Amundsen Heading Analysis Scripts & Process

useCMG.c was modified to spit out difference between headings and file name

The following command filtered pertinent data out and did a little math (from Jonnyb, Highway 1, N.S.): 
useCMG -test $1 -v | grep -v extracted | \
grep -v "working on" | sed -e 's/:/ /g' | awk '{printf("%.5f %.2f %.1f %s\n", $2+$3/24+$4/1440+$5/86400,$9-$14,$16, $17);}' | \
sed -e 's/-//' | awk '{if ($2 > 300) {print $1, 360 - $2, $3, $4} else {print $_} }' | sort -n >! junk.dat
Before: 
working on 000-002/0017_20070729_124930.merged
extracted from 50 of 1178
2007 210 12:49:29 ping 0 GYRO 336.82  --- CMG 331.48  NEW_GYRO 335.42 SOG 3.31 000-002/0017_20070729_124930.merged
2007 210 12:49:31 ping 1 GYRO 336.35  --- CMG 331.48  NEW_GYRO 335.42 SOG 3.31 000-002/0017_20070729_124930.merged
2007 210 12:49:32 ping 2 GYRO 335.97  --- CMG 336.16  NEW_GYRO 335.42 SOG 13.02 000-002/0017_20070729_124930.merged
2007 210 12:49:34 ping 3 GYRO 335.68  --- CMG 335.87  NEW_GYRO 335.42 SOG 12.87 000-002/0017_20070729_124930.merged
After: (Decimal Julian Day, Delta Heading, Speed, Filename) 
210.53436 1.40 3.3 000002/0017_20070729_124930.merged
210.53439 0.93 3.3 000002/0017_20070729_124930.merged
210.53440 0.55 13.0 000002/0017_20070729_124930.merged
210.53442 0.26 12.9 000002/0017_20070729_124930.merged

The plot config file for Gnuplot was built with mk_plot_load.conf
A sample plot config file is: plot_load.conf

The following lines set up the overall plot window: 

set size 2,1
set origin 0,0
set multiplot
And this is the setup for one of the plots: 
set size 1,0.5
set origin 0,0.5
set grid
set xlabel "Julian Day"
set ylabel "Delta Heading"
set title "Heading Analysis -- 0346_20070905_091736.merged"
set key left box
plot "junk.dat" using 1:2 index 0 title "Delta Heading (degrees)" with lines
To use the conf file pipe it to gnuplot: 
cat plot_load.conf | gnuplot
Here's one of the plots made this way:

Notice the madly diverging heading at high speed.

As part of the initial do_check script, the output as seen above is also cat'd into a larger project .dat file.

The file plot_all-solutions.conf configures the gnuplotting of speed vs. delta heading, with a form of a 1/x function plotted on top. This function is just a crude approximation that is used as a cutoff for flagging problem data.

The result is this plot:

At 12 and 15 knots, the difference between course-made-good and the motion sensor's heading should not be 90 degrees, there's definitely a problem here. Also, the Amundsen doesn't meet Transport Canada's requirements for ludicrous speed, so 20+ knots ain't happenin.

Lastly, the modified 1/x function is used to flag data which is then cat'd into a new file (it must be touched before this command will work). 

cat 015_mclintock_solutions_re-unravelled.dat | awk '{ if ($2-1 != 0.0 && $2 > 1.0 && $3 > 5) if ($3 > 100/($2-1)+0.75) \
print $1" "$2" "$3" "100/($2-1)+0.75" "$4}' >> 015_mclintock_solutions_re-unravelled_flagged.dat
The output of this last step is (Decimal Julian Day, Delta Heading, Speed, Function Cutoff, filename): 
286.02966 89.54 15.1 1.87943 015_Mclintock_reunravelled/0168_20071013_004242.merged
286.02968 89.73 15.1 1.87701 015_Mclintock_reunravelled/0168_20071013_004242.merged
286.02968 89.83 15.4 1.87575 015_Mclintock_reunravelled/0168_20071013_004242.merged
286.02969 90.20 15.7 1.87108 015_Mclintock_reunravelled/0168_20071013_004242.merged
286.02969 90.54 15.5 1.86682 015_Mclintock_reunravelled/0168_20071013_004242.merged

Created February 29, 2008 by Steve Brucker