The Mauritius Radio Telescope (MRT) images show systematics in the positional errors of sources when compared to source positions in the Molonglo Reference Catalogue (MRC). We have applied two-dimensional homography to correct positional errors in the image domain and avoid re-processing the visibility data. Positions of bright (above 15-σ) sources, common to MRT and MRC catalogues, are used to set up an over-determined system to solve for the 2-D homography matrix. After correction, the errors are found to be within 10% of the beamwidth for these bright sources and the systematics are eliminated from the images.
Cite
@article{arxiv.0905.0880,
title = {Homography-Based Correction of Positional Errors in MRT Survey},
author = {Arvind Nayak and Soobash Daiboo and N. Udaya Shankar},
journal= {arXiv preprint arXiv:0905.0880},
year = {2009}
}
Comments
4 pages, 4 figures, The Low-Frequency Radio Universe, Proceedings of a conference held at NCRA-TIFR, Pune, 8-12 December 2008, ASP Conference Series, Vol. 407, 2009, Eds: D.J. Saikia, D.A. Green, Y. Gupta and T. Venturi