ASKAP Commissioning News

The construction of ASKAP is nearing completion with 24 antennas having been handed over for commissioning and integration into the array. The remaining antennas await installation of their digital processing systems, scheduled to occur mid-2018. Delivery of ASKAP's capabilities to the astronomical community will happen in staged "array releases" of increasing scope. 

The next major milestone will be array release 3, which consists of 18 antennas, 288 MHz of bandwidth and for the first time, the ability to exchange bandwidth for frequency resolution (known as "zoom modes" within the community). Array release 3 will also offer the longest baselines (and therefore highest image resolution) to astronomers for the first time. Zoom modes will enable studies of neutral Hydrogen and other spectral lines within the Milky Way, providing a more detailed picture of gas dynamics and stellar feedback.

Array release 4 is the full ASKAP system with 36 antennas and this is currently scheduled for release on a shared-risk basis in early 2019.

One of the major challenges faced by ASKAP is the desire to begin survey operations early in the life cycle of the telescope. Most radio telescopes spend the first few years of operation conducting smaller-scale projects while the system reaches the level of maturity required to conduct large-scale all-sky surveys (which represent a major investment in time).

ASKAP will be expected to perform large-scale surveys very early in its operational lifespan, requiring particular attention to detail during commissioning. To gain experience with survey operations, we intend to conduct a series of "pilot surveys", which will be designed to investigate specific targets that provide a good test of the telescope's characteristics (sensitivity, dynamic range, calibration stability, etc.).

At a recent meeting of ASKAP's science team principal investigators we described the planned array release schedule including readiness to take 36-antenna survey data in some form in early 2019.  There was also discussion of plans to review the original survey proposals. Given the time that has passed since the original call for proposals there was consensus that a reassessment of the survey scientific goals and technical feasibility is required at some point in the near future, though the timing of this process is still under consideration.

The scientific climate has changed significantly (particularly in the field of transient detection) during this time. As we move towards array release 4, it will be important to maintain close ties with the science teams and we expect to host more of these discussions every few months. This will allow us to prioritise development of key systems (such as the science data pipeline software) based on up-to-date science requirements