ANSAS- A Microwave Imaging Spectrometer - First Measurment Results

Abstract

In the last decades the monitoring of the environment becomes more and more important. In order to understand the geophysical relations many parameters must be observed on a global scale. The observation with microwave sensors on a space-borne or airborne platform provides a major contribution to this topic. The estimation of geophysical parameters from an isolated single microwave measurement is often accompanied by a high uncertainty. Hence polarimetric or multi-spectral measurements can be used to minimize this. Another important issue is the spatial resolution that has a direct impact on the physical dimensions of the sensor. DLR has developed the ANSAS instrument that offers a combination of passive high-resolution aperture synthesis imaging together with spectral sensing capabilities. The operation at a lower frequency range allows a high penetration depth in order to extract information about the surface and sub-surface or hidden objects. In combination with the aperture syntheses imaging principle the advantages of having various frequencies can additionally enhance the overall imaging capability. In this paper the basic idea of the experimental system ANSAS is presented, the setup and receiver assembly is outlined, and some first imaging results showing the capabilities of the concept are illustrated.