Rupert N. Anderton

High-performance passive millimeter-wave imaging

We discuss the current status of passive millimeter-wave radiometry as a thermal imaging technique. The major problems are poor spatial resolution and slow response time. Techniques for overcoming these difficulties are identified, including the use of aperture synthesis, multichannel receivers, correlation, and inverse transform techniques. A comparison is made with infrared imaging.

Advances in passive millimeter wave imaging

The status of passive millimeter wave radiometry as a thermal imaging technique will be discussed. Methods will be identified for overcoming the usual difficulties of poor spatial resolution and slow response time. High quality images will be presented to demonstrate the potential of this technology.

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.