Title: Radio Astronomy Image Formation in the SKA Era
Abstract: The Square Kilometre Array (SKA) is a new generation radio telescope, planned to be operational in 2025. SKA will consist of massive numbers dish antennas as well as antenna arrays. One of the key science drivers is the discovery of the faint ‘21-cm signal’ from neutral hydrogen in the infant Universe. Characterising it would provide insight on the early Universe and the formation of the first stars, galaxies, black holes and intergalactic gas. However, detection of the 21-cm signal is extremely difficult because it is masked by emissions from much brighter radioemitting sources (e.g. the Milky Way), up to a million times stronger than the 21-cm signal. Moreover, the received data is corrupted by the time-varying ionosphere, the radio receivers, and man-made interference signals, while also the required exabyte data volumes provide enormous challenges. Thus, significant signal processing efforts are required in the areas of calibration, image formation, and interference detection/cancellation, while the high-performance algorithms should be “simple” and efficient to implement on parallel or distributed compute platforms.
The talk will discuss the general design of SKA, highlight the computational challenges, and present in more detail the image formation problem, a large-scale inverse problem that is inherently ill-posed. Among various possible regularizations that encourage sparsity of the solution, we present one promising new approach related to Sparse Bayesian Learning.
Short Bio: Alle-Jan van der Veen is a Full Professor in Signal Processing at TU Delft, The Netherlands, and Fellow of the IEEE and of EURASIP. He was chairman of the IEEE SPS Signal Processing for Communications Technical Committee, Editor-in-Chief of IEEE Signal Processing Letters, Editor-in-Chief of IEEE Transactions on Signal Processing, and Chairman of the IEEE SPS Fellow Reference Committee. At present, he is chairman of the IEEE SPS Signal Processing Methods and Techniques Technical Committee, chairman of the IEEE Kilby Medal selection committee, and Director of Publications of EURASIP. His research interests are in the general area of system theory applied to signal processing, and in particular algebraic methods for array signal processing, with applications to wireless communications and radio astronomy.