Title:	Ionospheric modelling using GPS to Calibrate the MWA. I: Comparison of first order Ionospheric effects between GPS Models and MWA observations
Authors:	Arora, B. S. Morgan, J. Deshpande, A.A. Prabu, T. Udaya Shankar, N. Srivani, K.S. Subrahmanyan, Ravi +35 Co-authors
Issue Date:	Aug-2015
Publisher:	Cambridge University Press for Astronomical Society of Australia
Citation:	Publications of the Astronomical Society of Australia,2015,Vol.32, e029
Abstract:	We compare first-order (refractive) ionospheric effects seen by the MWA with the ionosphere as inferred from GPS data. The first-order ionosphere manifests itself as a bulk position shift of the observed sources across an MWA field of view. These effects can be computed from global ionosphere maps provided by GPS analysis centres, namely the CODE. However, for precision radio astronomy applications, data from local GPS networks needs to be incorporated into ionospheric modelling. For GPS observations, the ionospheric parameters are biased by GPS receiver instrument delays, among other effects, also known as receiver DCBs. The receiver DCBs need to be estimated for any non-CODE GPS station used for ionosphere modelling. In this work, single GPS station-based ionospheric modelling is performed at a time resolution of 10 min. Also the receiver DCBs are estimated for selected Geoscience Australia GPS receivers, located at Murchison Radio Observatory, Yarragadee, Mount Magnet and Wiluna. The ionospheric gradients estimated from GPS are compared with that inferred from MWA. The ionospheric gradients at all the GPS stations show a correlation with the gradients observed with the MWA. The ionosphere estimates obtained using GPS measurements show promise in terms of providing calibration information for the MWA.
Description:	Restricted Access. An open-access version is available at arXiv.org (one of the alternative locations)
URI:	http://hdl.handle.net/2289/6344
ISSN:	1323-3580 1448-6083(online)
Alternative Location:	http://adsabs.harvard.edu/abs/2015PASA...32...29A http://arxiv.org/abs/1507.01184 http://dx.doi.org/10.1017/pasa.2015.29
Appears in Collections:	Research Papers (A&A)

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