The directory rawnav located in directory nav contains the raw navigation that was collected during the sidescan-sonar component of the field program using a USGS differential GPS system (Ashtech). These files represent the data that was originally recorded on floppy disk aboard ship. The data are in NEMA format, but only contain the $GPGGA string. WARNING: These data have not been checked for errors. Use with caution.
To aid viewing of the original raw navigation data, each data entry was reformatted (removing the NEMA codes) by filtering the raw data files through a UNIX awk script. (see README ; SCRIPTS sub-directory within the NAV directory). Every navigation fix from the original data has been preserved, however.
The navigation is stored in ASCII files using six fields separated by tabs, with each file representing a separate julian day (i.e. jd128web.txt). Navigation fixes are at 10 second intervals. These files are located in the NAV sub-directory.