Process GPS log of Sony camera

gistfile1.sh

# Sony camera emits GPS data in NMEA format [1]
#
# The $GPRMC records contain velocity
#
# $GPRMC,043151.097,A,5203.5674,N,513.4071,E,14.56,,010814,,,A*43
#        ^          ^ ^           ^          ^      ^         ^
#        |          | |           |          |      |         \-Checksum
#        |          | |           |          |      |          
#        |          | |           |          |      \- date, ddmmyy
#        |          | |           |          \-------- velocity in knots
#        |          | |           \------------------- longitude: 4º51.2579E
#        |          | \------------------------------- latitude: 52º23.1071'N
#        |          \--------------------------------- status, active or void
#        \-------------------------------------------- time hhmmss in UTC
#
#
# [1]: http://www.gpsinformation.org/dale/nmea.htm

# Output date in "ddmmyyHHMMSS+0000" format
# This drops the milliseconds, but the equipment isn't all that accurate anyway
awk -F ',' '/^\$GPRMC/{ print $10 substr($2,1,6) "+0000" }'

# Parse said format and convert from UTC to the local time zone
date -jf '%d%m%y%H%M%S%z' '010203040506+0000' +'%a %b %d %C%y %H:%M:%S'

# The date formatting in awk (blergh)
awk -F ',' '/^\$GPRMC/{\
  timestamp=$10 substr($2,1,6) "+0000" ;\
  formatcommand="date -jf \"%d%m%y%H%M%S%z\" \""timestamp"\" +\"%a %b %d %C%y %H:%M:%S\"";\
  formatcommand | getline formatteddate;\
  close(formatcommand);\
  print formatteddate }'

# The coordinate formatting in awk
awk -F ',' '/^\$GPRMC/{\
  lat_degrees=substr($4,1,index($4,".")-3);\
  lat_minutes=substr($4,index($4,".")-2);\
  lon_degrees=substr($6,1,index($6,".")-3);\
  lon_minutes=substr($6,index($6,".")-2);\
  print lat_degrees "º" lat_minutes $5 "," lon_degrees "º" lon_minutes $7 }'

# Adding the other variables in output
awk -F ',' '/^\$GPRMC/{\
  timestamp=$10 substr($2,1,6) "+0000" ;\
  formatcommand="date -jf \"%d%m%y%H%M%S%z\" \""timestamp"\" +\"%a %b %d %C%y %H:%M:%S\"";\
  formatcommand | getline formatteddate;\
  close(formatcommand);\
  knots=$8;\
  kmh=$8 * 1.852;
  lat_degrees=substr($4,1,index($4,".")-3);\
  lat_minutes=substr($4,index($4,".")-2);\
  latitude=lat_degrees "º" lat_minutes $5;\
  longitude=lon_degrees "º" lon_minutes $7;\
  lon_degrees=substr($6,1,index($6,".")-3);\
  lon_minutes=substr($6,index($6,".")-2);\
  print formatteddate "," latitude "," longitude "," int(kmh) " km/h" }'

# Column formatting of CSV
column -t -s,