The SKA Molonglo Prototype (SKAMP)
Prototyping SKA Technologies at the Molonglo Radio Telescope
Next SKAMP Project Meeting - Wednesday 2nd December 2009 - ATNF, Marsfield
The Square Kilometre Array (SKA) is an international project to build a radio telescope which will be 100 times more sensitive than any existing radio telescope with about one million square metres of collecting area. In order to design and build this new generation radio telescope major new technology is needed. SKAMP is a joint CSIRO/University of Sydney project, largely funded through the Australian Government's Major National Research Facilities (MNRF) program, to develop and test new technology for the SKA.
The telescope at Molonglo will be equipped with new wide-band feeds, low-noise amplifiers, digital filterbanks and FX correlator, and demonstrate 300-1420 MHz continuous frequency coverage and multibeam mode operation. This will allow us to develop new capabilites for low-frequency radio astronomy in Australia, enabling exploration of the distant universe.
Collaboration at CSIRO is with engineering and science teams at the Australia Telescope National Facility (ATNF) and the ICT division of Wireless Technology. This collaboration is integral to the success of the project; the final design and implementation will be jointly achieved.
A Powerpoint overview of the Molonglo Observatory and the SKAMP projects available.
The following image illustrates the three key stages to the SKAMP project.
Specifications of SKAMP
| Field of View | 2.2 deg FWHM EW x 2.2 cosec |dec| deg FWHM NS approx at 843MHz, i.e. the FoV stretches NS as declination moves from the pole towards the equator. |
| System Temperature | 80K (Tsky=10K, LNA T=20K, Feed Loss= 10K, Ground spill = 10K, Mesh leak = 15K, Tmatch = 15K) |
| Geometric Area | 11.6m * 1556m = 18,000sq m |
| Illumination Efficiency | .5 (Mesh efficiency ~ .95, MD projection efficiency, unity at SCP then efficiency will go up and down ~ .5, MD alignment efficiency ~ .95) |
| Effective Area | .45 * 18,000 = 8100 sq m (this will range from a max of 8100 at the south pole to around half this at dec -30) |
| Elevation Limit | 35deg (North South), 30deg (East West) |
| Observing Frequency | SKAMP II - 843MHz. SKAMP III - 700-1400 MHz in 100 MHz bands. |
| Noise in 12 hr observation as: | (a) A Continuum Correlator: 0.2 mJy rms(SKAMP 2 estimated, based on BW of 10MHz effective due to RFI); 0.1 mJy rms (SKAMP 3 estimated). Note that for sources >0.8mJy the source density is 130/deg^2, corresponding to 50 beam areas/source, close to the confusion limit.
|
| Angular resolution | 43 x 43 cosec |dec| arc seconds |
| Bandwidth | SKAMP II - 30MHz (nominal, 50% response; limited by bandwidth of ring antennas). SKAMP III - 93.75MHz |
| Data Rate | .75Gb/s, 32 sec dump time, corresponding to 337 GB/hr. |
| # of channels | 6480 channels (14.4kHz channel spacing; 5.1 km/s at 843 MHz) obtained by averaging over 4 channels of 3.61 kHz. |
| # of Receivers | SKAMP II - 352 (88*4). SKAMP III - 176 for each polarization. |
| # of Polarizations | SKAMP II - 1 (elliptical right circular polarization). SKAMP III - 2 (linear) |
| Operational Modes | Limited continuum observations (1,2,4,8,10 MHz, spectral line at 15MHz); 12 hour observation. |
Project Components
Frontend & Antennas:
- October 2009 - Version 2 of the Receiver FPGA board and Down Converter complete and undergoing testing.
- March 2009 - Molonglo team currently working on the Receiver; new TCC; RFI shielding; and much more - updates to come.
- Information on SKAMP Antennas and frontend prior to 2007 can be found here
SKAMP Continuum Correlator and Digital Systems:
- November 2009 - Darshan Thakkar, Duncan Campbell-Wilson and Ludi de Souza are helping with the end-to-end testing and integration of the MWA digital system at Curtin.
- March 2009 - Boards are ready for production. Correlator firmware is currently under development - updates to come.
- Project status prior to 2007 can be found following the link below
Data Acquisition and Software Pipeline:
- Data pipeline software now available for testing.
SKAMP III - The RPT, with meshing complete, is now up on its stand and secured in position. One Antenna module has been installed - as pictured.
Latest SKAMP news
SKAMP Rx
Oct 2009: Duncan Campbell-Wilson and Darshan Thakkar have been making good progress on the development of the receiver and downconverter boards for the SKAMP front end. Version 2 of the receiver board (Rx V2) has been received and FPGA placed. The installed local oscillator (LO) distribution boards are now being tested in conjunction with the Rx V2. The primary objective of this testing will be to produce reliable clock and LO signals with minimum distortion, noise and mixing products.
Bit Error Rate Tests on the Receiver-PFB interface have been carried out successfully, and complete path testing will soon follow. Advanced diagnostics are being added to the Receiver Firmware and Software for sophisticated remote debugging.
Version 2 of the Down Converter prototype has also been received. It has been powered up and is currently being tested.
FPGA Receiver Board. Both photos courtesy of the Molonglo Observatory, USYD
FPGA Rx board and Down Converter boards within the Rx Box. The brass boxes over the Down Converter minimize mutual coupling between input channels.
Science with SKAMP: Widefield Spectroscopy of the Southern Radio Sky - September 2009
The University of Sydney hosted a science workshop at the Molonglo Observatory on 16th to 17th September 2009. "Science with SKAMP: Widefield Spectroscopy of the Southern Radio Sky" provided the opportunity to discuss and develop science plans for SKAMP. Invited speakers and other details are available on the workshop WWW page).
More information and presentations to follow.
Click here to view larger image.
Science with SKAMP workshop delegates at the Molonglo Radio Observatory
SKAMP & MWA teams at ATNF, CSIRO - Aug/Sept 2009
Darshan Thakkar, from the Molonglo Observatory and Russ McWhirter, from the MIT Haystack Observatory travelled to Sydney early August to begin a period of intensive firmware development for the SKAMP and MWA projects at ATNF, CSIRO. Working closely with Ludi de Souza and John Bunton from ATNF, Darshan and Russ have been finalising and testing the PFB firmware as well as working with Bart Kincaid (MIT Haystack) to complete the MWA 32T correlator firmware. A full set of boards for the SKAMP system, including receiver was set up at ATNF for testing.
During the final week, the firmware teams from ATNF, MIT, The University of Sydney and RRI travelled to Curtin Univ to carry out the hardware integration activities. Testing involved ensuring data integrity and functional testing from the antennas, beamformers, MWA receiver boards (ADFB and AGFO), fine PFB board, correlator board through to the Real Time Computer that process the signals into an image cube. Hardware was transported from MIT for integration, and some damage was caused to the card cages and correlator. However, these were quickly rectified and end-to-end testing progressed well throughout the week.
Significant progress has also been made on the SKAMP receiver over the last few weeks. Duncan Campbell-Wilson successfully sent a sky signal through the receiver to the PFB to produce a spectrum.
Integration team at Curtin. Front: Srivani KS (RRI), Darshan Thakkar (USYD), Ludi de Souza (ATNF), Prabu T (RRI); Back: Wayne Arcus (Curtin), Russ McWhirter (MIT), David Emrich (Curtin)
Molonglo Renovations - May 2009
During May/June 2009, the main building at the Molonglo observatory underwent some major renovation in preparation for SKAMP II, in particular to improve the RFI shielding required for the project. The control room has been partitioned to create a new RFI shielded, sound-proof room for the SKAMP II digital system. This room is almost complete and only requires sound-proofing.
SKAMP II needs to be insulated from noise up to 50DB. After several discussions, multi-layer approach to RFI shielding was considered the most effective and cost-efficient way forward:
- Double mesh on the telescope
- Mesh over the outside of the building which extends underground
- Metal cladding over the southern part of the building
- Shielded SKAMP II room within the control room.
The new partitioned room for SKAMP II - not quite complete.
Asbestos being removed in preparation for re-cladding
SKAMP Project Team - 2009 Meetings Schedule from May
- Wednesday 27th May 2009 - ATNF, Marsfield
- Friday 26th June 2009 - School of Physics, USYD
- Wednesday 29th July 2009 - ATNF, Marsfield
- Friday 28th August 2009 - School of Physics, USYD
- 16th to 17th September 2009 - Science with SKAMP workshop, Molonglo Observatory
Please note: Venue may change if a site visit is possible.
Farewell to the TCC Console
In January 2009, Molonglo bid farewell to the famous telescope control computer console which has been a much admired fixture since the 1960s. The Correlator and Digital Systems for SKAMP will be installed within ACTA cages in the control room at Molonglo, which will need their own sound-proof room. This leaves little room for the TCC console.
The original TCC console at Molonglo
TCC now installed within these racks
SKAMP Digital Systems
The Digital System for SKAMP has just been assessed via the Production Readiness Review and will be going into production mid-2009. CSIRO, through John Bunton, and MIT Haystack, through Dr Roger Cappallo, have developed the architectural design of the Digital System.
The Digital System for SKAMP is made up of the following boards which will all be housed within ACTA cages at Molonglo:
- Correlator Board x 24: Firmware is currently under development at MIT, Haystack
- Polyphase Filterbank Board (PFB) x 24: Firmware developed by Ludi de Souza and is now complete.
- Slot-1 Controller x 4
- Correlator RTM x 24
- Polyphase Filterbank RTM x 24
Correlator board prototype (August 2008)
PFB board prototype (August 2008)
- Correlator and PFB photos courtesy of CSIRO.
NEW RELEASE - Nov 2008 - SKAMP Data Pipeline Software. Version 1.11a of this new software created by Michael Birchall is now available for testing.
Prior to 2008
SKAMP - Archive of Project Updates. Below - archives in brief:
2007
- SKAMP I - First 12-hour image!
2006
- SKAMP team contracted Domain-42 Pty. Ltd. to assist with the design of the spectral line correlator (SKAMP II).
- Xilinx donates over $30,000 worth of FPGAs.
- Power replaced and rewired at Molonglo Observatory in readiness for new correlator.
- Good progress on design of new wideband receiver and digitiser required for SKAMP II.
- Argus Technology support and fund PhD student to develop dual polarised line feed for SKAMP III.
News of other SKA-related projects in Australia and New Zealand
See the latest Australian SKA Newsletter.
Recent meetings and events
News and details of international meetings can be found on the International SKA webpage.
SKAMP Documentation
SKAMP Reports, Publications, Presentations and Documentation.
Photos
SKAMP People
- Anne Green (USyd Project Director)
- Debra Gooley (SKAMP Project Coordinator)
- Bryan Gaensler (Federation Fellow)
- Michael Kesteven (Project Scientist/Software
- Michael Birchall (Software)
- John Bunton (Correlator Systems Manager)
- Elaine Sadler (Science Advisor)
- Tim Adams (Consultant)
- Ludi deSouza (Digital Systems Design)
- Martin Leung (Antennas)
- Alan Ng (CSIRO)
- John Tuthill (CSIRO)
- Ron Koenig (CSIRO)
- John Russell (UTas)
- Chris Weimann (UTas)
Observatory Staff
- Duncan Campbell-Wilson (Observatory Manager/Front-end Electronics)
- Adrian Blake (Deputy manager)
- Charles Hemmings (Senior Technical Officer)
- Darshan Thakkar (Digital Engineer)
Associated Collaborators
- Dick Hunstead (Head of Research Group)
- Frank Briggs (ATNF/ANU)
- Daniel Mitchell (Software/RFI)