SKAMP Square Kilometre Array Molonglo Prototype

Supporting Institutions  University of Sydney  Argus Technologies  ATNF  ICT Centre

SKAMP Team  Bevan Jones  Andrew Parfitt  John Kot  Peter Liversidge  Daniel Mitchell  Adrian Blake  Anne Green  Duncan Campbell-Wilson  John Bunton  Mike Kesteven  Tim Adams  Martin Leung  Sergey Vinagradov School of Physics, University of Sydney Argus Technologies, Sydney ICT Centre, CSIRO Australia Telescope National Facility, CSIRO

SKAMP Specifications  Multibeaming  Wide instantaneous field of view  Digital beamforming  Wide-band FX correlator (2048 channels)  Frequency and pointing agility Collecting area = 1% of SKA (i.e. equivalent to 1 SKA station)  Line feed GHz >100 MHz instant BW  Cylindrical antenna prototype  RFI mitigation strategies - adaptive noise cancellation

SKAMP Project Stage I: Continuum Operation  New IF Samplers  Digital delay lines  Fringe tracking  Continuum correlator (96 station; 4 MHz) Stage II: Spectral Line Operation  New LO  New IF distribution  2048 channel polyphase filter/antenna;  Spectral line cross-correlator engine (50 MHz BW) Stage III: Wide Band Operation  Wide band feed ( MHz)  RF beamformers distributed along the cylinder  New front-end  Digital beamformer + increased correlator BW

SKAMP Development Groups  Antenna/Linefeed  Data Acquisition & Beamforming  Correlator  Signal Processing A x B

Antenna/Linefeed Progress Initial prototyping and simulation has begun for possible linefeed designs Currently being investigated is a wideband dipole antenna element  A three element array has been constructed and tested  Several multi element arrays have been simulated A x B

Prototype antenna design

Simulation: Normalised Amplitude  Eight Element Array  Optimal choice of spacing  High polarisation purity (-24 dB)  Low level of sidelobes

Simulation: X-Polar Pattern  Eight Element Array  Optimal choice of spacing  High polarisation purity (-24 dB)  Low level of sidelobes

Data Acquisition & Beam-forming Progress 100 x ADC boards manufactured & ready to install Digital delay & phase-tracking board currently being manufactured First fringes obtained Stage II – samplers, IF signal transport and beamformers in design A x B

ADC Production & Testing

First Fringes

Correlator Progress Correlator design complete & PCB is current being manufactured/populated Testing & debugging will commence early July Lab for testing established at USYD Stage II – spectral line correlator design being revised; several options for polyphase filterbank A x B

Signal Processing Progress SKAMP I interface built and installed  Controlled acquisition of telescope parameters, wide field position and visibilities every second  From ephemeris package, computed delay, phase and phase rates. Also calculation of telescope tilt and meridian distance.  Distribution of information to delay and phase control units  Imminent completion of data visibility formatting and archiving A x B

Summary Stage I:  Commissioning August – December 2004 Stage II:  Update design matrix Stage III:  Commissioning eight element prototype  Simulation of centre fed finite cylinder