Voyager 1 PWS full resolution uncalibrated electric field spectrum analyzer
files are organized into subdirectories by spacecraft event time.  Each sub-
directory contains all available data for a 4-month interval and is named
by a variation of PDS date convention:

  Tyymm_mm

where yy is year of century and mm_mm is one of:

  01_04 for January through April
  05_08 for May through August
  09_12 for September through December

DATASET.CAT contains High Level Catalog Template information