During the accessioning process, NODC created files to include as
additional metadata for this data collection. These files include a list
of all latitude-longitude pairs for observations, graphical plot(s) of
all data location in a .ps format, and graphical plot(s) of all data
locations in a .jpg format. In some cases, graphical plot(s) of all data
locations were also stored in .tif and/or .gif formats.

The accession number assigned by NODC is depicted in each file name as
#######. The files use the following naming conventions:

#######_lonlat.txt - this file is created by extracting the longitude
and latitude values for all station locations in the data. The list of
longitude-latitude pairs is then processed to remove duplicate stations
and to reformat the values to decimal degree formats, if necessary. The
left column contains longitude values, the right column contains latitude
values.

In accordance with FGDC guidelines, North latitude and East longitude are
positive values, South latitude and West longitude are negative values.

#######_map.jpg - this JPEG file was created by plotting the values in
#######_lonlat.txt using the unix plotting software Generic Mapping
Tools (GMT).

#######_map.ps - this PostScript file was created by plotting the values in
#######_lonlat.txt using the unix plotting software Generic Mapping
Tools (GMT).

#######_map.tif - this tif file was created by plotting the values in
#######_lonlat.txt using the unix plotting software Generic Mapping
Tools (GMT).

#######_map.gif - this gif file was created by plotting the values in
#######_lonlat.txt using the unix plotting software Generic Mapping
Tools (GMT).

For more information about GMT, please see http://gmt.soest.hawaii.edu/
(last accessed on 2007-05-24).