The UCB Seismological Laboratory currently maintains and retrieves data from 15 Ashtech Z-12 receivers. Data from these sites is collected at 30-second intervals, transmitted continuously over serial connections, collected into 24-hour raw serial files and processed daily. The serial connections to eleven sites use frame relay technology, one site (TIBB) has a direct radio link to Berkeley and three sites (SUTB, MUSB, and FARB) use a combination of radio and frame-relay technologies. We have developed software to interpret and collect the raw serial output into hourly files, which is then converted to the standard interchange RINEX format using software provided by NGS and UNAVCO. In 1997-98 we converted the last two of our sites with dial-up telemetry (HOPB and CMBB) to continuous serial telemetry.
Nine current GPS sites are co-located with broadband seismometers and Quanterra data collectors. With the support of IRIS we have developed software for the Quanterra that will allow the storage and retrieval of the continuous serial output of Ashtech and Trimble GPS receivers during and after a telemetry outage. This software has been developed and tested and hardware connections to allow its use have been made at four BSL sites. Upon Quanterra's completion of new system software, this datalogging software will be tested and submitted to UNAVCO for general public distribution.