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Description
We have used the Very Large Array (VLA) in C configuration to carry out a sensitive 20-cm radio survey of regions of the sky that have been surveyed in the far-infrared (FIR) over the wavelength range 5-200{mu}m with ISO (Infrared Space Observatory) as part of the European Large-Area ISO Survey (ELAIS). As usual in surveys based on a relatively small number of overlapping VLA pointings, the flux limit varies over the area surveyed: from a 5{sigma} limit of 0.135mJy over an area of 0.12deg^2^ to 1.15mJy or better over the whole region covered of 4.22deg^2^. In this paper we present the complete radio catalogue of 867 sources, 428 of which form a complete sample in the flux range 0.2-1.0mJy. These regions of the sky have previously been surveyed to shallower flux limits at 20cm with the VLA as part of the VLA D configuration NVSS (full width at half-maximum, FWHM=45arcsec) and VLA B configuration FIRST (FWHM=5arcsec) surveys. Our whole survey has a nominal 5{sigma} flux limit a factor of 2 below that of the NVSS; 3.4deg^2^ of the survey reaches the nominal flux limit of the FIRST survey and 1.5deg^2^ reaches 0.25mJy, a factor of 4 below the nominal FIRST survey limit. In addition, our survey is at a resolution intermediate between the two surveys and thus is well suited for a comparison of the reliability and resolution-dependent surface brightness effects that affect interferometric radio surveys. We have carried out a detailed comparison of our own survey and these two independent surveys in order to assess the reliability and completeness of each. Considering the whole sample, we found that to the 5{sigma} nominal limits of 2.3 and 1.0mJy, respectively, the NVSS and FIRST surveys have a completeness of 96^+2^_-3_ and 89^+2^_-3_ per cent and a reliability of 99^+1^_-2_ and 94^+2^_-2_ per cent.
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