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D. Ferris

Publications and source records attributed to D. Ferris.

2 recordsLinked to original sources

The Australian Square Kilometre Array Pathfinder: System Architecture and Specifications of the Boolardy Engineering Test Array

This paper describes the system architecture of a newly constructed radio telescope - the Boolardy Engineering Test Array, which is a prototype of the Australian Square Kilometre Array Pathfinder telescope. Phased array feed technology is used to form multiple simultaneous beams per antenna, providing astronomers with unprecedented survey speed. The test array described here is a 6-antenna interferometer, fitted with prototype signal processing hardware capable of forming at least 9 dual-polarisation beams simultaneously, allowing several square degrees to be imaged in a single pointed observation. The main purpose of the test array is to develop beamforming and wide-field calibration methods for use with the full telescope, but it will also be capable of limited early science demonstrations.

astro-ph.IM

Revisited "Cluster-Cluster" VLBI with future multi-beam low frequency radio interferometers

We revisit the "Cluster-Cluster" or multi-view Very-Long-Baseline-Interferometry (VLBI) technique from the perspective of its synergy with the multi-beam features inherent in the Australian Square Kilometer Array Pathfinder (ASKAP)and its potential to improve the outcomes of VLBI observations with ASKAP. We include a list of candidate VLBI sites that already support or can be upgraded to support multi-view VLBI located in Australia and overseas, and which have common visibility with ASKAP. The results of our previous "cluster-cluster" observations at 1.6 GHz demonstrated the advantages of this configuration to calibrate the ionospheric distortions responsible for the loss of positional accuracy at low frequencies, using multiple calibrators in a range between 1 to 6 degrees away from the target. Therefore, we conclude that joint observations of ASKAP with other multi-view sites using "cluster-cluster" techniques would improve the outcomes of the high spatial resolution component of ASKAP applied to astrometric projects, achieving higher precision for many more targets, and with lower detection thresholds. Also very wide-field VLBI mapping becomes a possibility. Looking to the future, this would contribute to the development of new techniques that are relevant for future high resolution observations with the SKA.

astro-ph.IM