New Observing Modes for the DBBC3

Paper i proceeding, 2019

The DBBC3 was further enhanced by introducing new modes. Three different firmwares have recently been implemented for observing: Direct Sampling Conversion (DSC), arbitrary selection of bands (OCT), and Digital Down Conversion (DDC). These modes cover all the requirements of astronomical, VGOS, and legacy geodetic VLBI for the time being and the immediate future. In addition, the DBBC3 offers unsurpassed compatibility to the relatively large number of other existing VLBI backends. A number of test observations were performed in the last months to achieve the best performance of the VGOS modes, and similar tests are planned for the EVN network. At the same time the DBBC3 is an important platform for additional new modes to be implemented for the BRAND receiver. Several DBBC3 systems are deployed in the field and more are under construction, with the number of 4-GHz bands ranging from two up to eight with resulting output data rates from 32 Gbps to 128 Gbps.