driftertrajWMLE_1.01.tar.gz is a gzip-compressed tar archive that contains 12287 individual files named dX, one per selected Argos-tracked drifter trajectory with the Global Drifter program ID X. This is version 1.01 of the dataset described in Elipot et al. 2016, "A global surface drifter dataset at hourly resolution", JGR-Oceans, doi:10.1002/2016JC011716. For this 1.01 update, we have selected all Argos-tracked drifter trajectories in the GDP database up to July 2016 for which the average uneven sampling time interval per trajectory is 3 hours or less. Previously (version 1) we had selected all trajectories after January 1 2005, irrespectively of the sampling interval. 

Upon uncompressing the archive, you should find 12287 files in a directory called "individual_1.01".

Each file is an ASCII text file with contiguous hourly estimates, one set of hourly estimates per line, unless the interpolating temporal gap between orginal Argos positions is longer than 12 hour. In that case, no estimate is provided. When analyzing these data as time series, be aware of temporal time steps that are multiple of 1 hour. You may want to consider the netcdf file for these data that indicates interruptions in contiguous hourly estimates by "Infinity" values; and separation of individual trajectories by "NaN" values.

1 : identification number from the Global Drifter Program (see deployment log file at http://www.aoml.noaa.gov/phod/dac/deployed.html)
2 : year
3 : month
4 : day
5 : hour of the day (UTC, 0-23)
6 : longitude (degree 0-360)
7 : latitude (degree North)
8 : longitude error (10^-5 degree) forming 95% confidence intervals
9 : latitude error (10^-5 degree) forming 95% confidence intervals
10 : zonal velocity (meter per second)
11 : meridional velocity (meter per second)
12 : zonal velocity error (meter per second) forming 95% confidence intervals
13 : meridional velocity error (meter per second) forming 95% confidence intervals
14 : length of interpolating gap in days; it is the difference between the time of the first Argos fix forward in time minus the time of the last Argos fix backward in time
15 : root mean square temporal distance in days between the hourly interpolating time and the four Argos fixes used for the estimation (three Argos fixes for beginning and end of trajectory).
16 : drogue status; 1 = drogue on, 0 = drogue off

Questions about the dataset should be addressed to either Rick.Lumpkin@noaa.gov, Renellys.Perez@noaa.gov, or Shane Elipot at selipot@rsmas.miami.edu