Synthetic aperture radio telescopes

Next-generation radio telescopes will be much larger, more sensitive, have a much larger observation bandwidth, and will be capable of pointing multiple beams simultaneously. Obtaining the sensitivity, resolution, and dynamic range supported by the receivers requires the development of new signal processing techniques for array and atmospheric calibration as well as new imaging techniques that are both more accurate and computationally efficient since data volumes will be much larger. This article provides an overview of existing image formation techniques and outlines some of the directions needed for information extraction from future radio telescopes. We describe the imaging process from measurement equation until deconvolution, both as a Fourier inversion problem and as an array processing estimation problem. The latter formulation enables the development of more advanced techniques based on state-of-the-art array processing. We also demonstrate the techniques on simulated and measured radio telescope data.