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lbaops:dfb3das [2009/05/28 12:14]
chris.phillips
lbaops:dfb3das [2010/12/21 15:00]
chris.phillips
Line 2: Line 2:
  
 [[.:dfb3notes | Technical Notes]] [[.:dfb3notes | Technical Notes]]
 +
 +====  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).
 +    *  16 MHz channels with 256 MHz 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)
 +    *  Giving 32/16 MHz channels with 1 GHz front end or 8/4 MHz with 256 MHz front end)
 +  *  [[http://www.vlbi.org/vdif/ | VDIF ]] packet headers 
 +  *  Packet sizes to conform to VDIF requirements, specifically an integral number of packets/sec
 +  *  Tsys monitoring
 +
 +====  Potential extra work ====
 +  *   Linear->circular conversion
 +    *  including calibration of x-y phase correction
 +  *  Single stage filter design (not the current "high resolution" filter followed by a reverse filter.
  
  
lbaops/dfb3das.txt · Last modified: 2015/12/18 16:38 (external edit)