For each station and data year, the data files are contained in two formats
under the directories "csv_format" and "sensor_format".

The "csv_format" data files are in the comma separated values with comments
at the beginning of each file describing the data format.  These files can
be directly uploaded into a spreadsheet.

The "sensor_format" data files are in the format as output from the sensor,
typically text files.  Each directory contains a README file describing the
format for data files in that directory.