User Tools

Site Tools


lbaops:dfb3das

This is an old revision of the document!


DFB3 for VLBI

Current State

The Parkes Pulsar backend DFB3 has a baseband mode, used with APSR. This instrument fulfills the basic requirements of a broadband VLBI backend.

  • 1 GHz or 256 MHz front end bandwidth
  • Divide by 16 filterbank (ie 64 MHz channels with 1 GHz front end)
  • Bits selectable from 1-8
  • UDP data transport with simple 24 byte timing header

Requirements

To convert to system suitable for VLBI the following changes are needed

  • More filterbank options (divide by 32 and divide by 64 have filters already designed)
  • VDIF packet headers
  • Packet sizes to conform to VDIF requirements, specifically an integral number of packets/sec
  • (Optional) Linear→circular conversion
    • including calibration of x-y phase correction
  • Tsys monitoring

Potential extra work

  • Fringe rotation
  • Complex sampling
  • “Zoom modes”, ie full channelization
lbaops/dfb3das.1243477442.txt.gz · Last modified: 2015/12/18 16:38 (external edit)