Interferometric radiometer

Abstract

A radiometer (100) uses the fringe pattern of an interferometer (110) to scan a scene to produce a time record from which a high-resolution radio frequency, or other radiation, distribution of the scene can be reconstructed. A matched filter (120), or other means, transforms the time record according to a function of a signature of the determinable scanning motion relative to the fringe pattern. For many applications, the modulation transfer function (123) of an included matched filter is the complex conjugate of the Fourier transform of the signature that would be produced by a constant point emitter scanned by the lobes of the interferometer fringe pattern. Two-dimensional reconstructions may be provided for by multiple scans at different orientations. Alternatively, frequency scanning or another scanning technique can provide resolution orthogonal to the fringe pattern scanning motion. Focused distributions of multiple scenes and complex scanning motions are provided by appropriate selections of one or more signatures to process a given time record.