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Automated
Data Handling within the IRIS DMS
The
IRIS DMS has been in the process of shifting data archiving from
physical tapes to electronic transfer for a few years. Our first
major effort to receive data electronically began with the installation
of the Frame Relay Circuit between the US National Data Center for
the CTBT at Patrick Air Force Base, Florida, and the IRIS DMC. Data
from several Air Force stations and arrays have been sent to the
IRIS DMC since May, 1998. Data from AFTAC are sent using CD-1 protocol
and received using the Antelope software from Boulder
Real Time Technologies (BRTT). The data are received, converted
to miniSEED format and archived automatically at the DMC. These
data are available using the same suite of data
request tools as other data at the DMC. Data from Patrick AFB
are available using network code IM. Unfortunately at this time
only stations on US soil are included in the data stream from Patrick
AFB.
To
reduce the problems associated with data delivery by tape from the
Data Collection Centers to the IRIS DMC, the DMS installed Frame
Relay Communication Circuits between the DMC in Seattle and the
IRIS/USGS DCC
in Albuquerque and the IRIS/IDA
DCC in San Diego. At the present time, data from the two GSN
DCCs are routinely transferred to the DMC using a system built around
ftp. As with the data from Patrick Air Force Base, data that arrive
at the DMC from the DCCs are automatically archived without intervention
by the operator. We have found that the reliability of the electronic
transfer of GSN data has improved the reliability of data delivery
as well as allowing the number of technicians at the DMC and the
DCCs to actually decrease through attrition.
The
IRIS DMC is involved in a fairly ambitious effort to significantly
increase the amount of data that the DMC receives in real time or
near-real time. There are two primary systems that have been developed
recently (see companion article) that the
DMC intends to exploit to receive data in near-real time. The Antelope
System from BRTT was initially installed to receive data from the
Air Force seismic stations. Concurrently the USGS has developed
the Earthworm system. Both systems are capable of real time transmission
of data. The DMC is either presently receiving or shortly will be
receiving data from the following networks from these two systems:
| Data
Source |
Network
Code
|
Number
of Stations
|
Real
Time System
|
| Patrick
Air Force Base |
IM
|
50
|
Antelope
|
| IRIS/USGS
GSN via LISS |
IU,
IC
|
37
|
Antelope
|
| IRIS/IDA
GSN via NRTS |
II
|
13
|
Antelope
|
| PASSCAL
BB Array |
XF-2000
|
73
|
Antelope
|
| Kyrghyzian
Array |
KN
|
14
|
Antelope
|
| Kazakh
Network |
KZ
|
37
|
Antelope
|
| Anza
Network |
AZ
|
58
|
Antelope
|
| TERRAscope |
CI
|
38
|
Antelope
|
| Alaska
Network |
AK
|
1
|
Antelope
|
| Northern
Nevada |
NN
|
11
|
Antelope
|
|
Lamont-Doherty Nets |
LD
|
2
|
Antelope
|
| US
National Network |
US,LB
|
45
|
Earthworm
|
|
University of Washington |
UW
|
266
|
Earthworm
|
| University
of Utah |
UU
|
124
|
Earthworm
|
| New
England Nets (MIT) |
NE
|
*
|
Earthworm
|
| New
Madrid |
NM
|
*
|
Earthworm
|
| Southeastern
US |
SE
|
*
|
Earthworm
|
| Memphis
University Nets |
ET
|
*
|
Earthworm
|
| Delaware
Geological Survey |
DG
|
*
|
Earthworm
|
* Data
not yet flowing
At
the present time the staff at the DMC are working on systems that
will eventually replace many elements of the SPYDER® system in building
data sets in near-real time from the data that we are receiving
electronically. (See
the article in the previous Electronic Newsletter). Additionally
our plan is to begin relying on data received by electronic methods
to automatically add to any of the new
FARM data sets. Our goal is to develop techniques that automatically
ingest data in real time, or by delayed methods such as ftp, from
all sources of data at the DMC. Data will be made available through
automatic methods and not rely on the intervention of DMC technicians
in most cases.
By
shifting to electronic data handling, the DMS intends to increase
the amount of data it handles, provide it more reliably and more
timely, without increasing operations staff. So far this strategy
to improve efficiency has been working well within the IRIS Data
Management System.
Submitted
by Tim Ahern
For more information or comments contact
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