driftertrajGPS.txt contains the product of hourly location and velocity of GPS surface drifters from the Global Drifter Program as described in Elipot et al. 2016, "A global surface drifter dataset at hourly resolution", accepted for publication in the Journal of Geophysical Research - Oceans as March 2016.

The file is an ASCII text file with one hourly data entry per line, with the following 9 columns:
1 : identification number from the Global Drifter Program
2 : Julian day since 01/01/1979
3 : hour of day (UTC)
4 : longitude
5 : latitude
6 : zonal velocity in meter per second
7 : meridional velocity in meter per second
8 : length of interpolating gap in hours; it is the difference between the time of the first GPS fix forward in time minus the time of the last GPS fix backward in time
9 :  drogue status; 1 = drogue on, 0 = drogue off