The databases for port_trk and stbd_trk line maps contain the ship's center track line lat/lon starting and ending position, not the starting and ending position of the outward beams. Positions for the start and end points of the outward beams are encoded in the map data and may be extracted with e.g. the v.to.db module.
The v.patch module can be used to group many scan lines together
into the same map. See the GRASS
MB-System wiki page
for details and many examples.
If you want to patch the tracks together later it is suggested to extract
some sort of integer from the input filename to set as the category
number. GRASS vector maps must have SQL compliant names, i.e. they
may not start with a number or contain characters such as "." or "-".
If attributes for all maps are stored in a central database, for example SQLite or Postgres, an assortment of SQL database queries can be made.
for TYPE in track swath ; do COUNT=0 for TRACK in `cut -f1 -d' ' datalist-1` ; do COUNT=`expr $COUNT + 1` OUTNAME="${TYPE}_$( echo "`basename $TRACK .fnv`" | sed -e 's/[- .]/_/g' )" echo "Importing <$OUTNAME> ..." v.in.mbsys_fnv in="${TRACK}.fnv" out="$OUTNAME" type=$TYPE cat=$COUNT done done
#FILENAME="MB2004-132-1219.xtf.fnv" OUTNAME=track_MB2004_132_1219_xtf CAT=`echo "$OUTNAME" | cut -f3,4 -d'_' | tr -d '_'` # cat is now set as 1321219
Find all track files within a given bounding box on julain day 261 with a track length shorter than 500 meters:
echo "SELECT filename FROM datalist_tracks \ WHERE length_m < 500 AND julian_day = 261 AND \ bbox_north <= 40.4 AND bbox_south > 40.3 AND \ bbox_west > -73.75 AND bbox_east <= -73.5" | db.select
db.select sql="SELECT length_m, filename, start_time \ FROM datalist_tracks WHERE length_m < 500"
Last changed: $Date: 2011-11-08 13:56:45 -0800 (Tue, 08 Nov 2011) $
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