NSA/SKYRAD/C2 - Reprocess: PIR identified as unshaded is really shaded

On 5/24/02 the Global PIR was moved from the unshaded
position on the Skyrad stand to a shaded spot on the
tracker.  It is still using the same Logger channel as
it did as an unshaded PIR even though it is now shaded.

Disregard the data description in the netcdf header.

• Downwelling Longwave Hemispheric Irradiance, Unshaded Pyrgeometer, Standard
  Deviation(down_long_hemisp_unshaded_std)
• Downwelling Longwave Hemispheric Irradiance, Unshaded Pyrgeometer, Minima(down_long_hemisp_unshaded_min)
• Downwelling Longwave Hemispheric Irradiance, Unshaded Pyrgeometer, Maxima(down_long_hemisp_unshaded_max)
• Downwelling Longwave Hemispheric Irradiance, Unshaded Pyrgeometer(down_long_hemisp_unshaded)