mbclean
Section: MB-System 5.0 (1)
Updated: 16 September 2013
Index
NAME
mbclean - Tool to automatically flag bad beams in swath sonar bathymetry data.VERSION
Version 5.0SYNOPSIS
mbclean [-Amax -Blow/high -Cslope/units -Dmin/max -Fformat -Gfraction_low/fraction_high -Iinfile -Llonflip -Ooutfile -Mmode -Qbackup -Rmaxheadingrate -Sslope/mode/units -Ttolerance -Unmin -Xbeamsleft/beamsright -Ydistanceleft/distanceright -V -H]DESCRIPTION
mbclean identifies and flags artifacts in swath sonar bathymetry data. Several algorithms are available for identifying artifacts; multiple algorithms can be applied in a single pass. The most commonly used approach is to identify artifacts based on excessive bathymetric slopes. Spikes where an excessive slope occurs before and reverses after a beam can also be removed. If desired, mbclean will also flag beams associated with "rails" where outer beams have smaller acrosstrack distances than more inner beams (-Q option). Low and high bounds on acceptable depth values can be set; depth values outside the acceptable range will be flagged. The acceptable depth ranges can either be absolute (-B option), relative to the local median depth (-A option) or defined by low and high fractions of the local median depth (-G option). A set number of outer beams can also be flagged.The order in which the flagging algorithms are applied is as follows:
1. Flag specified numbers of outer beams
(-X option).
2. Flag outer beams by acrosstrack distance
(-Y option).
3. Flag soundings outside specified acceptable
depth range (-B option).
4. Flag pings with excessive heading change rate
(-R option).
5. Zap "rails" (-Q option).
6. Flag soundings outside acceptable depth range
using fractions of local median depth
(-G option).
7. Flag soundings outside acceptable depth range
using deviation from local median depth
(-A option).
8. Flag soundings associated with spikes (-S option).
9. Flag soundings associated with excessive slopes
(-C option or default).
10. Flag all soundings in pings with too few
good soundings (-U option).
This program flags beams by outputting the flags as edit events to an "edit save file", like that produced by mbedit. If an "edit save file" (named by adding a ".esf" suffix to the input swath filename) already exists, the edits are read in and applied before the mbclean flagging algorithms are used. Once generated, the edit events can be applied to the data using the program mbprocess, which outputs a processed swath data file. The mbprocess program is also used to merge edited navigation, recalculate bathymetry, and apply other corrections to swath bathymetry data.
AUTHORSHIP
David W. Caress (caress@mbari.org)
Monterey Bay Aquarium Research Institute
Dale N. Chayes (dale@ldeo.columbia.edu)
Lamont-Doherty Earth Observatory
Alberto Malinverno
Schlumberger-DollOPTIONS
If mode is 1 (default) only acrosstrack spikes are detected. If mode is 2 only alongtrack spikes are detected. If mode is 3 both along track and across track slopes are checked.
unit is optional and specifies the unit of slope, 0 (default) indicates the slope is in tangents, 1 slope is in radians, 2 slope is in degrees. A beam is not considered a spike if either the preceding or subsequent beam has already been flagged. Default: slope = 1.0
mbclean -Idatalist.mb-1 \
-M1 -C3.5 -D0.01/0.20 \
-G0.80/1.20
The program will output flagging statistics for each file and
give totals at the end. If the -V option is specified,
mbclean will also output information for each beam that
is flagged. Here is an example of the nonverbose output:
Processing 0001_20020424_212920.mb57
908 bathymetry data records processed
0 outer beams zapped
0 beams zapped for too few good beams in ping
0 beams out of acceptable depth range
64 beams out of acceptable fractional depth range
0 beams exceed acceptable deviation from median depth
0 bad rail beams identified
1601 excessive slopes identified
0 excessive spikes identified
1665 beams flagged
0 beams unflagged
0 beams zeroed
Processing 0002_20020425_011607.mb57
259 bathymetry data records processed
0 outer beams zapped
0 beams zapped for too few good beams in ping
0 beams out of acceptable depth range
0 beams out of acceptable fractional depth range
0 beams exceed acceptable deviation from median depth
0 bad rail beams identified
242 excessive slopes identified
0 excessive spikes identified
242 beams flagged
0 beams unflagged
0 beams zeroed
Processing 0003_20020425_022926.mb57
65 bathymetry data records processed
0 outer beams zapped
0 beams zapped for too few good beams in ping
0 beams out of acceptable depth range
9 beams out of acceptable fractional depth range
0 beams exceed acceptable deviation from median depth
0 bad rail beams identified
497 excessive slopes identified
0 excessive spikes identified
506 beams flagged
0 beams unflagged
0 beams zeroed
Processing 0004_20020425_024336.mb57
410 bathymetry data records processed
0 outer beams zapped
0 beams zapped for too few good beams in ping
0 beams out of acceptable depth range
0 beams out of acceptable fractional depth range
0 beams exceed acceptable deviation from median depth
0 bad rail beams identified
148 excessive slopes identified
0 excessive spikes identified
148 beams flagged
0 beams unflagged
0 beams zeroed
Processing 0005_20020425_034057.mb57
252 bathymetry data records processed
0 outer beams zapped
0 beams zapped for too few good beams in ping
0 beams out of acceptable depth range
0 beams out of acceptable fractional depth range
0 beams exceed acceptable deviation from median depth
0 bad rail beams identified
100 excessive slopes identified
0 excessive spikes identified
100 beams flagged
0 beams unflagged
0 beams zeroed
Processing 0006_20020425_045013.mb57
562 bathymetry data records processed
0 outer beams zapped
0 beams zapped for too few good beams in ping
0 beams out of acceptable depth range
0 beams out of acceptable fractional depth range
0 beams exceed acceptable deviation from median depth
0 bad rail beams identified
41 excessive slopes identified
0 excessive spikes identified
41 beams flagged
0 beams unflagged
0 beams zeroed
MBclean Processing Totals:
-------------------------
6 total swath data files processed
2456 total bathymetry data records processed
0 total beams flagged in old esf files
0 total beams unflagged in old esf files
0 total beams zeroed in old esf files
0 total outer beams zapped
0 total beams zapped for too few good beams in ping
0 total beams out of acceptable depth range
73 total beams out of acceptable fractional depth range
0 total beams exceed acceptable deviation from median depth
0 total bad rail beams identified
2629 total excessive slopes identified
0 total excessive spikes identified
2702 total beams flagged
0 total beams unflagged
0 total beams zeroed
Last Updated: 16 September 2013