Technical document

1. Organization of the Database

Scientific and technical information on the drifters are provided in the Scientific document page.

Plots of the drifter data (time series and tracks) can be accessed in three ways:

1) With a search tool (Search page) in which the files corresponding to a given drifter ID number are listed and can be selected.

2) Through a image navigator (Image navigator page)  which allows to view the plots in sequenctial order

3) From a master directory table  (Master table page) by clicking on the file name in the first column.

Data files are located in the Data access page. The drifter data are provided both at the edited and kriged levels.


2. Data formats

The file names are composed of the Argos ID number of the drifter with a prefix (a,b,c,...) corresponding to different separate tracks of the same drifter,  and followed by an extension indicating the data type.

The edited data are available in ASCII files. For all the drifters , the files (a####.ed) contain:

       Column #1 : Matlab time (serial days where 1 corresponds to 01-Jan-0000)
       Column #2 : Latitude (deg N)
       Column #3: Longitude (deg E)
       Column #4: Quality index (3,2,1: ARGOS; 5,4: GPS)
       Column #5: Drifter voltage (Volt)
       Column #6: Sea surface temperature (deg C)

The low-pass filtered and interpolated (kriged) drifter data are available in MATLAB binary files (a####_kri.mat). The following parameters are provided:

        time = MATLAB time (serial days where 1 corresponds to 01-Jan-0000)
        lon = Longitude (deg E)
        lat = Latitude (deg N)
        sst = Temperature (deg C)
        u = East-West component of velocity (cm/s)
        v = North-south component of velocity (cm/s)