The format of the columns of information are as follows:
$GPGGA, UTC time, latitude (DDMM.MMMM), latitude hemisphere, longitude (DDMM.MMMM), longitude hemisphere.
The first row in each file describes the file.
Latitude: (4211.9672-4200)/60+(42) to give 42.19945 decimal degrees
Longitude: (((7043.2105-7000)/60) + 70) * -1 to give -70.72018 decimal degrees with negative for western hemisphere
Additional fields of information were added to the spreadsheet and are defined in the entity and attribute section, as well as within the header information in each spreadsheet. The first row is an explanation header, the second row contains descriptive column headers, and the third row contains brief column headers that are compatible with importing the data into a GIS. These reformatted files omit the transit navigation to and from the port to the study area based on time in the file. The filenames indicate the cruise and day of navigation. The reformatted version of the navigation excludes the transit navigation between the port and the study area. The original GPGGA navigation filenames are in the format AUK2017030_XXXX_UTC_nav_raw.csv where XXXX is the day of navigation (for example 18may2017). The filenames of the reformatted navigation are in the format AUK2017030_station_nav_log_XXXX_UTC where XXXX is the day of navigation (for example 18MAY2017); the filename suffix is either XLSX or CSV.
GPS navigation log: Column A, vessel name, AUK, SBNMS research vessel; column B, field activity number; column C, date, UTC; column D, Julian Day, UTC; column E, study area time zone; column F, time, UTC (for Eastern Daylight Time subtract 4 hours); column G, latitude north, degrees and decimal minutes; column H longitude west, degrees and decimal minutes; column I, latitude north, decimal degrees; column J, longitude west, decimal degrees; column K, geographic region [abbreviations: D, degrees; H, hour; M, minute; S, second; EDT, Eastern Daylight Time; lat, latitude; lon, longitude; WHCMSC, USGS Woods Hole Coastal and Marine Science Center; SBNMS, Stellwagen Bank National Marine Sanctuary; UTC, coordinated universal time (Greenwich Mean Time, ZULU time); GPS, satellite-based Global Positioning System receiver]
The columns of data are the same as represented in the entity and attribute detail information.
The files with the same prefix name, but the CSV extension are exported from the Excel spreadsheet, minus the first two rows of information.
The *_raw.csv files are the original $GPGGA strings off the ship. The format of the columns of information are as follows:
$GPGGA, UTC time, latitude (DDMM.MMMM), latitude hemisphere, longitude (DDMM.MMMM), longitude hemisphere.
The first row in the *raw.csv file describes the file.