| Date: | 2008-11-10 08:59:00 | |
| Sender: | Bernd Sierk, TIGO, BKG <sierk@mail.tigo.cl> | |
| Subject: | [SLR-Mail] No. 1731: 7405 CONL: time bias problem for CONL data | |
| Author: | Bernd Sierk, TIGO, BKG | |
| Content: | ******************************************************************************** SLR Electronic Mail 2008-11-10 08:59:00 UTC Message No. 1731 ******************************************************************************** Author: Bernd Sierk, TIGO, BKG Subject: 7405 CONL: time bias problem for CONL data Dear colleagues, I would like to notify you about a problem with SLR data measured at TIGO (7405 CONL) during last month (October 2008). Erricos Pavlis and Magdalena Kuzmizc-Cieslak have detected large time biases (of about 7 µsec) for Lageos passes measured by CONL since we resumed operation on October 8th. We tracked down the cause of this effect and found that two cables had erroneously been swapped on the time interval counter which determines the offset of our clock module wrt. GPS time. We fixed the cables and re-processed all affected data (from Oct. 8 to Oct. 29) with the correct (negative) GPS time offset. Another bug in the previously submitted NP file headers (CDP occupancy sequence number=02) was also corrected (now 03). The new NP files (with increased release flags) have been submitted last week to EDC and should be distributed to the analysis centers within the next few days. Analysts that have used the previous release of our data within the above mentioned period should redo their analysis using these new data. We of course regret this error and apologize for any inconvenience. All analyses using CONL data should take into account our new eccentricity to SRP: North [m]: -0.1996 +- 0.0007 East [m]: 0.0085 +- 0.0007 Up [m]: 1.4627 +- 0.0006 These values are valid since Oct. 8, 2008, and have changed as the telescope has been lifted (and slightly moved) during the maintenance. Our site log file has been updated accordingly. Again my apologies to analysts and special thanks to Erricos and his co-workers for helping us to identify the problem. Best regards, Bernie --------------------------------------------------- Dr. Bernd Sierk Bundesamt fuer Kartographie und Geodaesie (BKG) Observatorio TIGO Universidad de Concepcion Concepcion, Chile email: bernd.sierk@bkg.bund.de Tel: +56-41-2207035 Fax: +56-41-2207031 WWW: www.tigo.cl -------------------------------------------------- From: sierk@mail.tigo.cl ******************************************************************************** |