ANSAS- A Low Frequency Imaging Spectrometre using Aperture Synthesis

Abstract

The system development of DLR’s ANSAS (Abbil¬dendes Niederfrequenz-Spektrometer mit Apertursynthese) offers the combination of high-resolution aperture synthesis imaging with spectral sensing. The aperture synthesis principal can produce a high resolution snapshot image with a highly thinned array without mechanical movement of an antenna system. The frequency range of 1.4 to 7 GHz allows a high penetration depth in order to extract information about the surface and material of observed objects. Another advantage of that combination, i.e. a higher spatial resolution at higher frequencies and a higher penetration at lower frequencies, can enhance the overall imaging capability using combined processing for the image reconstruction. In this paper the experimental system ANSAS is presented, the setup and receiver assembly is outlined, and some imaging results using the developed electronics on a two-element interferometer showing the capabilities of the concept are illustrated.