ATNF Telescope Status for 2020OCT

All ATNF Telescope Applications for 2020OCT must be submitted using OPAL.

Cover sheets from previous semesters should be re-loaded into the cover sheets editor and carefully re-checked before (re-)submitting a proposal.

Note that an abbreviated version of proposal team details are now listed at the end of the proposal as part of a trial to reduce unconscious bias
during the review process.

The deadline for all proposals is 07:00 UT (17:00 Sydney local time), Tuesday, 16 June 2020.

 

For 2020OCT, ATNF proposals will be accepted for the:

  • Australia Telescope Compact Array;
  • Parkes 64m telescope;
  • Tidbinbilla 70-m (DSS-43) and 34-m (DSS-34) antennas; and
  • Long Baseline Array.

What's new in 2020OCT?

  • As a result of restrictions due to the COVID-19 pandemic, observations with ATNF telescopes must currently be carried out remotely. New observing teams will be able to be trained remotely while these restrictions are in place. All observers will be notified whenever changes are made to travel restrictions and when observing from the Marsfield or Perth Science Operations Centres is possible again.
  • OPAL will now, in generating the full proposal, list an abbreviated version of proposal team details at the end of the proposal as part of a trial to reduce unconscious bias during the review process.
  • Parkes: Please refer to the Parkes section below for details about plans to rationalise the receiver fleet subject to proposal pressure.
  • 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. 
  • Tidbinbilla: The Tidbinbilla 70m antenna will be off-line for maintenance until January 2021.
  • Note that Large Proposals (>400 hours over the lifetime of the project) are now required to include in their justifications a section describing team roles/contributions (see the OPAL Users Guide).

 


General Information

Target of Opportunity proposals can be submitted at any 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. As noted above, Large Proposals are now required to include in their justifications a section describing team roles/contributions.

New users are advised to read the information on the ATNF Scientific Support of Facilities. This web page explains the different levels of support provided to proposers and observers.

Observing support and remote observing qualification requirements were changed in February 2015 and are described in the ATNF observing support model.

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

For further information contact Phil Edwards (Philip.Edwards [at] csiro.au).


 

ATCA picture and link
 

 

ATCA Observing

As a result of restrictions due to the COVID-19 pandemic, observing with ATCA must currently be done remotely. New observers are able to be trained remotely. All observers will be notified whenever changes are made to travel restrictions and when observing from Marsfield and the Narrabri site is again possible. (After travel restrictions have been lifted, the previous requirements for observing will be continued: The default location for observing with the ATCA is the Marsfield Science Operations Centre (SOC). All observers who require support in scheduling and/or observing, or those who need to be requalified as remote observers, must visit the SOC for their observations. 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. Remote observing from other locations is permitted for suitably qualified observers. The Narrabri observatory is considered a remote observing site with regard to support levels for normal observations.)

ATCA Legacy Projects

It is anticipated ATCA Legacy Projects. will continue to be allocated 25%--35% of observing time on the ATCA in 2020OCT. There is no proprietary period for the raw data from Legacy Projects. This is to maximise the scientific outcomes from the large fraction of observatory time they represent, and to enable timely follow-on observations.

Array configurations

For 2020OCT, the array configurations 6A, 6D, 1.5A, 1.5D, 750B, 750C, EW367, EW352 and H168 will be offered. The 2020APR semester will end in 6B array and so this may be continued for the first weeks of 2020OCT; this does not preclude it from being scheduled again later in the semester. 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 2020OCT 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. Pulsar binning mode: The normal 2048 x 1 MHz continuum band is supplied for each IF band and in addition, for each IF, a time-binned IF band with 512 x 4 MHz channels and 32 time bins across the period of the pulsar. A minimum bin time of 110 micro-seconds is possible, allowing 32 bins across a 3.5 milli-second pulsar period. All observers who want to use this mode are responsible for providing their own timing ephemerides for their targets; the observatory cannot provide these for you. Ephemerides must be supplied in the tempo2 predictor format.
  6. High time-resolution mode: The normal 2048 x 1 MHz continuum band is supplied for each IF band and in addition, for each IF, a time-binned IF band with 512 x 4 MHz channels and either 128 or 32 time bins across the correlator cycle period (normally 10 seconds, but can be routinely set as low as 2 seconds).
  7. 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 CASS, 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 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.

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 2020 will be near a R.A. of 2h28m and declination of +14d09m. 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 2020OCT. Details of the system are available at the WVR webpage.

Further information


 

Parkes picture and link

 

 

Receiver availability

With the high demand for the Ultra-Wideband Low frequency receiver (UWL), the declining demand for the 20cm Multibeam (MB) and the successful funding proposal for the Cryogenically Cooled Phased Array Feed ('CryoPAF'), we are proposing to decommission the MB, subject to proposal pressure. By removing the MB we could install two high frequency receivers in its place, and in due course remove them to expedite CryoPAF commissioning. This would mean that the MB would be available for ~ 1month at the start of the 2020OCT semester and then be removed for the installation of the 13mm and Mars receivers. The Mars receiver could potentially be swapped for the 'Old Meth' receiver for limited use (e.g., a VLBI week). Furthermore, with the initial exception of the Galileo receiver, we propose to formally decommission other older receivers in the Parkes receiver fleet. Further details can be found in the linked document here and ATUC presentation here.  This receiver rationalisation is subject to the proposal pressure of this current call (and its subsequent assessment by the Time Allocation Committee) as well as feedback from the user community.

Backend Availability

MEDUSA is a GPU based backend, which is for use with the UWL, and details of the available modes can be found in the users guide here (with other modes driven by proposals, acknowledging shared risk development). It is intended that this backend will cater for all receivers in the future. For those intending to use the UWL please include details of the backend capabilities required. 

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. 

Other legacy backends available are:

  • DFB4, a digital filterbank, is available for pulsar, spectral line (simple and time-binning), continuum and polarisation (full Stokes) studies. The number of available frequency channels (512 to 8192) allows spectral behaviour analysis and RFI flagging. In combination with either circular or linear feeds they can be used for Stokes Q & U or Stokes V observations respectively. A time resolution down to 0.25s is achievable in time-binning mode allowing fast scanning options (though note in this mode the maximum number of channels is 4096).
  • CASPSR, a coherent de-dispersion pulsar backend developed by Swinburne University of Technology, is available on a shared-risk basis.
  • BPSR/HIPSR is available as a 13-beam digital filterbank on a similar shared-risk basis until the MB is decommissioned. Two spectral line modes are provided by HIPSR. These modes are (i) a bandwidth of 400 MHz on all 13 beams, with 8192 spectral channels per product and (ii) a bandwidth of 200 MHz on all 13 beams, with 16384 spectral channels per product.
  • VLBI backends (Mark5B, LBADR) are available for non-LBA VLBI and single dish voltage capture, although are due to be phased out during the 2020OCT semester (with VLBI data capture being obtained via the MEDUSA backend). This allows you to capture up to 2 x 64 MHz or 8x16 MHz dual polarisation bands with 2 bit sampled raw voltage output, or 2x16 MHz dual polarisation bands with 8 bit sampled voltage. If you choose to use Parkes in this mode, without requesting any other LBA station or VLBI correlation by CASS, you only need to write a Parkes proposal. These modes have restrictions however, and proposers who are interested in using this must contact the LBA System scientist 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). To manage the archiving process efficiently, it is necessary to know the expected data volume for projects with Terabyte-scale data requirements, and observations will be scheduled accordingly. 

The cover sheet for Parkes proposals specifically requests this information for projects that are likely to gather more than 0.5 Terabytes of data per hour. Further points to note are:

  1. Individual files can not be larger than 100 GB for pulsar data. The output data files from the UWL are automatically split to ensure this. Observations with DFB4 require manual choice of the file splitting time.

  2. The maximum data rate is limited to 20 Gb/s

  3. If you expect to produce more than 5TB in total during the semester, or more than 0.5TBs per hour, then please state your data requirements in your submission, noting that observers should adhere to the observing set-up described in their proposal. If you exceed your stated data rate/volume then we may need to delete the data files before you are able to access them and they will not be archived. 

To calculate data volumes with the UWL:

  • 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)
  • Tdump = 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.

Telescope Control Software

DHAGU is now the primary control software interface for use with the UWL receiver. It is based on the system used by ASKAP, the Telescope Operation System. It does not currently interface with DFB4 or CASPSR. The traditional system, Telescope Control Software (TCS), will continue to be used for DFB4 and CASPSR observations. Documentation is available for the new control software from the links tab within DHAGU and in the users guide

Contracted telescope usage

Breakthrough Listen will continue to be allocated 25% of Parkes observing time, with the program having commenced in the 2016OCT 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 continuing their 25% of telescope time allocation, so too does an agreement with an NAOC FAST collaboration. Initally for ~18% of time over a 3 year period, it has since been extended for a smaller allocation of ~200 hrs per semester. 

Observing Information

Remote observing with the Parkes telescope is the default mode of observing during the COVID-19 period. If travel restrictions are relaxed during the 2020OCT semester, then it will be permissible 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 is not fully supported (e.g. there is no onsite accommodation), we do encourage site visits during working hours for those interested (as and when COVID-19 travel restrictions are removed).

It is expected that proposal teams will be scientifically self-sufficient, with a member of each team being designated the Project Expert and being the first point of contact (remotely) for questions relating to the observations after work hours. Inexperienced teams are encouraged to seek experienced collaborators. First time observers will be trained remotely, but will require an experienced observer or the Project Expert to assist with their first observations. All Parkes proposal teams are asked to nominate on the cover sheets of their proposal the member(s) in their team who will be (or will be trained to be) the Project Expert and who will be the first point of contact after hours. Please ensure that the Project Expert is aware of their role and of the times and dates that they may be called upon. When COVID-19 travel restrictions are removed, observers at the SOC are able to receive assistance from staff (during business hours) with their observing. Remote assistance can be sought during working hours from the Parkes mattermost channel (please ask the System Scientist for access). 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 the Parkes System Scientist, Jimi Green (James.Green [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 picture and link

 

 

 

In the 2020OCT semester the 70-m and 34-m antennas at Tidbinbilla will have some availability for single-dish use. The 70-m antenna will be off-line for a prolonged maintenance and upgrade period and is not expected to be available again until January 2021. 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. 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 12 IF products, with up to 32,768 spectral channels, each with 1GHz bandwidth. More detailed documentation about these backends, including details of configuration files, are currently in preparation.

The 70-m antenna is equipped with 1.6, 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 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 system is well-suited for radio recombination line observations.

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 Jimi Green (James.Green [at] csiro.au).


 

LBA picture and link

 

 

 

For 2020OCT semester, the Long Baseline Array (LBA) will use the Compact Array and Parkes radio telescope, together with the Hobart and Ceduna antennas operated by the University of Tasmania. In addition, the Warkworth 12-m telescope, operated by the Auckland University of Technology, is routinely available at 13 and 3cm, and on occasions at 20cm, and the Warkworth 30-m telescope is available at 6.7 and 8.4 GHz and on a best-efforts basis at 4.8 GHz. A limited amount of time may be available with the Tidbinbilla 70-m antenna (although, as noted in the Tidbinbilla section of this Call, the 70-m will be off-line until January 2021) or one of the 34-m antennas. The availability of the Mopra telescope for 2020OCT is currently unclear: it may be included in the requested array, but with the understanding that it may not be scheduled. For the 2020OCT semester ASKAP will be unavailable for VLBI. The AuScope Yarragadee and Katherine 12-m antennas may also be available at 13cm or 3cm subject to their availability. The Hartebeesthoek 26-m or 15-m telescopes may also be available subject to its other commitments.

It is planned in the 2020OCT semester to schedule some LBA time 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.

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, however note that the new UWL receiver means Parkes can be included in VLBI observations between 700 MHz and 4 GHz at almost any time.

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 release only a few weeks before observing, so the observer will need to be qualified for remote observing with Parkes and ATCA, or able to travel to the SOC in Sydney before the LBA session in time to be trained.

Other telescopes may be also requested for special observations. Specific system availability may be dependent on availability at individual antennas. For details consult the ATNF VLBI webpages.

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

The LBA VLBI sensitivity calculator no-longer seems to run on any modern web browser. Efforts are underway to develop a new version of the calculator. Until that time proposers may contact Chris Phillips (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.
  • Real-time e-VLBI observations are possible -- contact Chris Phillips (details below) if you are interested in this mode.

User support is available, including assistance with proposal preparation, scheduling, observing 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, Chris Phillips (Chris.Phillips [at] csiro.au).

 

 

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