Delivered-To: igs-dcwg@igscb.jpl.nasa.gov Date: Thu, 18 Mar 2004 09:52:15 -0500 (EST) From: Carey Noll Reply-To: Carey Noll To: IGS DCWG Mail Subject: [IGS-DCWG-22] Summary of IGS DCWG Meeting in Berne Message-ID: Sender: owner-igs-dcwg Precedence: bulk ****************************************************************************** IGS-DCWG Mail 18 Mar 06:52:18 PST 2004 Message Number 22 ****************************************************************************** Author: Carey Noll/CDDIS We had a very busy 1.5 hour meeting in Berne on March 2. I will attempt to summarize our discussions and plans. We covered two topics during the meeting: 1. Long-term archive of raw data. Yehuda Bock reported that SIO keeps raw data on-line and users can download these data for reprocessing anytime. However, others pointed out that in general raw data can be difficult for users to handle since metadata (e.g., antenna height, etc.) need to be applied properly. It was therefore recommended that operational data centers keep the raw data, rather than archiving them at a regional or global data center level. Archiving of raw data is useful for two major reasons. Errors in RINEX conversion have occured and require the raw data to correct. Since a majority of sites provide data to the IGS at a 30-second sampling rate, if higher rate data are required (i.e., to study past or silent earthquakes), raw data would need to be used. Recommendation: Operational data centers should archive raw data indefinately. These data do not need to be on-line or accessible to IGS users but should be available upon request. 2. Handling of replacement data. This topic addresses how to archive replacement, retracted, or data transmitted with a large (e.g., months) delay. We need to indentify what type of problem/change requires a replacement. When a replacement is issued for a previously-released data set, the archive and the end user need to be notified. We also need to have a way to distinquish the old version of the data from the new version (using a time tag/size of file/md5sum/etc.). We came up with several possible solutions: a. Establish a new email list and have ODCs issue emails to this list using a prescribed template. b. When a replacement is made, archive the old file in an old subdirectory (could be within the daily directories) at the RDCs and GDCs. Use an email mailing list as in a) as well. c. Send a signal/flag file (e.g., SSSSDDDD0.msg) with a replacement data set that is archived with the data; presence of this file would indicate to the archive and the user that a new replacement file has been issued. Use an email mailing list as in a) as well. In all cases, an an on-line listing of data revisions with the replacement information should be maintained. We all agreed that this was a difficult topic. UNAVCO will be looking into LDM more closely in support of PBO and this effort may be of use to the IGS data flow in the future. Recommendation: Circulate possible solutions to the DCWG and decide on a plan for handling the archive of replacement data. I would like to get the opinion of working group members on these two topics and generate some more "formal" recommendations for our group that can be tested in the near future. Regards, Carey. +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ Ms. Carey Noll Manager, Crustal Dynamics Data Information System (CDDIS) Secretary, ILRS Central Bureau Code 922 E-mail: Carey.E.Noll@nasa.gov NASA GSFC Voice: (301) 614-6542 Greenbelt, MD 20771 Fax: (301) 614-6099 USA WWW: http://cddisa.gsfc.nasa.gov/cddis_welcome.html +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+