All of the drifter data in this dataset was collected by "optical" drifters. There are a number of different studies, research efforts, and geographical areas covered by the information in this dataset. The location variable contains some information with regards to the geographical area of the data.
For More Detailed Information on this dataset please goto:
The Oregon Remote Sensing Ocean Optics (ORSOO) home page
or to
The data at the above site is organized by geographical location, so you might use the value of the location variable, along with the fact that this is optical drifter data as keys to getting useful information from the site.