Cristina Garcia Miro
Type of contribution: oral
Session: 2

VLBI Data Acquisition Terminal modernization at the Deep Space Network

Cristina García-Miró, Ingeniería y Servicios Aeroespaciales S.A., INTA/NASA, Madrid Deep Space Communications Complex Stephen P. Rogstad, Jet Propulsion Laboratory, California Institute of Technology/NASA Robert Navarro, Jet Propulsion Laboratory, California Institute of Technology/NASA John Eric Clark, Jet Propulsion Laboratory, California Institute of Technology/NASA Charles J. Na

The Deep Space Network is replacing the aging MarkIV Data Acquisition Terminal (DAT) with a digital backend: the Deep Space Communications Complex VLBI Processor (DVP). It is based on the Wideband VLBI Science Receiver (WVSR), a custom made open-loop digital receiver developed in JPL that is successfully supporting differential-VLBI for spacecraft navigation (DDOR) and other radio astronomy applications: Earth orientation parameters determination, astrometry, spectroscopy observations, etc. The new acquisition terminal has inherited from the WVSR the IF digitizer module, the firmware architecture and monitor and control software. Among the new features it improves considerably the recording rate providing at least 1 Gbps with the goal of achieving 4 Gbps, it uses a CASPER ROACH board for real-time Digital Signal Processing and channelization and streams the data into a Mark5C recorder. This contribution describes in detail the DVP in the context of similar digital developments (RDBE, DBBC, etc.). As the new backend will not use the standard Field System environment to perform the VLBI observations, efforts are under way to make it compatible with the correlators, providing monitor and calibration data in the appropriate format. Lately an important effort has been made in the DSN towards automation of the VLBI data acquisition using the Automation Language for Managing DSN Operations (ALMO). The automation process will be adapted for the new DAT.