MB-System Unix Manual Page

mbmask

Section: MB-System 5.0 (l)
Updated: 9 August 2001
Index

NAME

mbmask, mbgetmask - Extract swath bathymetry data flags from one file and apply to another.

VERSION

Version 5.0

SYNOPSIS

mbgetmask [-Fformat -Byr/mo/da/hr/mn/sc -Eyr/mo/da/hr/mn/sc -Sspeed -Iinfile -V -H]
mbmask [-Fformat -Mmaskfile -Iinfile -Ooutfile -V -H]

DESCRIPTION

Swath bathymetry data is typically edited either with interactive tools such as mbedit or automatic filters such as mbclean. The beams which are deemed "bad" are flagged. Occasionally, the need arises to translate data flagging information from one file to another which represents a different version of the same dataset. In particular, it may happen that editing has been done on a data format which does not support all of the original data stream (e.g. the edmb Hydrosweep format 22, which does not contain travel times or amplitudes), but the user now wishes to work with the complete data stream without having to redo the editing process.

The two utilities mbgetmask and mbmask allow the user to extract the flagging information in the form of a "mask" file from the edited file and then to apply the flagging mask to another file containing a different version of the same data. The first utility, mbgetmask, is used to extract the mask from the edited swath bathymetry file; the output is written to stdout. The second utility, mbmask, reads in the mask file and the unedited swath data file and flags or unflags all beams indicated by the mask. The mask is keyed to the times of the individual pings; only exactly corresponding pings will be affected by the mask.

AUTHORSHIP

David W. Caress (caress@mbari.org)

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

Lamont-Doherty Earth Observatory

MBGETMASK OPTIONS

-B: yr/mo/da/hr/mn/sc
This option sets the starting time for data allowed in the input data. The -E option sets the ending time for data. If the starting time is before the ending time, then any data with a time stamp before the starting time or after the ending time is ignored. If instead the starting time is after the ending time, then any data between the ending and starting time will be ignored. This scheme allows time windowing both inside and outside a specified interval. Default: yr/mo/da/hr/mn/sc = 1962/2/21/10/30/0.
-E: yr/mo/da/hr/mn/sc
This option sets the ending time for data allowed in the input data. The -B option sets the starting time for data. If the starting time is before the ending time, then any data with a time stamp before the starting time or after the ending time is ignored. If instead the starting time is after the ending time, then any data between the ending and starting time will be ignored. This scheme allows time windowing both inside and outside a specified interval. Default: yr/mo/da/hr/mn/sc = 2062/2/21/10/30/0.
-F: format
Sets the format for the input and output swath data using MBIO integer format identifiers. These utilities uses the MBIO library and will read any swath data format supported by MBIO. A list of the swath data formats currently supported by MBIO and their identifier values is given in the MBIO manual page.
-H: This "help" flag causes the program to print out a description of its operation and then exit immediately.
-I: infile
Data file from which the input data will be read. If no input file is specified, the input will be read from stdin. Default: infile = stdin.
-S: speed
Sets the minimum speed in km/hr (5.5 kts ~ 10 km/hr) allowed in the input data; pings associated with a smaller ship speed will not be copied. Default: speed = 0.
-V: Normally, mbgetmask works "silently" without outputting anything to the stderr stream. If the -V flag is given, then mbmask works in a "verbose" mode and outputs the program version being used and all error status messages.

MBMASK OPTIONS

-H: This "help" flag causes the program to print out a description of its operation and then exit immediately.
-F: format
Sets the format for the input and output swath data using MBIO integer format identifiers. These utilities uses the MBIO library and will read any swath data format supported by MBIO. A list of the swath data formats currently supported by MBIO and their identifier values is given in the MBIO manual page.
-I: infile
Data file from which the input data will be read. If no input file is specified, the input will be read from stdin. Default: infile = stdin.
-M: maskfile
Input file containing a data flagging mask created by mbgetmask.
-O: outfile
Data file to which the output data will be written. If no output file is specified, the output will be written to stdout. Default: outfile = stdout.
-V: Normally, mbmask works "silently" without outputting anything to the stderr stream. If the -V flag is given, then mbmask works in a "verbose" mode and outputs the program version being used and all error status messages.

EXAMPLES

Suppose one has an edmb format (MBIO format id 22) Hydrosweep file called hs_ew9103_143.mb22 which has been edited until the data is just right. Further suppose that one's thesis advisor suggests that the bathymetry would be better if it were recalculated from travel times using a new water velocity model, requiring that the raw Hydrosweep data (originally collected in format 5 but recently translated to format 24) in the file hs_ew9103_143.mb24 be used. First extract the editing information in the form of a flagging mask file from the edited edmb file:
mbgetmask -F22 -Ihs_ew9103_143.mb22 > hs_ew9103_143.mask

Then, apply the mask to the raw file as follows:
mbmask -F24 -Mhs_ew9103_143.mask -Ihs_ew9103_143.mb24 -Ohs_ew9103_143_m.mb24