Having an accurate calibration method is crucial for any scientific research done by a radio telescope. The next generation radio telescopes such as the Square Kilometre Array (SKA) will have a large number of receivers which will produce exabytes of data per day. In this paper we propose new direction-dependent and independent calibration algorithms that, while requiring much less storage during calibration, converge very fast. The calibration problem can be formulated as a non-linear least square optimization problem. We show that combining a block-LDU decomposition with Gauss-Newton iterations produces systems of equations with convergent matrices. This allows significant reduction in complexity per iteration and very fast converging algorithms. We also discuss extensions to direction-dependent calibration. The proposed algorithms are evaluated using simulations.
@article{arxiv.1803.05707,
title = {Efficient Calibration of Radio Interferometers Using Block LDU Decomposition},
author = {Ahmad Mouri Sardarabadi and Alle-Jan van der Veen and Léon V. E. Koopmans},
journal= {arXiv preprint arXiv:1803.05707},
year = {2018}
}