Abstract
The stations of the mid-frequency aperture array (MFAA) envisaged for the second phase of the Square Kilometer Array (SKA) are expected to consist of order 103 to 104 receive paths. This will make calibration procedures based on the array covariance matrix computationally expensive. Recently, self-holography (SH) was proposed to overcome this issue. This method assumes that the signal from the chosen calibration source can be sufficiently well isolated. We study the signal-to-interference ratio (SIR) of the most suitable calibration source over a sidereal day for a representative MFAA station located on the SKA site in South Africa. We find that an SIR of 20 dB or higher is achievable over (most of) a sidereal day. This is well above the 11.5 dB needed to keep the beamformer efficiency after calibration above 99%. We therefore conclude that SH is a promising candidate for station calibration of the MFAA stations.
Highlights
The Square Kilometer Array (SKA) science book[1] provides a broad overview of the science enabled by the SKA
A realistic sky model was simulated for an array that is based on the preliminary specifications of the mid-frequency aperture array transient and intensitymapping system (MANTIS)
The signal-to-interference ratio (SIR) was analyzed over a full sidereal day for a station placed at the SKA site in South Africa
Summary
The Square Kilometer Array (SKA) science book[1] provides a broad overview of the science enabled by the SKA. As the size of the individual antennas scales proportional to the observed wavelength, the number of receive paths involved rises sharply with frequency With current technology, this makes aperture arrays viable up to L-band. We use the design of the MFAA science demonstrator dubbed mid-frequency aperture array transient and intensitymapping system (MANTIS)[10] and a realistic sky model derived from the National Radio Astronomy Observatory Very Large Array Sky Survey (NVSS),[17] the SUMSS,[18] and the Haslam map.[19] We demonstrate that the proposed MANTIS stations are large enough to provide sufficient spatial selectivity to isolate a suitable calibration source at any sidereal time when the stations are located on the South-African SKA site. We discuss the results from the simulations and present our conclusions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
