  This paper is the first of a series reporting the results of the Australia
Telescope ESO Slice Project (ATESP) radio survey obtained at 1400 MHz with the
Australia Telescope Compact Array (ATCA) close to the South Galactic Pole (SGP)
over the region covered by the ESO Slice Project (ESP) galaxy redshift survey
(decl. ~ -40 degr). The survey consists of 16 radio mosaics with ~8"x14"
resolution and uniform sensitivity (1sigma noise level ~79 microJy) over an
area of ~26 sq.degrees. Here we present the design of the survey, we describe
the mosaic observing technique which was used to obtain an optimal combination
of uniform and high sensitivity over the whole area, and the data reduction:
the problems encountered and the solutions adopted.
