Lat:    36.848179850     Depth:  4931.4829 meters
    Speed: 17.6040 km/hr ( 9.5157 knots)  Heading: 129.1900 degrees
    Sonar Depth:    5.6975 m  Sonar Altitude: 5025.2964 m

    End of Data:
    Time:  12 19 2011 16:36:25.308000  JD353 (2011-12-19T16:36:25.308000)
    Lon:   -11.489473500     Lat:    36.771997400     Depth:  3242.5244 meters
    Speed: 12.7800 km/hr ( 6.9081 knots)  Heading: 274.9200 degrees
    Sonar Depth:    6.4334 m  Sonar Altitude: 3236.0911 m

    Minimum Longitude:     -11.635798757   Maximum Longitude:     -11.391532562
    Minimum Latitude:       36.723994163   Maximum Latitude:       36.919907119
    Minimum Sonar Depth:     5.0135   Maximum Sonar Depth:     6.9798
    Minimum Altitude:     3175.1121   Maximum Altitude:     5027.8770
    Minimum Depth:        2391.9229   Maximum Depth:        5121.0713
    Minimum Amplitude:     -59.2000   Maximum Amplitude:      -9.1000
    Minimum Sidescan:      -90.1300   Maximum Sidescan:       -0.4700

    Data Record Type Notices:
    DN: 334 MB_DATA_DATA (ID=1): survey data
    DN: 1 MB_DATA_START (ID=10): Simrad start datagram
    DN: 1 MB_DATA_STOP (ID=11): Simrad stop datagram
    DN: 3023 MB_DATA_NAV (ID=12): Navigation record
    DN: 287 MB_DATA_RUN_PARAMETER (ID=13): Simrad runtime parameter datagram
    DN: 3022 MB_DATA_CLOCK (ID=14): Simrad clock datagram
    DN: 2964 MB_DATA_ATTITUDE (ID=18): Attitude record
    DN: 731 MB_DATA_SSV (ID=19): Surface sound speed record
    DN: 3022 MB_DATA_NAV3 (ID=30): Auxiliary nav system 3
    DN: 3023 MB_DATA_STATUS (ID=46): Status record
    DN: 2964 MB_DATA_ATTITUDE1 (55): ancillary attitude system 1
    DN: 1512 MB_DATA_ATTITUDE2 (56): ancillary attitude system 2

    Nonfatal Error Notices:
    EN: 20551 MB_ERROR_NO_DATA_REQUESTED (ID=-11): No data requested for buffer load

    Problem Notices:

This listing shows that the format 58 file includes MB_DATA_NAV (source = 12) and MB_DATA_NAV3 (source = 30) records, both of which include both position and heading data. Also included are three sources of attitude data: MB_DATA_ATTITUDE (source = 18), MB_DATA_ATTITUDE1 (source = 55), and MB_DATA_ATTITUDE2 (source = 56).

To extract and use the default navigation, heading, and attitude data, the following will suffice:
    mbkongsbergpreprocess -I datalist_raw.mb-1 -V

An equivalent command that explicitly specifies the default asynchronous data sources using -S1/source for navigation, -S2/source for heading, and -S3/source for attitude is:
    mbkongsbergpreprocess -I datalist_raw.mb-1 -V -S1/12 -S2/12 -S3/18

To interpolate navigation and heading from the secondary navigation source, use
    -S1/30 -S2/30

To interpolate attitude from ancillary attitude system 2, use:



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



Not true bugs. More like arachnids.




Last Updated: 17 March 2016

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