ELIMINATING SOLAR INTERFERENCE IN RADIO INTERFEROMETRIC SPECTROMETRY

The presence of a strong source, such as the sun or Cassiopeia A, in t he distant sidelobes of a radio telescope can limit the image quality achieved with these observations. Conventional methods of subtracting out the response of these sources have limited success. In part this i s because the instrumental response a large distance from the pointing centre is generally poorly understood and time variable. In the case of the sun it is also because the sun's complex and variable nature. W e present an approach, based on a continuum subtraction technique, whi ch can substantially reduce the interference caused by such sources fo r spectral line experiments. We present an observation where the solar interference has been reduced by a substantial amount.