ASKAP team gear up for another big year

Much has been happening for the ASKAP team over the past few months.

The team has been working on a redesign to improve efficiency and performance of the phased array feed (PAF) receivers.

The Australian Square Kilometre Array Pathfinder or ASKAP was designed to be a high-speed survey instrument with high dynamic range. It requires an extremely wide field-of-view interferometer with PAFs consisting of 188 elements in each of two polarisations as the focal plane detectors.

The team have improved the checkerboard geometry of the PAFs, upgraded to signal transmission using RFoF (radio frequency over fibre) and digitally sampled the RF signal at the recently built Murchison Radio-astronomy Observatory (MRO) Control Building.

Enhancements to the ASKAP’s PAF receiver designs have progressed under the ASKAP Design Enhancements (ADE) project. The ADE program was created to improve efficiency and performance of the telescope across the ASKAP band.

System verification tests on three ASKAP antennas with the PAF technology demonstrated successful phase closure. The tests demonstrated proper functioning of the antennas and their electronic systems. It also calibrated the antennas in preparation for interferometry.

Following these tests, the ASKAP antennas were able to provide their first preliminary images. The source field was centred on the radio galaxy PKS 1934-638.

The images were created by the beamformer subsystem capturing 16 single 1 MHz channels, with the raw data correlated in software to form visibilities which were imaged by ASKAPsoft.

This year the project will move into the engineering and scientific commissioning phases of development.

The recently announced $18.8 million government funding will help with the ASKAP and the overall development of the international Square Kilometre Array (SKA) project, set for construction in 2016.

The ASKAP team will be commissioning another three antennas installed with PAFs to make up the Boolardy Engineering Test Array - a six-antenna engineering test array.

For a live view of the ASKAP antennas in action and for more information, visit the CSIRO website.