Experiences with the design and construction of wideband spectral line and pulsar instrumentation with CASPER hardware and software: The Digital Backend System

NRAO recently designed and built a universal backend system for the Shanghai Astronomical Observatory's (SHAO) 65 meter radio telescope which was constructed near the city of Shanghai, China. The machine, called the Digital Backend System (DIBAS), was created from the design of the VErsatile GBT Astronomical Spectrometer (VEGAS) by adding nine incoherent pulsar search modes and eight coherent dedispersion timing modes to complement the 29 VEGAS spectral line modes. Together these modes cover all of the anticipated science requirements for the 65 meter except for VLBI.