Local VLBI Correlation and Analysis at Geodetic Observatory Wettzell

The Geodetic Observatory Wettzell (GOW), jointly operated by the Federal Agency for Cartography and Geodesy (BKG), Germany and the Technical University of Munich, Germany is equipped with three radio telescopes for Very Long Baseline Interferometry (VLBI). Extended local correlation capabilities, however, have been missing at the Observatory so far. A computing cluster forming the GOWettzell Local Correlator (GOWL) was installed in September 2017 as well as the Distributed FX (DiFX) [Deller et al., (2011)] software correlation package and the Haystack Observatory Post processing System (HOPS) for fringe fitting and post processing of the correlated output. Data pre-processing including ambiguity resolution (if necessary) as well as the generation of the geodetic database and NGS card files is carried out with nuSolve, the final analysis is either carried out with our local processing software (LEVIKA [Schuler et al., 2018] short baseline analysis) or with the Vienna VLBI and Satellite (VieVS) software. The local correlator GOWL serves three main purposes: