Phase calibration of arrays at optical and millimeter wavelengths

Aperture synthesis experiments have been performed at optical and millimeter wavelengths with an array designed for self-calibration by means of redundant spacings calibration. This calibration technique, which works at all electromagnetic wavelengths, allows the removal of phase errors caused by antenna positional errors, local oscillator phase shifts, and medium-induced transmission phase errors in a single snapshot without requiring that a model of the source be built. Results are presented that demonstrate the removal of phase errors from optical and passive millimeter-wave images by use of redundant spacings calibration with one- and two-point sources. It is shown that optical simulations provide a valuable method for determining the performance of arrays at millimeter wavelengths.