Problems Concerning Holographic Imaging at Microwave Frequencies

This paper shows the results of holographic imaging experiments at the 35 GHz band. The hologram was reduced by an inserted lens and the images were reconstructed by computer. The effects of changes in both, the hologram-structure, i.e. hologram-size and sampling, and in the measured amplitude and phase values by quantization upon the reconstructed image are shown. The disturbance of the images, i.e. the appearance of ´hot spots´, caused by the imaging of three-dimensional metallic objects is reduced by aspect-angle diversity or by frequency diversity. Applying two different reference-phase measurements, the limitations of the object´s translational and rotational movements during the hologram recording are given.