MBPS
Section:  MB-System 5.0  (1)
Updated:  3 June 2013 
Index


 
NAME

mbps - Generates a PostScript perspective plot of a piece of swath sonar data.

 
VERSION

Version 5.0

 
SYNOPSIS

mbps [-Fformat -Ifilename -Nnpingsmax -Ppings
-Aalpha -Byr/mo/da/hr/mn/sc
-Dview_direction -Eyr/mo/da/hr/mn/sc -Ggap
-Keta -Sspeedmin -T"title" -Xve
-Wmeters_per_inch -Ydisplay_stats -Zdisplay_scales
-V -H]

 
DESCRIPTION

mbps is a utility to generate an (almost correct) perspective view
of a piece of swath sonar data. It is especially useful to get a detailed
view of the quality of the data (which is not very well assessed in a contour
plot) and to make pretty pictures of features that fit within a swath.
The output is PostScript code, that can be piped to a PostScript printer, or to a file.
The options are a bit hard to interpret without a picture. Consider a
frame of reference tied to the ship, with z upward, x across the track
(port being negative, starboard positive) and y along the track. Using
the -D option, the data can be viewed from port, starboard,
or from the back. In the first two cases, the y-axis is horizontal in
the plot; in the third case, the x-axis is horizontal.  The angle alpha
is the angle between the x-axis and the y-axis in the final view; eta is the angle of elevation of the observing point (90 degrees being the zenith).  The
data points are plotted as triangular polygons with the vertices at three good (ie. unflagged) adjacent data points. A given point is adjacent to 8 points in the surrounding swath (top, bottom, 2 sides, and 4 corners).  Now that you are thoroughly
confused, just try plotting a half-hour or so of data from your favorite
place. The defaults are such that a decent plot should come out.
The plot will be scaled automatically to fit on a page, and will contain vertical and horizontal scales, an arrow pointing in the direction of the ship's motion, coordinate axes, and miscellaneous
information identifying the piece of data being plotted.
Now change some of the options, and things should get clearer.

 
AUTHORSHIP

Russ T. Alexander




  Formerly at University of California at Santa Barbara



Alberto Malinverno (now at Schlumberger)




  Lamont-Doherty Earth Observatory

 
OPTIONS


-A


alpha



Sets the angle alpha (degrees) between the y-axis (shiptrack direction) and
the x-axis (across-track). Default = alpha = 70.
-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.
-D


view_direction



Sets the viewing direction; viewdir is a single character, either
P/p (view from the port side), S/s (starboard), or B/b (back). Default
view_direction = S.
-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 swath sonar data using
MBIO integer format identifiers.
This program uses the MBIO library and will read 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: format = 11.
-G


gap



Sets the manner in which data gaps are displayed.  If gap = 1 then
gaps are filled with black.  If gap = 0 then gaps are not filled and appear the same as the background color of the paper.
Default: gap = 1.
-H


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


filename



File from which the input data will be read. If
no input file is specified, the input will be read
from stdin. Default: filename = stdin.
-K


eta



Sets the angle eta (degrees) that is the elevation of the observer over
the plane defined by the mean depth. Default eta = 45.
-N


npingsmax



Sets the maximum number of pings to be read and plotted.
Default: npingsmax = 1000.
-P


pings



Sets the ping averaging of the input data. If pings = 1, then
no ping averaging is performed. If pings > 0, then
that number of input pings will be averaged to produce one output
ping.  If pings = 0, then the ping averaging will automatically
be done so that the along-track ping spacing is equal to the across-track
beam spacing.
Default: pings = 1 (no ping averaging).
-S


speedmin



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 used. Default: speed = 0.
-T


"title"



Sets the title printed at the top of the plot.  The title should be enclosed within double quotes.  Default: no title.
-V


If the -V flag is given, then mbps works in a "verbose" mode and
outputs the program version being used and all read error status messages.
-W


meters_per_inch



Sets the horizontal plotting scale.  Default: automatically calculates
a scale such that the plot fits on a page.
-X


ve



Sets the vertical exaggeration. Default ve = 5.
-Y


display_stats



Sets whether the final plot includes info such as mean latitude, mean longitude, mean heading, alpha, eta, ve, scale, track length, begin time, and end time. if display_stats = 1 then the above info is plotted; if dispaly_stats = 0 then it is not plotted.  Default: display_stats  = 1.
-Z


display_scales



Sets whether the final plot includes a horizontal scale, a vertical scale, an arrow pointing in the ship heading direction, and coordinate axes.  if display_scales = 1 then the above info is plotted; if dispaly_scales = 0 then it is not plotted.  Default: display_scales  = 1.


 
EXAMPLES

Suppose one wishes to take a look at data from a Hydrosweep file in
L-DGO edmb format (data.edmb), starting at 09:00 and ending at
10:30 on September 3, 1991. The following will output PostScript to a file called fred.


        mbps -F22 -Idata.edmb -B1991/9/3/9/0/0 -E1991/9/3/10/30/0 > fred


 
SEE ALSO

mbsystem(1), mbcontour(1), mbswath(1)

 
BUGS

mbps assumes that the ship was moving on a straight line. Weird
plots will result if this is not the case.  mbps only draws polygons bewteen 3 adjacent good points; if isolated points without 2 neighbors exist they will not be apparent in the final plot.  The filling of bad polygons is not perfect and gaps in the black fill, especially at the edges of swaths, may occur.



 
Index

NAME

VERSION

SYNOPSIS

DESCRIPTION

AUTHORSHIP

OPTIONS

EXAMPLES

SEE ALSO

BUGS

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