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ASKAP Technical Update
CSIRO Astronomy and Space Science March 2010

The ASKAP Technical Update contains a brief summary of recent science and technical developments related to the Australian SKA Pathfinder (ASKAP) project. It documents, at a top level, recent developments and milestones reached by core CSIRO ASKAP project teams. Each issue also looks at an aspect of key ASKAP activity. Previous issues can be read online at www.atnf.csiro.au/projects/askap. Radio Receivers Set to Shrink
CSIRO and Australian company Sapphicon Semiconductor Pty Ltd have signed an agreement to jointly develop a complete radio receiver on a chip measuring just 5 mm x 5 mm that could eventually be used in mobile phones and other communications technologies. The development of a low-cost, ultrahigh-bandwidth `system-on-chip' device could also replace traditional receiver s currently used in radio astronomy applications many of which are about the size of a small refrigerator. Able to sample about 600 MHz around a central frequency of around 1400 MHz, the chip's fir st test will be in the telescope's innovative phased array feed (PAF) that sits at the focal centre of each ASKAP dish to receive incoming cosmic radio waves. It is also a potential technology for the SKA. The chip will minimise the size and weight of the PAF, reduce cost and power, and facilitate maintenance. It will be developed using Sapphicon Semiconductor's Silicon-onSapphire CMOS process. "A sapphire substrate is not `lossy'," said Andrew Brawley, CEO of Sapphicon Semiconductor. "That's impor tant for an application such as radio astronomy because it minimises losses in integrated passive components, significantly improving their performance . Perhaps the biggest advantage is that so much circuitr y ­ RF, logic, mixed-signal and passives ­ can be incorporated into the same chip. This is real miniaturisation and could open up whole new product mar kets," Mr Brawley said. > CSIRO's Suzy Jackson inspecting receiver chips. Photo credit: Chris Walsh, Patrick Jones Photographic Studio. International researcher s developing the Square Kilometre Array radio telescope are interested in the R&D proposed by CSIRO and Sapphicon. No other group is developing a fully integrated single-chip receiver. The project will take about two year s to complete and will involve a number of stages of sub-component development and testing. Following its collaboration with Sapphicon and CSIRO on ear lier proof-of-concept projects, the Centre for Technology Infusion at La Trobe Univer sity in Melbourne will wor k with Sapphicon and CSIRO in the development of the novel chip. CSIRO and Sapphicon welcome discussion with other industr y par tner s interested in this area of R&D. For more information contact Dr Carole Jackson (ph 02 9372 4407 or email carole.jackson@csiro.au).

ASKAP Receives First Signal
Constr uction of ASKAP's fir st antenna has progressed rapidly and the antenna has recently received its fir st radio signals. The fir st of 36 identical 12-metre dishes that will make up the ASKAP telescope, the antenna was assembled over the Australian summer at the Murchison Radio-astronomy Obser vator y in the Mid West region of Western Australia. The fir st radio signals were received from a satellite and were par t of a project to measure the shape of the antenna's surface using holography. "It's a great moment ­ the fir st time a telescope receives light or radio waves is always ver y satisfying and exciting. It means the project is firmly on track," said Dr Dave DeBoer, CSIRO ASKAP Project Director. "The test results show that the antenna is wor king beautifully, beyond specifications."

> The first ASKAP antenna, now erected in Western Australia. Photo credit: Dave DeBoer, CSIRO.


IPT Progress Update
ASKAP's Integrated Project Teams have been reaching key milestones and progressing towards successful deliver y of the project.

ASKAP Computing
Additional features, including a new scan-with-offset mode, have been added to the software for monitoring and controlling the Par kes Testbed Facility's 12-metre antenna. Integration of the EPICS digital receiver driver to the digital receiver hardware has commenced, and the driver is successfully reading monitoring points from the digital receiver's control board. Realistic sky model simulations have been passed through the ASKAP imaging software to produce simulated output images for the science teams to test their source-finding algorithms.

includes electronics and receiver systems for a complete ASKAP antenna integrated with a full-scale wooden model of an antenna pedestal, has progressed.

ASKAP Science and User Policy
The ten major science projects to use ASKAP in its fir st five year s have star ted their Design Studies phase. This has focused on testing the projects' sourcefinding algorithms on simulated images created by the ASKAP Computing team, and (for those teams that will supply external hardware to enhance ASKAP's capabilities) assessing their power and space needs at the central ASKAP site.

ASKAP Antennas
The fir st ASKAP antenna has been assembled at the Murchison Radioastronomy Obser vator y (MRO) by the CETC54 engineering team and site acceptance testing concluded on 22 Januar y. The ASKAP team has commenced the fit-out and integration of the antenna, and also star ted commissioning activities. Holography has been used to ver y accurately measure the dish surface performance. The manufacture of Antennas 2 ­ 6 is on schedule and they are expected to be delivered to the MRO in the third quar ter of the year.

ASKAP Data and Signal Transport
Design of the unit for controlling the antennas' local oscillator, timing signals and internal communications continued to be refined and scripts have been developed for ethernet communications to the unit via the built-in digital systems control card. The entr y and termination requirements for the underground 216-count fibre from the antennas to ASKAP's central building have largely been resolved and a trial section is being evaluated. In Febr uar y AARNet, the telecommunications carrier for 380km of fibre cable between the MRO and Geraldton, published a tender request for installation of the cable.

SKA Related Activities
Wor k continued with Aurecon, the SKA Program Development Office and South African representatives on radio frequency interference standards for possible SKA array station configurations. ASKAP team member s attended the SKA system concept design review, and par ticipated in SKA science and industr y meetings in New Zealand.
For further information: G a b by R u s s e l l Communication O f ficer C S I R O A s t r o n o my a n d S p a c e S c i e n c e Phone: +61 2 9372 4339 Email: gabby. r ussell @ csir o. au Web: w w w. atnf.csir o. au /pr ojec t s /a sk ap

ASKAP Analog Systems
The mechanical design of the ASKAP prime focus receiver package is almost complete. Many par ts have been fabricated and the fir st `dr y fit-up' is progressing well. Prototyping of the receiver electronics is also progressing well with the fir st prototypes of all the main circuit boards, which typically ser ve four to eight receiver channels, now assembled and tested. After some minor revisions, sufficient quantities of the receiver electronics for the fir st two receiver systems will be manufactured.

ASKAP MRO Related Activities
Wor k continued with consultants Aurecon on the design of MRO suppor t infrastr ucture including roads, power distribution, the control building and its cooling system. Accommodation facilities at Boolardy Homestead have been completed and temporar y diesel generator s have been installed.

ASKAP Digital Systems
The initial design for ASKAP's digital system has been put into production for the fir st antenna and is nearing completion. Fur ther wor k is being done on the design of a spring tensioned floating heatsink to attach to the high power field programmable gate array devices on the signal processing boards. System integration has star ted with completed boards being placed into the prototype cabinets and optical fibre connecting the systems, and initial connectivity looks good. Firmware for the digital receiver is almost complete.

ASKAP System Engineering, Integration and Commissioning
Testing of ASKAP's prototype phased array feed took place at the Par kes Testbed Facility in ear ly December 2009 and will be repeated in March 2010. Development of the ASKAP testbed system at CSIRO's Mar sfield site, which