The Long Baseline Array Data Acquisition System (LBA DAS) is a digital sampler and filter-bank developed by the AT Electronics Group in the 1990s, chiefly by Dick Ferris and Martin Oestreich.

The primary application of the DAS was for the Long Baseline array, for which it has been the standard filter-bank/sampler for more than 20 years, being deployed to Mt Pleasant Observatory in Hobart, Ceduna (SA), Tidbinbilla (ACT) and Hartebeesthoek (South Africa) as well as the the three ATNF telescopes in NSW. Initially the DAS was used in conjunction with the S2 tape-based VLBI recorder developed by STSI in Canada. The LBA retired its S2 fleet in 2007 and switched to recording direct to computer disks, with the DAS providing the input to a VSI interface to the disks.

The DAS units at Parkes were also used to record pulsar data in voltage format to perform coherent de-dispersion (including of the millisecond pulsar J0437-4715) and for spectral-line observations of celestial masers, making use of the excellent DAS filter characteristics.

Documentation

Documentation – an unannotated collection of technical documents, DAS profiles and other files

Pictures

Complete LBA_DAS System

N3 HiRes Sampler – Analog Board

N3 HiRes Sampler – Image Filter

N3 Hi Res Sampler – Close up of AD chip

N3 Digital Filter – Band Splitter Board

N3 Digital Filter – Fine Tuner Board

N4 Power Supply

John Reynolds – December 2024