Three-dimensional image-construction technique and its application to coherent microwave diagnostics

A 3-dimensional image-construction technique for long-wavelength imaging by combining different views of an object is proposed. It is appropriate for remote scanning in which the diffraction fields of the object are recorded rather than projections. The approach uses additive or multiplicative combination of the data from each view of the object, yet the data-acquisition and data-processing requirements are modest. It is demonstrated by computer simulation and by microwave experiment that definition of very small 3-dimensional object configurations composed of individual scatterers is not limited by the depth of focus of a single recording aperture. The selection of planes from the 3-dimensional image array with improved resolution and suppressed noise extends the capability of microwave diagnostics which are essentially 2-dimensional at the present time.