|System / Subsystem||Funding||Proj. Leader||Proposed||Completed||State|
|1. Australia Telescope Compact Array|
|1.01||Pulsar backend||triennium||M. Oestreich||1996 Apr 2||2002 June 1||terminated|
|1.02||North Spur extension||cip||B.M. Thomas||1996 Nov 1||2000 Jan 1||done|
|1.03||Extra Stations||mnrf1997||J.W. Brooks||1994 Nov 1||2000 Jan 1||done|
|1.04||Common view clock||not_funded||R.N. Manchester||1995 Mar 31||not_started|
|1.05||256MHz backend upgrade||not_funded||W.E. Wilson||1997 Jul 1?||no action|
|1.06||Narrow-band backend||not_funded||W.E. Wilson||1997 Mar 1?||no action|
|2. Parkes 64m Telescope|
|2.01||Pulsar backend||triennium?||M. Oestreich||2000 Oct 26||2002 July 1||terminated|
|2.02||Networking||M.J. Kesteven||1997 Jul 1?||2000 Aug 30||done|
|2.03||Local oscillator and IF upgrade||mnrf1997||G. Graves||1995 Jan 1||done|
|2.04||Common view clock||triennium||R.N. Manchester||1995 Mar 31?||2002 Apr 08||done|
|3. Mopra 22m Telescope|
|3.01||Simultaneous 13/3cm||not_funded||M.J. Kesteven||deleted|
|3.02||15-22m surface extension||unsw contract||M.J. Kesteven||1997 Jan 1||2002 Jan 1||on hold|
|4. Long-Baseline Array|
|4.01||12mm receivers||mnrf1997||M.W. Sinclair||1995 Jan 1||1997 Feb 1||done|
|4.02||Hydrogen maser clocks||W.E. Wilson||1996 May 17||done|
|4.03||S2 playback unit for 7th station||W.E. Wilson||1995 Jan 1||done|
|5. RFI Mitigation|
|5.01||Interference Mitigation Machine (IMM)||mnrf1997?||M.J. Kesteven||2000 Jan 1?||2001 Feb 19||merged|
|6. Computing Systems|
|6.01||ATOMS manpower||triennium||M. Wieringa||1997 Nov 1?||2001 Feb 17||stopped|
|7. Strategic Research|
|7.01||InP MMICs (ESP)||esp||W.E. Wilson||1997 Dec 26||2003 Feb 26||done|
|7.02||Array Technologies||mnrf1997||B.M. Thomas||1995 Jan 1||2000 Jul 1||done|
|7.03||Next generation MMICs||not_funded||M.W. Sinclair
|2000 Jan 1||2001 Oct 15||not_started|
|8. External Contracts|
|8.01||Pulsar backend||not_funded||...||2000 Jan 1?||2003 Feb 14||not_started|
|8.02||UAO (18-cm receiver)||contract||M. McColl||2000 May 1||2002 July 1||completed|
|8.03||Feed design and correlator for Jodrell Bank||contract||...||done|
|8.04||SEST correlator||W.E. Wilson||2000 Apr 30||done|
|8.05||Correlators for the University of Tasmania||...||done|
|8.06||Data Acquisition System (DAS)||contract||...||done|
|8.07||Machining Centre||triennium||J.W. Brooks||2001 Feb 1||completed|
This document is a compliation of completed development projects that at one time or another appeared in the future developments summary document. This should give a rough history of ATNF developments and may be of use in planning new developments.
Projects are moved here after they have been reported to ATUC as being completed. Where there is just a small amount of work to do on a project that is otherwise completed, the project description will be left in the summary document, marked as "done", until the last loose ends are tied up. This means that the start and end dates will be only approximate. Also, this compliation was started in 2001 February; many details of projects completed before that time have been lost.
Although the ATCA now has a pulsar binning mode suitable for imaging it has no general purpose pulse analysis backend. The Pulsar Correlator (PX) will provide many standard pulsar observing techniques not now available on the AT Compact Array. It is a multi-channel receiver backend based on the NASA-SERC correlator chip and utilises the correlator hardware design recently implemented by the ATNF Electronics Group for the Parkes multibeam project. To this design, one new board type (four of them) is added: a versatile accumulating memory with an external pulsar clock common for all channels.
The basic unit handles bandwidths to 64MHz and is expandable in units of 64MHz. Standard operation modes for precision timing, single pulse capture, dynamic spectra (scintillation work), full Stokes polarimetry and searching are provided but the system is versatile enough to be useful in other modes, such as coherent de-dispersion. Because of its standard interfaces, small size and remote observing capability, the device is very attractive as a portable "world" instrument.
This project was terminated at the Future Development Meeting of 13 June 2002.
More information: ATCA Pulsar Backend
The imaging capabilities of the Compact Array at mm-wavelengths will be greatly enhanced by the addition of a North spur to the existing 3km E-W rail track, allowing instantaneous two-dimensional uv-coverage. This is important at the higher frequencies where data quality is strongly dependent on weather conditions and elevation. (The capabilities would be further enhanced with the ability to move the 6km antenna to the existing 3km track section.)
There are five stations situated at 2, 5, 7, 11, and 14 increments (15.3m), the fifth station being 214m from the centre line of the E-W track. The intersection of the North spur line and the existing E-W Compact Array is 106 increments west of station 1. The upgrade task includes the modification of antennas so that they can turn at station 106 and travel north. Observatory staff modified antenna No. 1 in time for the turntables and the new track to be commissioned.
The work under contract to Barclay Mowlem Constructions Ltd has been completed. The new trenches for cabling to service the North Spur stations has also been completed. The ATNF has partly completed the laying of cabling including optic-fibre, some termination work remains. The new stations will not be available until design of the new LO system is complete, and installed.
More information: New ATCA stations and the North Spur. Pictures of the construction are available here.
Compact Array image quality is strongly dependent on the number and distribution of interferometer spacings. Our most compact (375m) imaging configuration comprises only even multiples of the basic 15m increment. This gives grating lobes within the primary beam which makes observations of extended objects, such as Galactic or Magellanic Cloud sources, extremely difficult, even with mosaicing. This problem will become more acute as the Compact Array moves to higher frequencies where many observations will be made only with these very compact configurations, and sources of interest will commonly be larger than the primary beam (45" at 3mm). Four new stations would permit a complementary pair of 375m arrays for a complete 2 day synthesis (presently impossible) and an ultra-compact single-day configuration using a 180m array (presently impossible - the existing 122m array is a highly redundant non-imaging array).
The new east-west stations are located 104, 106, 124, and 125 units east of station number 1 (1 unit = 15.306 m). New stations 124 and 125 lie just to the east of station 22, quite close to the north-west of the control building. Stations 104 and 106 lie between stations 16 and 17 near the Visitors Centre; station 106 is the junction point for the north spur.
The work under contract to Barclay Mowlem Constructions Ltd has been completed. The new trenches for cabling to service the North Spur stations has also been completed. The ATNF has partly completed the laying of cabling including optic-fibre. The new stations will not be available until design of the new LO system is complete, and installed.
Pictures of the construction are available here.
More information: New ATCA stations and the North Spur
This project is to construct a duplicate of the Parkes telescope common-view clock. It may even proceed in parallel with that.
The project was not moving at all, so it was moved to the "done" bin.
The ATCA correlator was designed to operate with a maximum bandwidth of 256MHz. At this bandwidth, 1-bit quantisation is used and 128 independent channels per baseline (to be divided by the number of polarisations and observing frequencies) are available. The present maximum bandwidth is 128MHz and, while the 256MHz upgrade offers no sensitivity gain owing to coarser quantising, it provides important advantages when observing at millimetre wavelengths. Most of the required correlator hardware is already in place but several new antenna-based modules are required to make the wide bandwidth upgrade operational.
At 3mm the 256MHz option yields an instantaneous velocity coverage of 768km/s with a maximum resolution of 6km/s. This is ideal for studying, e.g., CO at redshifts of 0.1 or so, at sky frequencies around 90-100GHz. The performance is similar to that of the VLA correlator observing HI at 1.4GHz, making it familiar to extragalactic astronomers. While studies of red-shifted molecules are topical in astronomy, the wide band ATCA upgrade (which is actually still quite narrow by present-day mm-array standards) will allow the ATCA to better exploit advantages flowing from its southern location and high sensitivity. In particular, it will permit the instrument to undertake a range of extra-galactic spectral line studies which are presently the preserve of the most sensitive northern arrays and which are major science drivers for the very large mm-arrays forecast to be completed in a decade or so.
Status: no action
This has been merged into the Next-generation spectral line correlator project.
Some observations, such as studies of OH maser emission in star-forming regions, stretch the current capacity of the ATCA correlator. The requirement for OH maser work is for all four Stokes parameters (to obtain circular polarisation intensities), with frequency resolution after Hanning smoothing of 1 kHz (0.5kHz before smoothing). This is not currently attainable on the ATCA.
One solution is to place band-limiting filters of width 2 and 1MHz in the control building giving as many as 4096 spectral channels across 1MHz. This development also requires a finer tuning capability in the LO system than the current 1MHz steps.
A second related development is to provide narrow-band filters on the second frequency, allowing simultaneous observations of two widely-spaced spectral lines. This is primarily an issue for the 12mm upgrade if simultaneous observations of the several Ammonia transitions near 23GHz are required.
Status: no action
This project has become part of the Next-generation spectral line correlator project.
Note that some of these requirements are available using the LBA, albeit with considerably greater effort in observing and data reduction.
Most of the requirements for this system will almost certainly be covered by narrowband modes intrinsic to the "Next Generation" spectral line correlator.
The Pulsar Correlator (PX) is a multi-channel receiver backend based on the NASA-SERC correlator chip and utilises the correlator hardware design recently implemented by the ATNF Electronics Group for the Parkes multibeam project. To this design, one new board type (four of them) is added: a versatile accumulating memory with an external pulsar clock common for all channels. The Parkes version of the PX will become an integral part of the Multi-Beam Correlator, with the PX integrator pcb switched in bypass for normal (non pulsar) operation.
This project was terminated at the Future Development Meeting of 13 June 2002.
The Parkes Visitors Centre upgrade has been completed in August 2000 incl. an improved & enlarged building, and an update of the existing slide show.
The Parkes Telescope does not have a standard AT local oscillator and intermediate frequency (IF) distribution system. It therefore lacks frequency agility and bandwidth compared with other AT antennas. This incompatibility also limits flexibility on some programmes such as long baseline interferometry. An upgrade to this system has become necessary to match the improvements offered by the prime focus upgrade.
More information: Parkes RF/IF conversion system
This project is to build and operate a common-view GPS clock monitoring system for Parkes observatory in collaboration with the Time Standards group at CTIP. This system should give the time difference between UTC(PKS) and UTC to a precision of a few nanoseconds or better.
The clock is completed and operating
For VLBI astrometry and geodesy it is highly desirable to observe simultaneously at 13 and 3cm wavelength (2.3 and 8.4GHz). Mopra is a fixed antenna and hence more appropriate for such applications than one of the Compact Array antennas. Mopra would be a valuable site for such programmes, as access to Tidbinbilla is likely to become increasingly difficult.
The Mopra dish surface was effectively transparent to mm-waves beyond the 15m diameter of solid panels. Extension of the solid surface to 22m, which is now complete, will render an approximately two-fold increase in sensitivity, greatly extending the range of useful observations possible in these bands. The panels have a surface accuracy of 100 microns. New holography equipment has been built by Astrowave Ptl; it has been trialled at Mopra. We hope to achieve an initial panel setting of better than 200 microns (RMS) (This corresponds to a Ruze efficiency of 60% at 86 GHz; to this must be added the other loss factors, such as blockage, illumination). Tests are underway to characterise the performance at Mopra at 86 GHz.
The proposal is to retain the shaped surface, as this is the simpler engineering solution and gives a higher on-axis performance. The penalty is a reduced off-axis performance, so that operation with focal-plane arrays, or position-switching between off-axis feeds, will require either reshaping the reflector or the use of phase-correcting optics.
Status: on hold
The ATNF and the School of Physics of the University of New South Wales (UNSW) have agreed to participate in a joint venture to develop the Mopra antenna for the benefit of all Australian astronomers, and to provide greater access to the upgraded facility by UNSW astronomers. This Memorandum of Understanding (MOU) will take effect for the three periods (nominally 1 July - 30 September) of about three months each of 1999, 2000, and 2001.
UNSW will contribute to the operational expenses and towards the cost of resurfacing the antenna and provide an expert observer (Dr. Ramesh Balasubrahmanyam) on duty at Mopra. The ATNF will provide access to the antenna, in each of the specified periods, to UNSW for exclusive use for a period of 6 weeks, followed by 6 weeks during which the antenna will be assigned to users via the normal ATNF time assignment process, but supported by the UNSW expert observer.
On hold till the holography system is operational.
The provision of a 12mm receiver for Mopra would provide a southern-hemisphere imaging VLBI array comparable to northern networks, but with two considerable advantages: access to the Galaxy, and access to the considerable time available for observing Southern sources with VSOP. Imaging and astrometric observations of Galactic HO maser sources address well-established scientific goals, while the recent discovery of a high-velocity HO molecular ring around the nucleus of NGC4258 has opened up exciting new possibilities at this frequency.
The "VSOP" 12mm receiver has been completed. This receiver will eventually be replaced with a 12mm receiver identical to those built for the ATCA.
More information: VLBI Upgrade
All LBA telescopes are currently equipped with Hydrogen masers. However, two LBA telescopes (Hobart and Parkes) currently operate with borrowed H-masers. The future of these masers is uncertain beyond 1-2 years and their loss would severely curtail existing and future VLBI programmes. The successful stellar astrometry/frame-tie programme conducted between Hobart, Parkes and Tidbinbilla for example, would abruptly cease with the loss of even one of these masers. The pulsar timing programme at Parkes would also be heavily affected by the loss of the maser. Provision for the future purchase of two additional masers for these telescopes would therefore be a prudent step, to safeguard existing capabilities.
Acquisition of H-masers for Mopra, Hobart and Ceduna was supported by MNRF funding. The University of Tasmania has loaned the ATNF its Hobart maser and it is currently installed at Narrabri.
More information: VLBI Upgrade
Sufficient AT correlator chips exist to double the existing correlating capacity (number of baselines) of the LBA correlator, for relatively modest cost, requiring only the additional S2 playbacks to be added to form a full 8 station correlator. Should additional S2 recorders be installed at Mauna Kea, Shanghai and other APT telescopes, this extra capacity would reduce correlating overheads substantially.
This project is to develop interference mitigation, exploiting the "post-correlation" technique and specialised hardware. An L-band feedhorn has been adapted to provide the reference antenna used in this scheme, and low-noise room temperature amplifiers have been purchased.
Recent experiments at Narrabri have included a successful 12-hour run at 1503 MHz, countering the pay-TV on Mt. Dowe. A test at 1610 MHz (countering the Glonass constellation) is at the data analysis stage, and looks promising. The trials so far have been narrow band (4 and 8 MHz); wide-band trials at S-band are under consideration.
In Feb 2001 this project was merged with the strategic research programme, "Interference Excision".
In an effort to rationalise the telescope and data management systems at the various ATNF sites the AT Observatory Management System (ATOMS) is being developed. In the long term, this system envisages all sites having the same hardware and software systems for telescope control and data acquisition. In the short term, work is proceeding in the following areas:
Project dormant - all effort is being directed at ACC development. No MNRF money is being spent on this item; both salaries involved are now paid from the Narrabri computing budget.
More information: Australia Telescope Observatory Management System (ATOMS)
A collaboration to develop InP monolithic millimetre integrated circuit
(MMIC) devices for the mm-wave upgrade to the ATNF is underway with the
Division of TIP.
Money has been obtained from the Special Executive Fund to develop a suite of InP MMICs to match the three high-frequency upgrade bands on the ATCA (3, 7, and 12mm) which will give us the best possible sensitivity. These will be our LNA for the 3mm/12mm receivers. High speed InP digitisers are also being developed under the auspices of this programme.
MMICs developed under this project are now installed in 3mm and 12mm systems on three antennas of the ATCA. Their performance has been very good. All the MMICs for 12mm LNAs from the first fabrication run (wafer CSIR8) have now been used. Upgraded designs have been produced in a second InP fabrication run (CSR15). Four existing LNAs using chips from the CSIR8 wafer will be upgraded with chips from CSR15. We have over 100 packaged chips from CSR15 in hand. This project is now completed, with respect to the 12mm receivers.
3.5mm LNAs from wafers CSIR8 and CSR15 will be used in the production 3.5mm receiver systems. These chips can cover 85 to 105 GHz. A design to cover 85-115 GHz now exists, but has not been fully tested.
This project was done in conjunction with RMIT and explored focal plane array technologies. The project was coupled with the MNRF Interference Excision development.
This development was supported by MNRF funding which has now finished. Further work may take place within the SKA project.
More information: Radio-frequency interference mitigation
The MMIC developments undertaken as part of the Executive's Special Project have placed ATNF and CTIP in a good position to lead the astronomical world in this technology. These devices have good potential for wide application in high-frequency radio astronomy:
Producing the MMIC device designs is one thing, but solving all the problems of bonding, packaging and cooling has required much development work and device redesigns. We now have these rugged designs and sound grasp of all the technicalities in the deployment chain, from the design table to cold sky. ATNF should continue this development to maintain our leading position.
This project is now part of MNRF2, and was removed as it was no longer a separate item.
Interest has been expressed by NRAO in the purchase from the AT of a pulsar correlator of the type currently under construction for the ATCA.
Interest from NRAO has long since evaporated. This project was renamed, to the Parkes project "Pulsar Extension of Multibeam Correlator".
This project is to design and construct an 18cm cryogenic receiver for the Urumqui Astronomical Observatory.
Construction was completed, and testing began, in early May 2002. THe receiver was found to perform within the predicted design specifications.
The receiver and helium compressor were packaged on 20 May and sent to China the following week. The expected installation date at UAO was 24th June.
The ATNF has been contracted by NRAL (Nuffield Radio Astronomy Laboratory) to design a four-horn feed and eight-channel spectral-line correlator for the Jodrell Bank Mark-I telescope. The correlator will be based on the Parkes multibeam design. This development is in exchange for the contribution from Jodrell Bank towards the multibeam LNA development and construction.
ATNF is building a wideband spectral-line correlator for the 15m Swedish-ESO Submillimetre Telescope (SEST) in return for 10% of the Swedish observing time on the SEST (about 18 days). The ATNF provides the hardware and staff for this correlator. It will provide two 2GHz bands, each with 2048 channels and 3-level sampling. Bandwidths of 1GHz, 512MHz, 256MHz, 128MHz and 64MHz will also be possible.
The correlator was delivered to SEST in April 2000.
The University of Tasmania has contracted the ATNF to build two correlators of the same design as that built by the ATNF for the multibeam receiver at Parkes. The correlators are for spectral-line observations at Hobart and Ceduna, and will each be dual-channel, 64MHz bandwidth with 1024 spectral channels.
The University of Tasmania has contracted the ATNF to build two digital filter and sampler systems, for use with the S2 VLBI recorder and for single-dish spectral-line observations. One unit will be deployed at Hobart, the other at Ceduna. Identical units are also in production for the ATNF telescopes at Narrabri (two units), Parkes and Mopra. Additional units are also to be supplied for Tidbinbilla, Perth and Hartebeesthoek.
Interest has also been expressed from Taiwan and Russia in the purchase of these units.
In our development projects, many custom-built parts are required and usually they are specified with very fine tolerances. To machine these parts requires adequate machining plant and a considerable degree of skill. This item is to mark the need for purchase of computer-controlled milling machines which will boost productivity and enable us to tender for more projects.
The new machining centre was installed in the workshop in June 2002, at a cost of $234k. Early reports on quality and productivity levels achieved with the new capability are very positive.