This directory contains FITS files at a 2-minute cadence
which have been produced by processing 4Kx4K AIA level 1
images to level 1.5, then reducing them to 1024x1024 2.4
arc-sec pixels by summing each non NaN valued pixel in
the 4x4 pixel cell and dividing by the number of non NaN
valued pixels. The pixel value units are DN per original
0.6 arc-sec pixel. The files are stored in a year, month,
day, hour, and filename directory heirarchy. These images
are produced approximately 7 days after T_OBS since they
are derived from definitive level 1 data. The image_times
and image_times.json provide the time for the most recent
(current final) synoptic file.

As a convenience, similar NRT images are produced at a
3-minute cadence in the synoptic/nrt directory hierarchy
with a 15 to 20 minute latency from T_OBS. Because of
various latencies and parallelisms in the level 0 and
level 1 NRT pipelines, data are occasionally produced
out of time order. Gaps in NRT AIA synoptic data do not
get filled. The nrt directory has image_times and
image_times.json files for the NRT synoptic images.

The mostrecent directory has the most recent NRT synoptic
image for each wavelength. These images have fixed file
names (no date-time in file name). The file named image_times
in the mostrecent directory has the time for the most
recent file in that directory.