1 / 1

Access to Nyquist-sampled voltages from tied-array beams:

Access to Nyquist-sampled voltages from tied-array beams: Four or more tied-array beams required, at any point in the full field of view; Tied-array inputs should be delayed to a common point and fringe-rotated;

arnie
Télécharger la présentation

Access to Nyquist-sampled voltages from tied-array beams:

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Access to Nyquist-sampled voltages from tied-array beams: • Four or more tied-array beams required, at any point in the full field of view; • Tied-array inputs should be delayed to a common point and fringe-rotated; • Full flexibility as to which antennas are used in the individual tied-array beams; • Ability to re-phase tied-array regularly. • Circular polarisations required (minimum leakage). • Channelised voltages acceptable at 1, 2, 4, 8, 16, 32, 64, 128 and 256 MHz bandwidths: • Dual polarisation; • Up to 16 channels selectable for recording (contiguous or non-contiguous); • Tunable over the instantaneous bandwidth; • 2, 4, or 8 bit samples. Real voltages? • Continuous data streams, made available to recording system on 10 Gbps ethernet: • VLBI Data Interchange Format (VDIF) used for framing the data. • Tsys calibration (every ~10 sconds), phase stable system (phase returns after frequency/source changes), on-source logging: • Hydrogen maser preferred for time keeping. • Maximum data rate of 32, 768 Mbps. Transferred to recording system in Geraldton via fibre. • Hardware in Geraldton ~5 kW initially and ~20 kW in long term; • Possible hardware on site initially if single pixel feed is adopted; • Final processing of data at LBA correlation facility at Curtin (ship disks initially and network • transfer in long term). • Limited commensal observing possibilities (fast transients and deep continuum survey). VLBI requirements for ASKAP ASKAP f2f April 15, 2009Prof. Steven Tingay (on behalf of the ASKAP VLBI team)

More Related