Background Information:

   Data are quality controlled and optimally interpolated to uniform six hour 
interval trajectories according to the
methods described in Hansen and Polain, 1996.

   Drogued data are separated from undrogued, and only drogued data are used 
for the averages.

   Data are computed into five day averages of latitude, longitude, u, v, and 
separated into five degree by five
degree bins. Averages are only computed if there are at least sixteen data 
points (four days) available for the five
day period.

   Mean variances are computed for each five degree by five degree bin. Arrows 
are only plotted if the number of
five day averages within the bin is greater than thirty.

   REFERENCE:
    Hansen, D.V., and Pierre-Marie Poulain 1996: Quality Control and 
Interpolations of
    WOCE-TOGA Drifter Data. J. Atmos. Oceanic Technol., 13, 900-909.



==========================================================================

Understanding These Files:

   Column 1 - X Location - For Matrix Use: Index Row
   Column 2 - Y Location - For Matrix Use: Index Column
   Column 3 - Longitude - Center of the Bin
   Column 4 - Latitude - Center of the Bin
   Column 5 - Mean Longitude of Values Used to Make the Average (degrees)
   Column 6 - Mean Latitude of Values Used to Make the Average  (degrees)
   Column 7 - Mean u Velocity                                   (cm/sec)
   Column 8 - Mean v Velocity                                   (cm/sec)
   Column 9 - Variance about the u Velocity
   Column 10 - Variance about the v Velocity
   Column 11 - Covariance of u,v
   Column 12 - Number of Five Day Averages Contained within the Bin