ATCA Release notes for 2021OCT
ATCA observing: The default observing location for all ATCA observations is the Science Operations Centre (SOC) at the ATNF headquarters in Marsfield, Sydney. First-time observers are required to observe from the SOC, where they will be supported by the Duty Astronomer (DA) and Operations staff. Observers who wish to travel to the observatory for their observations may do so (although limited space is available at the on-site lodge), but support is limited to that given to any other remote observer.
The Duty Astronomer role is now primarily based at the SOC, although can also be based at the ARRC centre in Perth or at the Paul Wild Observatory for some weeks where no astronomers are expected to observe from the SOC. The DA will be present on-site for first-time observers and be contactable at all times, but may provide support from other locations for remote observers (i.e., remote from the SOC).
The present annual requirement to observe from the SOC in order to be "remote qualified" will be retained for most observers. Regular, competent observers (typically, people observing on at least three separate occasions or for more than 10 days per semester) can extend the time between their return visits by 6 months.
The Marsfield site has a Lodge which is able to provide on-site accommodation for observers and DAs. Please use the new webform to book at least two weeks in advance to ensure a room is available. That webform may also be used to book accommodation at the observatory lodge in Narrabri.
At schedule release, strict restrictions are still in place to combat COVID-19. The latest status will always be shown on the ATCA observing home page, and may change during the semester.
ATCA Legacy Projects: CSIRO Astronomy and Space Science implemented a program of ATCA Legacy Projects starting from the 2016OCT semester. Legacy Projects are large, coherent science investigations, not reproducible by any combination of smaller projects, that generate data of general and lasting importance to the broad astronomy community. More details are available from the Legacy Project webpage. The call for Expressions of Interest proposed that Legacy Projects would be supported at the level of 25% of the available observing time. As there was some uncertainty over the funding of the ATCA into the future, the TAC was advised that ATNF would be willing to support Legacy Projects at a higher level. For this semester, legacy projects have been awarded 516 hours of telescope time, from an available 4392 hours.
The highest priority project C3132, "GAMA Legacy ATCA Southern Survey (GLASS): A Legacy 4cm Survey of the GAMA G23 Field", completed its observations in the 2019OCT semester. The other high-priority project C3157, "Imaging Galaxies Intergalactic and Nearby Environment (IMAGINE)", completed its survey in 2020OCT.
The TAC also recommended that two further projects be supported at a lower priority: C3145, "StarFISH (Star Formation In the Southern Hemisphere)" and C3152, "A Comprehensive ATCA Census of High-Mass Cores." C3145 was the only Legacy project to ask for time this semester, and received 231 hours.
Purchased Telescope Time: This semester there is one project which have purchased telescope time on ATCA: a science project with code C3433, which has bought 36.5 hours of time in early October.
ATCA portal: The portal is a web-based tool that enables the observers to book in advance for observing blocks and to register as the current observer-in-charge. It also provides alerts, contact details, and a improved chat facility over that previously used in the ATCA observing VNC session. More details are available from the ATCA Current Issues webpage and the ATCA User Guide. First-time users should refer to the ATCA Portal Beginners Guide.
Radio Frequency Interference (RFI): There is a strong emitter in the 16cm band in the 2630-2670 MHz range, a previously relatively clear part of the spectrum often used by 16cm-band observers for their delay calibration. Instructions for dealing with this are are available from the ATCA Current Issues webpage. RFI in the 16cm band also causes the sampler statistics to fluctuate, and the automatic attenuator setting often does not work. A set of standard attenuator settings for the 16cm band has been determined and these can be manually set -- see section 3.2.2 of the ATCA User Guide for more details. (If they have been set by a previous observer, it may not be necessary to set them again.)
There is also some RFI in the 15mm band in the frequency ranges 17.7--18.2 GHz, 18.8--19.3 GHz and 19.7--20.2 GHz which arises from a geostationary satellite and is stronger towards equatorial declinations. See the ATCA Current Issues webpage for more information.
RFI in the 16cm band cannot yet be mitigated on-line, but a mode in the correlator allows observers to more easily mask its effect on the diagnostic visibilities, using median averaging. Instructions on how to do this can be found from the ATCA Current Issues webpage.
CABB modes: All current CABB modes will be available for the 2021OCT semester: (1) the 1MHz continuum ("no zooms") mode, (2) the 1MHz zooms mode (1M-0.5k), with up to 16 zoom bands per IF available, (3) the 64MHz mode (64M-32k), which provides 32 channels of 64MHz bandwidth and up to 16 zoom bands (each having 2048 channels across it) in each IF (4) the "hybrid" mode, with 2048 x 1MHz channels in IF1 (and no zooms) and 32 x 64MHz channels in IF2 (with zooms), (5) the pulsar binning mode, (6) the VLBI tied-array mode. See the CABB webpage for more details. CABB mode changes are mostly routine, except for changes to the 1MHz zoom mode, 64 MHz zoom mode, and hybrid mode, which require approximately one hour: this mode change is done by local staff or suitably trained others. In the graphical version of the schedule the requested CABB mode is shown in the top right corner of each block.
NAPA Proposals: A number of NAPA (Non A Priori Assignable) proposals have been submitted for ATCA in 2021OCT. We have a policy for dealing with NAPA over-rides, intended to ensure highly time-critical projects can be scheduled on the telescope. For the 2021OCT semester, any NAPA which received a grade equal to or higher than the grade at which most of the projects got most of their time, will be able to over-ride any scheduled project. For this semester, all of the twenty-eight NAPA projects meet this criteria.
If triggered, observatory staff will discuss with the proposers the best time for the over-ride to occur, which may not necessarily involve any project being displaced. Requests to trigger a NAPA proposal can be made by emailing the ATNF alert group, as described here.
Any observations displaced by a NAPA will be rescheduled if possible, but this is not guaranteed.
There are three NAPA projects that are authorised to use the rapid response service. Rapid response over-rides may occur at any time without staff or observer intervention.
Investigators triggering NAPAs are reminded that claim staking is not permitted under ATNF policy.
In order to minimise the impact of multiple competing triggers to observe the same event, the TAC has recommended that we encourage data sharing between NAPA teams who nominate to observe the same coordinates with the same receiver configuration and observing strategy. Observatory staff will discuss this arrangement with the affected teams should this situation arise.
Green Time: Green time should be requested through the Portal. Instructions for doing this can be found in the "Book" tab in the Portal. Requests for green time can be made at any time during the semester, but the final allocation will not be made until 1 week beforehand.
If you are requesting green time for a project that was not ranked by the TAC for this
semester, please also email Jamie Stevens (
Daylight Saving: Daylight saving in New South Wales will start at 2:00am (AEST) on Sunday, 3rd October 2021, when clocks will be put forward one hour. AEDT is 11 hours ahead of UTC. Daylight saving in New South Wales will end at 3:00am (AEDT) on the first Sunday in April 2022.
- Labour Day (NSW) Monday Oct 4 2021
- Christmas Day (Aus) Saturday Dec 25 2021
- Boxing Day (Aus) Sunday Dec 26 2021
- Christmas Day Additional Day (Aus) Monday Dec 27 2021
- Boxing Day Additional Day (Aus) Tuesday Dec 28 2021
- New Year's Day (Aus) Saturday Jan 1 2022
- New Year's Day Additional Day (Aus) Monday Jan 3 2022
- Australia Day (Aus) Wednesday Jan 26 2022
Version 1 of the schedule was released on 2021 September 1.
Version 2 of the schedule was released on 2021 September 20, which moved C3443 from November to December and shortened a single maintenance block on December 23. No other allocations were modified.
Version 3 of the schedule was released on 2021 September 30, which changed the 1.5C array into 1.5A. This was in response to the failure of a transformer at the west end of the track. If 1.5C array was kept, three antennas would need to run on generator for the duration of the configuration, whereas only one antenna would need to run on generator in the 1.5A array.
Generated: Jamie Stevens (30-sep-2021)