A Single Display for RASCAN 5-frequency 2-polarisation Holographic Radar Scans

The RASCAN holographic radar system has been developed by the Remote Sensing Laboratory of Bauman Moscow Technical University. The present design uses ¯ve frequencies and two polarisations to give 10 distinct images of scan from buried objects. Because of the sinusoidal phase variation of the interference signals, all displays show a complex picture of dark and light phases which vary in a complicated way between di®erent frequencies and polarizations. This is a preliminary investigation into the optimal presentation of the 10 images as a single composite image. The objective is to display as much as possible of the information present in the original image. The solution presented here is to sum the absolute values of the background-corrected amplitude over both the ¯ve frequencies and the two polarizations. The method is justi¯ed using an experiment in which nine US pennies, and 9 metal washers, were buried in sand at increasing depths in the range 0 to 56 mm. The method is illustrated by example images from the fields of civil engineering and mine detection.