[IGSMAIL-4817]: GPS Seamless Archive (GSAC)

[Yehuda Bock]

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IGS Electronic Mail      30 Jan 09:48:08 PST 2004      Message Number 4817
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Author: Yehuda Bock, Michael Scharber, Brent Gilmore

We would like to announce that SOPAC has completed development of 
first-generation GSAC software for the UNAVCO Community. SOPAC's 
final report can be accessed at 
http://www.unavco.org/facility/data/gsac/reports/GSAC_FinalReport.pdf 
and http://gsac.ucsd.edu/docs/GSAC_FinalReport.pdf.

The following is an announcement that was prepared by the GSAC Working Group:

Single-portal access to the continuous and campaign data held by the
NASA Crustal Dynamics Data Information Center (CDDIS), Northern California
Earthquake Data Center (NCEDC), Pacific Northwest GPS Array (PANGA),
Southern California Earthquake Center (SCEC), Scripps Orbit and Permanent
Array Center (SOPAC), and UNAVCO's Boulder Facility is now available 
through the GPS Seamless Archive Centers (GSAC). Together these 
archives hold over 2 million RINEX files collected for over 10,000 
monuments, including a nearly complete set of data collected between 
1986 and 2003 for the global network and western North America, and a 
significant quantity of data collected by U.S. scientists in other 
tectonically active regions of the world.   

At present there are two GSAC access points ("Retailers") for the 
data in the participating archives ("Wholesalers"): SOPAC ( 
http://gsac.ucsd.edu) and UNAVCO 
(http://www.unavco.org/facility/data/gsac/gsac.html). Both sites 
provide a web interface for locating data using spatial and temporal 
constraints. In addition, a map interface available thus far only at 
the SOPAC site will be useful to many users. Once you have identified 
useful data, you can generate download commands (for on-line data) or 
email requests (for data off line or not yet publicly available) 
using a command-line client which can be downloaded from either web 
site. The current holdings consist primarily of monument records and 
RINEX files, but we envision the inclusion of SINEX, site logs, and 
other forms of geodetic data.
   
The goals of GSAC are to aid current and future research by providing 
a convenient way for scientists to discover, and organizations to 
advertise, useful data holdings; by supplying retrieval commands in 
standard formats; and by using the GSAC structure to encourage 
individual investigators to submit their data to permanent archives 
to assure long term preservation and access.  For these goals to be 
fully met, the GSAC needs to recruit new Wholesalers  If you maintain 
an archive of geodetic GPS data, whether public or nonpublic, 
continuous or campaign, please consider participating as a 
Wholesaler.  The data files will be indexed in the GSAC and can 
therefore be easily located by scientists worldwide.  If you 
currently operate a public archive of GPS data, please consider 
acting as a Retailer to add another point of access, particularly if 
your agency can offer unique and efficient approaches to searching 
the Wholesaler database or is interested in providing a GSAC 
interface in languages other than English.

The SOPAC and UNAVCO GSAC web sites provide more information about 
the history, protocols, useful software, and contact information.

-- 
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Yehuda Bock		e-mail: ybock at ucsd.edu
Research Geodesist	Phone:  (858) 534-5292
& Senior Lecturer	Fax:    (858) 534-9873
			WWW:    http://sopac.ucsd.edu/; http://csrc.ucsd.edu/

Director, Scripps Orbit and Permanent Array Center (SOPAC)
Director, California Spatial Reference Center (CSRC)

Address:
University of California San Diego
Institute of Geophysics and Planetary Physics
9500 Gilman Drive  DEPT 0225
La Jolla, CA 92093-0225

FedEx Address:
Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics
Scripps Institution of Oceanography
8785 Biological Grade, Room 4208
La Jolla, CA 92037
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