An Overview of Shanghai VGOS Wideband VLBI System

The demand for higher precision measurements in Very Long Baseline Interferometry (VLBI) continues to grow, which drives the technical development of next generation international VLBI stations called the VLBI Global Observing System (VGOS). The Shanghai VGOS station is located in the courtyard of existing 65m radio telescope, which is 13.2 m diameter, dual-reflector systems with a ring-focus sub-reflector. It is instrumented with a broadband feed systems, which works in the 3-18Ghz range with dual-linear polarization to provide VGOS capability. The Chinese VLBI Data Acquisition System (CDAS) was designed to digitize wideband signals from receivers of radio telescopes, pack the digital samples into VDIF frames, and transmit them through 16G Ethernet interface. In this paper we present the estimated performance, focusing on the achievable system equivalent flux density (SEFD). Analysis based on measured feed data shows that SEFD of 2000 Jy can beachieved for the system.