The MODIS Atmosphere Daily Global Product is produced at the MODAPS facility at the
NASA Goddard Space Flight Center.
MODAPS will produce 100% of the MODIS Atmosphere Daily Global Product.
The data volume will be a single HDF file of nearly 500 MB per day.
These rules apply to PGE56, the daily executable.
At the time all 36 (5-degree) tile file daily inputs are expected,
run PGE56 only if all tile files are present.
Otherwise, wait 24 hours, then run if at least one
tile file is present.