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Organization
of Data Holdings at the IRIS DMC
Data
flows into the DMC from a variety of sources and are archived. This
article doesn't intend to describe the process of archiving but,
instead, outline the nature of how our various filesystems are managed
and updated. It is helpful to users to understand the fundamental
differences in the various data products which are now on-line and
readily available in near-real time. This can be useful in determining
which data are appropriate for their specific application. (For
more about how data requests are handled, see this previous DMS
Newsletter article.)
| Data |
Where
is the data stored? |
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SEED
Data coming through the BUD system (details)
lives on its own machine. (Some timeseries data can eventually
be migrated into the permanent archive.) This real time data
can be accessed through the BUD
Web interface until it is quality controlled and moved
onto the near-line system where it is accessed using any of
the DMS's standard request tools. (Some BUD data receives
no further QC and can be archived "as is.")
NOTE:
SEED data that comes into the DMC on tape (not through the
BUD) goes through a similar process as the electronic transfers
but the archiving process is not automated.
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SPYDER®
data are managed separately and it stays separate until the
data have been replaced by quality-controlled data and converted
to FARM volumes. |
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FARM
products are created from quality controlled data that is in
the near-line (tape-based) archive and stored with the SPYDER®
data, eventually replacing the SPYDER® products. |
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Assembled
data sets are non-SEED formatted data that come to the DMC on
tape (or some other media). Because they are not in SEED format,
the timeseries information cannot be loaded into the near-line
archive. Instead, a tape image is stored on the archive system.
This image can be copied back to a tape, a CD, or to an FTP
directory for pickup. (The majority of these data are active-source
PASSCAL experiments or special aftershock surveys, for example.) |
For more information or comments contact 
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