New Observing Modes for the DBBC3

The DBBC3 was further enhanced by introducing\ua0new modes. Three different firmwares have\ua0recently been implemented for observing: Direct Sampling\ua0Conversion (DSC), arbitrary selection of bands\ua0(OCT), and Digital Down Conversion (DDC). These\ua0modes cover all the requirements of astronomical,\ua0VGOS, and legacy geodetic VLBI for the time being\ua0and the immediate future. In addition, the DBBC3\ua0offers unsurpassed compatibility to the relatively large\ua0number of other existing VLBI backends. A number\ua0of test observations were performed in the last months\ua0to achieve the best performance of the VGOS modes,\ua0and similar tests are planned for the EVN network. At\ua0the same time the DBBC3 is an important platform\ua0for additional new modes to be implemented for\ua0the BRAND receiver. Several DBBC3 systems are\ua0deployed in the field and more are under construction,\ua0with the number of 4-GHz bands ranging from two up\ua0to eight with resulting output data rates from 32 Gbps\ua0to 128 Gbps

Onsala Space Observatory – IVS Technology Development Center Activities during 2017–2018

We give a brief overview of the technical development related to geodetic VLBI done during 2017 and 2018 at the Onsala Space Observatory

Status of the Onsala Twin Telescopes – Two Years After the Inauguration

We give a brief overview on the status of\ua0the Onsala twin telescopes (OTT), two years after their\ua0inauguration. The dierent components of the VGOS\ua0systems are briefly described, and the development towards\ua0routine operations

Status of the Onsala Twin Telescopes – One Year After the Inauguration

We briefly describe the status of the Onsala\ua0twin telescopes and the experience gained since the official\ua0inauguration in May 2017

DBBC3 Towards the BRAND EVN Receiver

The DBBC3 is a flexible VLBI backend and\ua0environment that supports a wide range of observational\ua0needs via a suite of FPGA firmware types. The\ua0hardware can sample up to eight 4 GHz-wide baseband\ua0signals and convert to digital streams over multiple\ua010GE links on fibre. The development team has an ongoing\ua0development programme that has enhanced existing\ua0modes and introduced new desired modes as user\ua0requirements evolve. Three dierent firmware types for\ua0observing have been implemented which will be briefly\ua0summarised: Direct Sampling Conversion (DSC), arbitrary\ua0selection of bands (OCT), Digital Down Conversion\ua0(DDC). These modes cover all the requirements\ua0of astronomical, VGOS and legacy geodetic VLBI of\ua0the present, but also of the near future. At the same\ua0time the DBBC3 is an important platform for additional\ua0new modes to be implemented for the BRAND\ua0receiver. This paper describes the use of the DBBC3\ua0for the receiver development, pointing out which element\ua0in the current DBBC3 structure will be part of\ua0the BRAND receiver in order to simplify its introduction\ua0into the existing VLBI environment at telescopes\ua0with a DBBC3 backend

Onsala Space Observatory – IVS Technology Development Center

This report briefly describes the technical development relevant for geodetic/astrometric VLBI done during 2010 at the Onsala Space Observatory

Onsala Space Observatory – IVS Technology Development Center

We report 2012 activities and plans for 2013

DBBC3 — The new wide-band backend for VLBI

The DBBC3 VLBI digital backend is the successor of the most widely adapted digital VLBI backend DBBC2. The DBBC3 offers much wider bandwidth and integrated Ethernet output. Three different firmwares for observing have been implemented until now: Direct Sampling Conversion (DSC), arbitrary selection of bands (OCT), and Digital Down Conversion (DDC). These modes cover all the requirements of the astronomical, VGOS and legacy geodetic VLBI of today, but also of the near future. In addition the DBBC3 offers unsurpassed compatibility to the relatively large number of other existing VLBI backends. A number of DBBC3 systems have been deployed and more are currently under construction, with the number of 4 GHz bands ranging from 2 up to 8 with resulting typical output data-rates from 32 Gbps to 128 Gbps. Laboratory and field tests have been performed