ATNF Telescope Status for 2023OCT

All ATNF Telescope Applications for 2023OCT must be submitted using OPAL.

The deadline for all proposals is 07:00 UT (17:00 Sydney local time) on Thursday, 15 June 2023.

Summary of major changes for 2023OCT

  • Proposals are now accepted for ASKAP Guest Science time (up to 150 hours per semester). Details here.
  • We expect that the Cryogenically Cooled Phased Array Feed (CryoPAF) will be installed on the Parkes 64-m telescope, Murriyang, in August 2023. We are seeking expressions of interest for shared-risk proposals to take place during January through March 2024. Details here.
  • We anticipate introducing a new Longterm Project scheme in the 2024APR semester. Details were provided in this ATUC presentation. We encourage teams to submit proposals in 2023OCT that could transition to Longterm Projects in future.
  • ATNF proposals are fully anonymised. The ATNF TAC has discretion to reduce scores for proposals that reveal applicant identities. Further details here.
  • An optional LaTeX template for ATNF scientific justifications, with appropriate BibTeX setup to support anonymisation, is available here.

For 2023OCT, we are continuing to use a new version of the OPAL system. Users are encouraged to report any issues via email (atnf-datasup@csiro.au). The file format for cover sheets and observations tables has changed from 2022OCT onward. Files from 2022APR and previous semesters (in OXML format) should be re-loaded into the OPAL editors, carefully re-checked and updated, and saved in the new format (JSON). 

Telescope availability

For 2023OCT, ATNF proposals will be accepted for the:

  • Australian SKA Pathfinder (ASKAP);
  • Australia Telescope Compact Array (ATCA);
  • Murriyang, the Parkes 64m telescope;
  • Tidbinbilla 70-m (DSS-43) and 34-m (DSS-34) antennas; and
  • Long Baseline Array.

Proposal guidance

  • ATNF has moved to full anonymisation during the TAC review process. Proposers must not list their team members in the justification. Past projects should be referred to by proposal code rather than by the name of the PI. We also encourage proposers to consider using numbered references particularly when self-citations are included. An optional LaTeX template that uses this approach can be obtained here.
  • Note that Large Proposals (>400 hours over the lifetime of the project) are required to include in their justifications a section describing team roles/contributions (see Section 3.4 of the OPAL Users Guide). In order to do this, and also avoid listing team members in the justification, proposers can state the various skills required to conduct the project, and refer to the size and composition of the proposing team. For example, "Our team comprises n members, and possesses x people with expertise in planning and conducting these observations, y people with experience in reducing the data, and z members able to interpret the data within the theoretical modelling described earlier."

Impact of instrument upgrades for 2023OCT

  • Several instrument upgrades are underway, and the associated project timescales will impose the need for flexibility in ATNF scheduling during 2023OCT. Specific details for individual telescopes are provided below.
  • ATCA: This may be the last semester in which CABB will be available. If your science needs CABB, please emphasise this in your justification. Also please note the current state of CABB (which is summarised in the section below, and can be monitored on the ATCA webpages and via communications from Jamie Stevens) and contingencies that may be required to successfully deliver spectral line observations, e.g. duplication of zoom bands. It may be better to wait for BIGCAT for spectral-line projects, unless your science requires time this semester.
  • ATCA: BIGCAT testing will continue in 2023OCT, and may affect the functionality of the telescope. Effort to develop and test BIGCAT is split with other projects, and so we can not accurately anticipate when the testing will be scheduled. We may have to reschedule observations after the schedule is published, and we may choose to release the schedule in parts. Given the current timeline of BIGCAT installation, we anticipate having at least 3-4 months of observing time available in 2023OCT prior to BIGCAT commissioning.
  • ATCA: NAPA proposals for rapid response observations (within ~10 minutes of an alert) are welcomed. A rapid response mode for the ATCA is now in operation. Proposers seeking to use this mode must contact Jamie Stevens (Jamie.Stevens [at] csiro.au) and demonstrate a working triggering mechanism before being allowed to send triggers to the telescope.
  • Parkes: Scheduling for the semester is likely to be impacted by activities in preparation for the CryoPAF. There is a high likelihood for a month-long shutdown late in the 2023OCT semester as part of the "20-year Maintenance" operations during which there will be no observing.

General Information

Observing support, training, and remote observing qualification requirements have recently been updated and are described in the ATNF observing support model.

Observations with ASKAP are automated, and all other ATNF telescopes are remotely user-operated. Observations from the Marsfield or Perth Science Operations Centres are supported but not required.

Telescope time that is unallocated when the 6-month observing schedules for the semester are released can be requested as Director's time (sometimes referred to as "green time", as that's how it appears in the graphical version of the schedules).

Target of Opportunity proposals can be submitted at any time. This is intended for observations which are time critical. Proposals that are not time critical should be submitted through the regular TAC process when possible, rather than relying on applications for Director's time or Target of Opportunity time.

Large Projects are projects that require a total of more than 400 hours of observing time over the lifetime of the project. Please read the Large Projects web page in addition to the information on this page. Large Proposals are required to include in their justifications a section describing team roles/contributions (see Section 3.4 of the OPAL Users Guide for more details).

A document outlining Time Assignment Committee procedures is available from the TAC web page.

For further information contact George Heald (George.Heald [at] csiro.au).

ASKAP

ASKAP is designed for autonomous operations in pre-defined modes with high efficiency. Guest Science Project (GSP) observations, like Survey Science Project (SSP) observations, will be fully specified in advance, then scheduled autonomously and dynamically by the automated scheduler SAURON based on the identified constraints. The data will be calibrated, processed, and archived according to a pre-defined processing template, chosen from an existing and well-tested set (unless there is a strong case for adjusting any of the parameters). Proposers will be notified when their data products are available in the science data archive, CASDA. Recipients of data will be required to submit a short validation report after being granted access and before the data can be released and used for science.

For this first round of GSPs we are broadly offering two well-established modes: continuum observations with 10” resolution at a sky frequency of 944 MHz, bandwidth of 288 MHz. and a typical integration time of 10 hours (EMU-mode), or spectral line observations with 18.5 kHz spectral channels and 30” resolution at a sky frequency of 1368 MHz with 144 MHz of bandwidth and a typical integration time of 8 hours (WALLABY-mode). These modes by default generate Stokes I data products. In addition to the two most fundamental modes above, we offer some variations as follows: 

  • POSSUM mode extends the EMU or WALLABY mode by adding full Stokes parameters, additionally with a “continuum cube” containing 1 MHz frequency resolution for spectral index or rotation measure studies. 
  • VAST mode differs from EMU continuum mode by providing Stokes I & V data and is optimised for snapshot observations of 12 minutes, for covering wide areas or searching for transients with multiple epoch-based observations of the same field(s). It uses a slightly different sky frequency of 888 MHz. 
  • FLASH mode is a form of spectral line observing designed for absorption-line science, with some adjustments to the beamforming to ensure broad lines are well characterised, and a sky frequency of 856 MHz optimised for high-redshift HI. 

For any custom variations to the above, we welcome inquiries from the community that we can investigate for support in future semesters (please get in touch with members of the ASKAP Operations team for questions in this context). 

ASKAP’s continuum sensitivity yields an RMS noise level of about 200 μJy/beam at 900 MHz in 15 minutes of observing time. With longer 10-hour observations the RMS noise level drops to about 20 μJy/beam. Detailed system information can be found in the following locations: 

  1. Australian square kilometre array pathfinder 1: system description. Hotan et. al. https://ui.adsabs.harvard.edu/abs/2021PASA...38....9H/abstract 
  2. The ASKAP Guest Science user guide: https://confluence.csiro.au/display/askapsst/ASKAP+Guest+Science
  3. The ASKAP observation guide: https://confluence.csiro.au/display/askapsst/ASKAP+Observation+Guide 

Target of Opportunity time for ASKAP can be requested via this form.

Australia Telescope Compact Array (ATCA)

ATCA Observing

Remote observing with the ATCA is the default mode of observing, but it is also possible to observe from the Marsfield Science Operations Centre (SOC) or the Perth SOC. Observing at the Narrabri site is encouraged for observers who wish to visit the observatory, and for complex or non-standard observations, or in other circumstances where this is the more sensible option. The Narrabri observatory is considered a remote observing site with regard to support levels for normal observations. New observers are able to be trained remotely, but are encouraged to travel to the SOC if they prefer.

BIGCAT Upgrade Testing

The current plan is to install the new BIGCAT digital system late in the 2023OCT semester (a delay from our plan last semester). If your science requires CABB data specifically, please emphasise this in your justification.

Array configurations

For 2023OCT, due to the state of the power transmission equipment on site, we may choose particular array configurations based on which station posts are able to be powered. At the least, a 6km configuration, a 1.5km configuration, a 750m configuration and a hybrid configuration will be offered during the semester. The 2023APR semester will end in H168 array and so this may be continued for the first weeks of 2023OCT. Configurations will only be scheduled if there is sufficient proposal demand for them.

CABB modes

The Compact Array Broadband Backend (CABB) modes that will be available for 2023APR semester are:

  1. CFB 1M: A bandwidth of 2 GHz with 2048 x 1-MHz channels in each IF band, but no "zoom" bands.
  2. CFB 1M-0.5k: A bandwidth of 2 GHz with 2048 x 1-MHz channels and (optionally) a fine resolution of 0.5 kHz in up to 16 "zoom" bands (each with 2048 channels across 1 MHz) in each IF band.
  3. CFB 64M-32k: A bandwidth of 2 GHz with 32 x 64-MHz channels and (optionally) a fine resolution of 32 kHz in up to 16 zoom bands (each with 2048 channels across 64 MHz) in each IF band.
  4. CFB 1M/64M: A "hybrid" mode with 2048 x 1-MHz (but no zooms) in one IF band, and 32 x 64-MHz channels with (optionally) up to 16 zoom bands with 2048 channels across each 64 MHz in the other IF band.
  5. VLBI backend tied-array mode: This allows you to capture up to 2 x 64 MHz dual polarisation bands with both CABB correlations and 2 bit sampled raw voltage output, using the VLBI backend and recorders. Up to 2x16 MHz dual polarisation bands with 8 bit sampled voltages is also available. If you choose to use ATCA in this mode, without requesting any other LBA station or correlation by S&A, you only need to write an ATCA proposal. This mode has some restrictions however, and proposers who are interested in using this mode must contact the LBA System Scientist Phil Edwards (Philip.Edwards [at] csiro.au) to discuss what is possible. You must include in your proposal a short description of how you will process the data and data transport logistics.

Both CABB IFs are degraded while using zoom modes, and will likely remain degraded for the rest of CABB's life. At the moment, 2 of the 16 blocks in each IF do not form usable zooms in both 1 MHz and 64 MHz zoom modes. Please note though that these problems do not affect the continuum products. The pulsar and high-time-resolution modes too are degraded due to these bad blocks, and so we no longer offer them.

Unless your spectral-line and/or high-time-resolution science is time-sensitive, or uses few zooms in each IF, it may be wiser to wait for BIGCAT than risk poor data with CABB. As it is difficult to predict which block will be responsible for each zoom before your observations start, we recommend that observers seek observatory assistance with determining exact configurations. Please contact Jamie Stevens for further information if you are concerned this may impact your science.

More information on CABB is available from the CABB web page.

Compact Array receivers and frequency ranges

The 16-cm band receivers provide an instantaneous frequency coverage from 1.1 to 3.1 GHz (although the usable bandwidth is reduced by typically 30% by Radio Frequency Interference [RFI] -- the impact of RFI on the 16cm band can be seen at this webpage.). The 16-cm band receivers have an improved sensitivity over the original 20- and 13-cm receivers, and include new ortho-mode-transducers, significantly improving the polarisation performance toward the top end of the band.

The 4-cm band receivers cover the band from 4 GHz to 12 GHz. These receivers provide significantly improved system temperatures over the original 6- and 3-cm receivers. The focus positions for the antennas in the 4cm band differ from those of other bands, which should be borne in mind if changing between bands during an observation. It takes about 2 minutes to refocus the antennas.

In the 15-mm (16--25 GHz), 7-mm (30--50 GHz) and 3-mm (83.5--106 GHz) bands, two 2GHz-wide intermediate frequency bands may be selected within an 8 GHz bandwidth. In the 7-mm band, both band centres must be either greater than 41 GHz (the point at which the conversion changes from lower side-band to upper side-band) or both less than 41 GHz. Observing is possible with the standard 15-mm and 7-mm systems on all six antennas, and 3-mm systems on five antennas: there is no 3mm receiver on CA06. Note that the 3mm receivers are ageing and that, as spare parts are limited, or non-existent, component failure in a receiver may not be able to be repaired in a timely manner, or at all.

The ATCA sensitivity calculator provides a means of determining the sensitivity characteristics of observations, and can include the reduction in bandwidth expected due to RFI in the 16cm band.

Millimetre observing

Observing at 3 mm generally starts in May and ends in mid-October. Proposers are reminded that the primary flux density calibrator at 3 mm is Uranus, which in October 2023 will be near a R.A. of 3h20m and declination of +18d01m. Proposals for 3-mm observations that require accurate flux calibration should request time for observations of Uranus (if the array configuration allows). For 7-mm observations with CABB, PKS 1934-638 is sufficiently strong to be used as a primary flux density calibrator, and should be preferred over Uranus for all projects. Proposers requiring their own observations of Uranus (at special frequencies, or at a time when their main target has set, for example), should make this clear in the observations table and justification of their proposal. For secondary calibration at 3- and 7-mm, Observatory staff will calibrate a number of bright AGN, spread over the full range of R.A., against Uranus (at 3mm) and 1934-638 (at 7mm) at the standard continuum observing frequencies throughout the semester.

The array is outfitted with Water Vapour Radiometers (WVRs) provided by the University of New South Wales. Experience to date indicates that these units will, in some conditions, allow corrections to the measured phases on longer baselines to be made, improving phase stability and sensitivity. Interested mm-wavelength observers will be able to use of this capability during 2023OCT. Details of the system are available at the WVR webpage.

Further information

Parkes radio telescope, Murriyang

Receiver availability

The default receiver pairing will be Ultra-Wideband Low frequency receiver (UWL) along with the Cryogenically Cooled Phased Array Feed (CryoPAF); the latter will be installed from August 2023 for scientific commissioning. High-frequency receivers such as 13M and MARS will replace the UWL when required. Previous discussion details with regards to receiver fleet development and rationalisation can be found in the linked document here and ATUC presentation here.

Subject to timely installation of the CryoPAF, we anticipate the initial engineering and science commissioning period to span the months of October through December 2023. Subsequently, we may be able to offer "shared-risk" CryoPAF observing for the remainder of the 2023OCT semester (i.e., January through March 2024), with limited modes and features as described here. Expressions of interest in this proposal round are welcome, with the following conditions:

  • Shared-risk proposals should represent reasonably short requests for time during the 2023OCT semester, perhaps framed as a pilot or feasibility study for an anticipated survey or project requiring a larger time request in future semesters;
  • Some aspects of the beam forming and data processing software are expected to be only partially implemented, so shared-risk observers will be requested to contribute to development and testing, as well as providing feedback to the observatory team;
  • Shared-risk time will be allocated subject to evidence of awareness of, and capacity to manage, the large data rates produced by CryoPAF - particularly for pulsar search mode;
  • Shared-risk observers will be strongly encouraged to visit ATNF at Marsfield and/or Parkes to work with staff on setting instrument configuration, determining the state of the system and initialising observing, with some financial support for travel and accommodation available on request.

The key contact for CryoPAF installation and commissioning plans, as well as information about associated visits and travel support, is Simon Johnston (Simon.Johnston [at] csiro.au), CryoPAF Project Scientist.

Backend Availability

DFB4 is not available. Please request MEDUSA or other backend as below.

MEDUSA is a GPU based backend and details of the available modes can be found in the User's Guide here (with other modes driven by proposals, acknowledging shared risk development). Whilst we await the Ultra-Wideband High frequency receiver, UWH (a 4-32GHz receiver), MEDUSA can be used with the UWL, plus the Mars and 13mm high frequency legacy receivers. For those intending to use MEDUSA please include details of the backend capabilities required.

Other available backends:

  • Breakthrough Listen backend is available for scientific use up to 50hrs per semester, please see this webpage for details and contact Danny Price to enquire as to availability.
  • VLBI backends Multiple VLBI backends (LBADR, MEDUSA) are available for non-LBA VLBI and single dish voltage capture. The LBADR system allows you to capture up to 2 x 64 MHz (1 Gbps) or 8x16 MHz (512 Mbps) dual polarisation bands with 2-bit sampled raw voltage output, or 2x16 MHz dual polarisation bands with 8-bit sampled voltage. The MEDUSA GPU is now capable of a VLBI voltage capture mode. Data recording up to 8 Gbps should be available (2 GHz bandwidth with 2bit sampling). A bit depth of 2,4 or 8 bits/sample is supported. If you choose to use Parkes in this mode, without requesting any other LBA station or VLBI correlation by ATNF, you only need to write a Parkes proposal. These modes have restrictions: proposers who are interested in using this must contact Chris Phillips to discuss what is possible. You must include in your proposal a short description of how you will process the data and data transport logistics.

Data Rates and Volumes

Data from Parkes observations are archived in ATOA (the Australia Telescope On-line Archive) or the CSIRO Data Access Portal (DAP). Given the high data rate of the receivers it is necessary to know the expected data requirements to manage data access, archiving and scheduling. We cannot guarantee availability of all recorded data products if your observations exceed the proposed data rates.

The cover sheet for Parkes proposals specifically requests the following information for all projects:

  • State your expected data rate in TB per hour
  • Are you recording more than 10TB in total for this semester [yes/no]? (if yes, data may not be archived in DAP for pulsar data or ATOA for spectral line/continuum data after 10TB have been taken)
  • Identify your data endpoint [options are ATNF bookable disk space, CSIRO HPC, other]
  • Have you requested adequate storage on your data endpoint [yes/no]? 
  • There is a checkbox confirming the user has read and agree to the following terms: Data rates from Parkes receivers can be as high as 10TB per hour - it takes time to transfer these volumes, so please be mindful that your observations may have adverse effects on the next set of observations. For scheduling and archiving purposes, it is essential that we know the maximum data rates and volumes that your project will produce, and that you have planned adequate storage for your data. If you exceed your stated data rate/volume, then we may need to delete the data before you are able to access them, and they will not be archived.

To assist in determining your data rate an equation is provided below, and the DHAGU? interface will also calculate your data rate when generating a parameter set. An email notification to our data management team will be triggered if the data rate from a parameter set exceeds 1TB per hour.

The following can be used to calculate data rates per beam (single beam for the UWL, maximum 72 beams for the Cryo-PAF):

  • Pulsar Search: File size [bytes] = Nchan x Npol x Nbit/8 x Tobs/Tsamp
  • Pulsar Fold: File size [bytes] = Nchan x Npol x Nbin x 16/8 x Nsub
  • Spectral line mode: File size [bytes] = Nc_sb x Nsb x Npol x Ndump x 32/8
  • Voltage Capture (non-standard): File size per zoom band [bytes] = Nbit/8 x BW x 1e6 x 2 x Tobs x 2

where:

  • Nc_sb = number of channels per subband

  • Nsb = number of subbands (normally 26 for the UWL)
  • Nsub = number of subintegrations in pulsar fold mode
  • Nchan = total number of channels = Nc_sb * Nsb
  • Npol = number of polarisation states (1, 2 or 4)
  • Nbit = number of bits/sample (1, 2, 8, 16 or 32)
  • Tobs = observation time (seconds)
  • Tsamp = sampling time (seconds)
  • Ndump = number of spectral dumps (the total integration divided by the spectral dump time (seconds))
  • BW = bandwidth in MHz

Noting that the total data volume will be a few percent larger than that given by the equation because of the need to store meta-data information.

Contracted telescope usage

Breakthrough Listen will be allocated of the order of 200hrs of Parkes observing time in the 2023OCT semester. The Breakthrough Foundation is not guaranteed any more than 30% of time at any given local sidereal time (LST) range (hour) each month. Commensal use of Breakthrough Listen data is possible (the data is not proprietary) and does not require a proposal to be submitted for consideration by the ATNF Time Assignment Committee. Data is obtained for the P595 project (PULSE at Parkes) and PX600 (a Galactic Centre search) commensally and can be found on the DAP.

In addition to Breakthrough Listen there are also agreements with an NAOC FAST collaboration for 144 hrs per semester; Intuitive Machines (lunar lander tracking) for approximately 140hrs; and SpaceX for approximately 40 hours.

Spacecraft tracking is treated like a NAPA trigger and may override scheduled astronomy observations. Observatory staff will contact affected observers and work with projects to reschedule any lost time as promptly as possible.

Observing Information

Remote observing with the Parkes telescope is the default mode of observing. It is also possible to observe from the Marsfield Science Operations Centre (SOC), the Perth SOC, or Parkes itself (for complex or non-standard observations, or in other circumstances where this is the more sensible option). Although observing onsite at Parkes is not fully supported (e.g., there is no onsite accommodation), we do encourage site visits during working hours for those interested.

Remote assistance can be sought during working hours through the PORTAL. Local Parkes staff will continue to provide the first point of contact for matters relating to safety of the telescope, and equipment.

Further information

Proposers intending to start a new project are advised to contact Stacy Mader (Stacy.Mader [at] csiro.au), to discuss their requirements and availability of configurations before proposal submission. For further information on all Parkes capabilities please refer to the Parkes Radio Telescope Users Guide.

Tidbinbilla

In the 2023OCT semester the 70-m and 34-m antennas at Tidbinbilla will have some availability for single-dish use. Access to Tidbinbilla antennas is provided through the host country agreement, which usually provides approximately 220 hours in total each semester. This is used for both single dish (typically 180 hours per semester) and LBA (typically 40 hours per semester) use. Tidbinbilla proposals remain active for one year. All observations are taken in a service mode when scheduling permits (i.e., the proposer does not need to be present and is not involved in the actual observing). Successful proposals require the submission of a source list with accurate target and calibrator positions.

The Pulsar Backend and the Radio Astronomy Spectrometer are available for successful merit-based proposals. The new Radio Astronomy Users Guide provides a basic outline of the capabilities of both backends. The spectrometer is capable of up to 16 IF products, with up to 32,768 spectral channels, each with 1GHz bandwidth. More detailed documentation about these backends, including details of configuration files, can be found in Virkler et al. 2020, ApJS, 251, 1 (preprint here).

The 70-m antenna is equipped with 2.3, 8.4 and 22 GHz receivers and 34-m antennas are equipped with 2.3, 8.4, 26 and 32 GHz receivers. The 1.6 GHz receiver on the 70-m antenna will not be available until 2024. The 70-m antenna will be on maintenance 19/02/2023 to 19/05/2023. The pointing performance of the 70-m is adequate for observations at the three lowest frequencies (1.6, 2.3 and 8.4 GHz) with no additional calibration, but observations at 22-GHz require a small overhead (~10% of observing time) for determining pointing corrections using bright AGN near the target of interest. It should be noted that the 22 GHz system is the most sensitive in the southern hemisphere, covering 18.0 to 26.5 GHz with a system temperature of 60 Jy. The 34-m antennas are equipped with 2.3, 8.4, 26 and 32 GHz receivers. The 8.4 GHz and 22 GHz systems are well-suited for radio recombination line observations. For large area spectral line mapping projects an On-the-Fly mapping mode is available.

Full details of available frequency coverage and other technical information are available from the Tidbinbilla Information web page. (See also the NASA Deep Space Communication Complex web pages.) An on-line sensitivity calculator is available to assist in proposal preparation.

For the latest information of availability please refer to the Tidbinbilla website, or contact Shinji Horiuchi (Shinji.Horiuchi [at] csiro.au).

Long Baseline Array

For the 2023OCT semester, the Long Baseline Array (LBA) will use the Australia Telescope Compact Array and the Parkes and Mopra radio telescopes, together with the Hobart and Ceduna and the AuScope Yarragadee and Katherine 12-m antennas operated by the University of Tasmania. It is anticipated that ongoing use of Warkworth Observatory 12m and 30m antennas may be possible around their other commitments. The Warkworth 12m can observe at 13 and 3cm, and the Warkworth 30-m telescope can observe at 6.7 and on a best-efforts basis at 4.8 and 8.4 GHz: these can be requested but their availability cannot be guaranteed. The Hartebeesthoek 26-m or 15-m telescopes may also be available. All telescope availability is subject to other commitments - scheduling is done on a best effort basis. A limited amount of time may be available with the Tidbinbilla 70-m antenna (although, as noted above, the 1.6 GHz capability of the 70m is not expected to be reinstated until 2024) or one of the 34-m antennas. For the 2023OCT semester, ASKAP will not be available for VLBI. The AuScope antennas are undergoing a receiver upgrade from their original S/X (2/8 GHz) receivers. Katherine and Hobart have wideband 2--14 GHz receivers and Yarragadee is expected to be upgraded in early 2023. Commissioning of the BIGCAT backend at the ATCA, and the Cryo-PAF receiver at Parkes, may limit the availability, or capability of these telescopes for some months. This in turn, may reduce the number of LBA blocks to be scheduled in 2023OCT. 

During the 2023OCT semester some LBA time may be scheduled at the same time as a European VLBI Network (EVN) session, opening the possibility of joint LBA/EVN observations. The easternmost stations of the EVN are in a similar longitude range to the LBA telescopes, and for sources in equatorial regions, baselines to western European stations are also achievable. Proposals for joint LBA/EVN observations must be submitted separately to both the LBA and EVN at their respective deadlines. Similarly, co-observing with the East Asian VLBI Network is possible, via proposals to both networks.

It is now possible to operate the ATCA in hybrid mode where one frequency chain is setup in VLBI mode and the other frequency chain in ATCA continuum mode (2 GHz bandwidth at 1 MHz resolution). Proposers should explicitly request this mode if they wish to use it, and provide additional scientific justification.

Constraints on Parkes receiver changes impose limits on the frequency of LBA observations with Parkes. Once the Cryo-PAF (700-1950 MHz) is installed alongside the UWL (700 MHz to 4 GHz) receiver, observations at higher frequencies will entail removing one or other of these large receiver packages. This is unlikely to be done more than once per semester. Observations with Parkes at 8.4 and 22 GHz may be possible: other frequencies may be requested but are less likely, and will be available less frequently.

The Parkes UWL and AuScope Katherine and Hobart telescopes produce linear polarisations. There has been some success in converting to circular polarisations post-correlation, but experience is still be gained in this approach and it is not yet 100% reliable.

LBA proposers are reminded that a member (or members) of the proposal team will be required to assist with the VLBI observing on the ATNF telescopes. Please ensure that a member of the proposal team will be able to help. Note that due to logistical constraints the VLBI schedule usually is released only a few weeks before observing, so the observer will need to be qualified for remote observing with Parkes and ATCA. New observers are able to be trained remotely prior to the LBA session.

Telescopes outside the core LBA may be also requested for special observations. Specific system availability may be dependent on availability at individual antennas. Sources close to the equator may benefit from including telescopes from Asia. No formal mechanism is currently available for requesting time and all such telescopes need to be negotiated on a case-by-base basis. Phil Edwards can assist with this process.

For more details consult the ATNF VLBI webpages.

A Novices Guide is available for potential first-time users from the VLBI webpage.

Proposers can use the EVN planning tool, which includes the LBA telescopes. Proposers may also contact Phil Edwards (details below) with any questions related to sensitivity calculations for LBA observations.

The current capabilities of the LBA are briefly outlined below:

  • The disk-based recording system is used for all recorded VLBI observations and data rates (up to 1 Gbps) can be achieved at most stations.
  • All recorded observations will be correlated with the DiFX software correlator. The software correlator is capable of correlating the high data rate observations at high spectral resolution with arbitrary correlator integration times.

User support is available, including assistance with proposal preparation, scheduling, observer training and data reduction.

A bit rate of 256 Mbps (2x16MHz bandwidth in 2 polarisations, with 2 bit digitisation and Nyquist sampling) can be sustained at all LBA telescopes and is the standard observing mode. Observations requesting higher bit rates will need to include a clear justification for the requested rate. Potential users must consult the VLBI National Facilities capabilities .

For more information contact the LBA System Scientist, Phil Edwards (Philip.Edwards [at] csiro.au).

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