1. eVLBI at Wettzell R. Dassing G. Kronschnabl

2. Wettzell is a Fundamentalstation for Geodesy (i.e. all relevant geodetic measurement systems are collocated there: VLBI, SLR, GPS, DORIS, Seismometer, Gravimeter, RingLaser) Wettzell is a Fundamentalstation for Geodesy (i.e. all relevant geodetic measurement systems are collocated there: VLBI, SLR, GPS, DORIS, Seismometer, Gravimeter, RingLaser) geodetic VLBI measurements are performed since 1983 geodetic VLBI measurements are performed since 1983 Wettzell's VLBI is part of IVS Wettzell's VLBI is part of IVS

3. Since 2004: optic fibre based, 34 Mbps connection to Wettzell Costs/year: ~ 50.000,- € („flat rate“ for uploading) eVLBI - INTERNET connection of Wettzell Wettzell http://www.dfn.de

4. Since April 2005: Int2 (Saturday, Sunday) between Wettzell and Tsukuba (Japan) is completely executed by eVLBI as a disk to disk transfer: the data stored locally on a MARK5A System The Data is get and recorded by Tsukuba 2 hours after each session automatically via FTP. 1 day after observations, they are correlated! eVLBI - Usage for VLBI  Gain of 7 - 8 days with respect to the traditional method, i.e., snail mail  One of the first scheduled eVLBI observation in IVS

5. eVLBI - Usage for VLBI This graph shows the INTERNET usage of Wettzell in June 2005. The green bars demonstrate the outgoing TCP/IP packets. The eVLBI usage can clearly be seen on Saturdays and Sundays.

6. For Wettzell, the daily INT observations are suitable candidates for eVLBI. eVLBI - Future Plans Candidates for further eVLBI based sessions: ~ 2 h~ 10 h~ 30 h155 Mbps ~ 5 h~ 30 h~ 100 h34 Mbps INT (36,68 Gbyte) R4 (~ 280 Gbyte) R1 ( ~ 1.1 Tbyte) Bandwidth (60% efficiency)

7. eVLBI - Future Plans  As soon as we can show that eVLBI is working on a regular basis, we may request for higher bandwidth  We strongly encourage the IVS to make use of eVLBI especially for INT1 Connection costs are ~ 150.000,- €/a for 155 Mbps

8. eVLBI - Summary VLBI radiotelescope at Wettzell is now connected to the INTERNET with 34 Mbps. Since April 2005, Wettzell is performing eVLBI observations for INT2 in a regular basis. The data are transfered to Tsukuba, and one day after the observations, the results of the observations are produced. We gain 7 - 8 days with eVLBI As soon as all INT observations are transfered via INTERNET, we may ask for higher bandwidth to the INTERNET.