10C survey of radio sources at 15.7 GHz - I. Observing, mapping and source extraction

We have observed an area of ≈27 deg² to an rms noise level of ?0.2 mJy at 15.7 GHz, using the Arcminute Microkelvin Imager Large Array. These observations constitute the most sensitive radio-source survey of any extent (≳0.2 deg²) above 1.4 GHz. This paper presents the techniques employed for observing, mapping and source extraction. We have used a systematic procedure for extracting information and producing source catalogues, from maps with varying noise and uv-coverage. We have performed simulations to test our mapping and source-extraction procedures, and developed methods for identifying extended, overlapping and spurious sources in noisy images. In an accompanying paper, AMI Consortium: Davies et al., the first results from the 10C survey, including the deep 15.7-GHz source count, are presented. We request that any reference to this paper cites 'AMI Consortium: Franzen et al. 2011'.